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AOR AR7030DRM AOR AR7030 Plus AOR AR3030 AOR AR5000 AOR AR8600 MK2 Alinco DX-R8E
Drake R7 Drake R8 Drake R8B JRC NRD-345G JRC NRD-515
Icom IC-R71E Icom IC-R72 Icom IC-R75
Icom IC-R8500 Kenwood R-600 Kenwood R-1000 Kenwood R-5000 Kneisner+Doering KWZ30 Lowe HF-150
Lowe HF-225 Lowe HF-225 Europa Lowe HF-250 Lowe HF-350 Palstar R30A Ten Tec RX-350 
Yaesu FRG-8800 Yaesu FRG-100 Yaesu VR-5000      


SDR - Software Defined Radio


CiaoRadio H101 CommRadio CR-1 ELAD FDM-DUOr ELAD FDM-S1 ELAD FDM-S2
Enablia TitanSDR Expert E. ColibriDDC SDR FM+ Microtelecom Perseus SDR RadioJet 1102S RF-Space NetSDR+
RF-Space Cloud-IQ RF-Space SDR-IQ Reuter RDR50B Reuter RDR54 S9-C Rabbit SDR Winradio Excalibur


Profi- Receivers

AEG E800/2

AEG/Telefunken E1800/3

Enablia TitanSDR Hagenuk RX 1001 M Icom IC-R9500 Lowe HF-235
Racal RA1792 Racal RA3712 Reuter RDR54 Reuter RDR55D RFT EKD 500 SRT CR91
Telefunken E1501 Telefunken E1700 Ten-Tec RX340 Watkins Johnson HF-1000    


Portable World Band Receivers

Degen DE1105 Degen DE1106 Eton E5 Eton / Lextronix E1 Grundig Yacht Boy 80 Grundig G6 Aviator
Panasonic RF-B65
Redsun RP300
Redsun RP2100 Sangean ATS-909X Sony CRF-1 Sony ICF-SW07
Sony ICF-S W7600GR Sony ICF-SW100S Sony ICF-2001D Sony ICF-SW55 Sony ICF-SW77 Tecsun PL-350
Tecsun PL-600 Tecsun PL-880        


Receiver Kit

Junior 1 from Stampfl          



The AR7030 still is a very well-known and still demanded shortwave receiver. Several versions are available:
First, the normal version without any special modification.
The "Plus" version offers more memory spaces, 400 in number. In addition, these can also be signed alphanumeric. Parts of higher quality seem to be installed, which should offer a better large signal behaviour. Also a notch filter/noise blanker unit can be installed without upgrading firmware on the "Plus" version.
Then there is another AR7030 with many other modifications, especially offered by Bogerfunk.
My AR7030 has a Schneider DRM unit installed. With this, DRM reception (digital radio mondiale) can be done together with a computer. Another modification was done on the bandwidth filter section: In addition to the normal filter, Juergen Martens built in a high-quality Murata 3.2 kHz ceramic filter K455J and a Collins 6kHz mechanical filter for me. The Bandwidths are as follows:
F1> 2.1kHz, F2> 3.2kHz, F3> 4.9kHz, F4> 5.5kHz, F5> 6.6kHz F6> 9.5kHz
Those two filters complete the others and give an even nicer, rounder sound to the AR7030, which already sounded good before.
Furthermore, the defective "Alps"-Encoder was replaced by a new one. But these Alps Encoders are not really good - they are imprecise. Smooth frequency changes are quite hard to do and need patience.
After researching, I found a "Bourns"-Encoder, which is much better than the cheap Alps-Encoder.
The Bourns Encoder which I got in my unit even has less impulses per turn of the vfo knob, namely 64.
The original Alps encoder had 100 impulses per turn. The Bourns Encoder contained in the AR7030 Plus even has 128 impulses per turn. Together with the new Bourns-Encoder, tuning over the bands is much better and more comfortable.
My AR7030 had the widely known IP+ modification inside, which I removed immediately, because the sensitivity of the AR7030 suffered from it. The slightly better large signal behaviour through IP+ therefore changes the sensitivity. In my opinion, this is not recommendable.
How does all this sound after all:
DRM works fine. Analogue reception is better owing to the new bandwidth filters, the receiver even gets more flexible.
Regarding large signal behaviour, the normal AR7030 does not differ from the AR7030Plus.
Using the ALA1530S+ antenna, the AR7030 works like on 20m long wire antenna. In the upper frequency ranges, some ghost stations can be heard.
A still recommendable receiver. Even if the new SDRs give more flexibility, an analogue receiver still is up-to-date!!



AOR AR7030 Plus

The AR7030 Plus is an extended version of the "normal" AR7030. Just better parts were used, like the VFO-Encoder by Bourns, which is much better than the old Alps-Encoder. But in my opinion this new encoder has too many impulses per turn. As soon as it is turned slightly faster, the desired frequency is easily missed. This also correlates with the too heavy flywheel effect. On the "Plus" version, also the firmware has been updated. Therefore an accessory board can be installed, which includes a noise blanker and a notch filter.
On reception I could not hear any difference to the normal AR7030. Regarding large signal behaviour, it still does not deliver, what the technical data promises. Its "predecessor" Lowe HF225 was at least equal.
On a 20m long wire antenne, attached via Balun, the AR7030Plus has its trouble. In the evening hours ghost stations can easily be heard on higher frequencies. Except for this, the AR7030Plus is a top receiver with real good audio and sensitivity.





AOR AR3030

The AR3030 features the legendary Collins filters, which it already has installed in the standard configuration. Its sound, the very low noise level and the nice and robust case in retro look are the advantages of this receiver.
Large signal behaviour unfortunately is not its strength. The AR3030 only copes with smaller antennas, a long wire antenna of 20m length was too much for it. Up to 10m wire is fine to work with, only in the evening hours the attenuator is necessary because the Rx overloads otherwise. Apart from this, for using this fine receiver it is recommended to use a preselector for tapping the full potential of the AR3030.
There also is the possibility to install a VHF converter, but this unit is very hard to find.





AOR AR5000

For quite a long time it is on the market - the AOR AR5000. It is known as one of the best radio scanners. It even is used in the professional sector - this means something! Its tuning range starts with 5 kHz and ends at 2600 MHz, which is an enormous range. All relevant operation modes and bandwidths are available. Even more - it is possible to install further bandwidth filters and other accessories. If the AR5000 also works on shortwave, I could test within the last few days. I challenged it with some of the best shortwave receivers.

Here is the main data of the AR5000:
Frequency range: 5kHz - 2600MHz
Modes: AM, LSB, USB, CW, FM
Bandwidths: 3khz, 6khz, 15khz, 30khz, 110khz, 220khz
Memories: 1000 (alphanumeric)
AGC: Off, Slow, Middle, Fast
Audio filters: high pass 0.05khz, 0.2khz, 0.3khz, 0.4khz / low pass 3khz, 4khz, 6khz, 12khz
In addition, there are many further functions which I cannot list all. Anyway, quite everything can be set up on this unit.

How is the reception on shortwave?
The AR5000 is a first league wideband scanner! Reception quality above shortwave is beyond any doubt! Well, on shortwave I have compared it with some pure shortwave receivers. The AR5000 is very sensitive! It can mostly keep up with the other receivers, namely the Icom IC-R75, Kenwood R-5000, Drake R8B, Perseus, RadioJet.
Unfortunately, the AR5000 only likes antennas, which are not too powerful. With a 35m long wire and as well on the Fenu-loop/HDLA3, the AR5000 has a very high noise level. The s-meter always is at S9 and above. A sign for it overloads! The sound in AM is hollow, in SSB it is quite good and audible.

Operation of this unit is quite painful due to the many knobs, because everything has to be set up manually.
The AR5000 may have an automatic operation, which depends on the frequency band. This is not very practical for shortwave and below. Operating modes, bandwidth, AGC have to be set up manually. The data is though not saved.
The AR5000 is recommended for FM listeners, so for everything above 30 MHz. Below, the AR5000 ist not really bad, but its direct competitor, the Icom IC-R8500, is much better on shortwave.

From the developers of HDSDR, the famous SDR control software, came the following hint - many thanks for it!
To our knowledge, the AR5000 is one of the very scarce receivers, which have a very wide 10.7 MHz IF interface, which I believe is 4 MHz. Therefore it is possible to combine the AR5000 with a Perseus SDR:
* Antenna connection on AR5000
* Connect Perseus to the 10.7 MHz interface of the AR5000
* Tune Perseus manually to 10.7 MHz
* Set AR5000 to AM mode to avoid frequency offset (might be due to the filters)
* Tune to desired frequency on AR5000

Even more interesting is the configuration with using the CAT interface additionally:
* install the Freeware OmniRig from
* copy the AR5000.ini file into the installation folder C:\Programme\Afreet\OmniRig\Rigs\ and adjust it
* select OmniRig in HDSDR and adjust: Sync LO, no Sync modulation
* set HDSDR setting under Options -> ExtIO Frequency Options -> "SDR Hardware on IF output" onto 10700000 Hz

This manual is meant for Users with advanced PC knowledge.

Written on 30. April 2012



AOR AR8600 MK2

The AR8600 Mk2 is a very good radio scanner which includes reception of shortwave and below, but also is quite difficult to handle. It includes so many functions which require daily operation for not forgetting how to handle and program it.
Above 30 MHz it can show its full power. In the classic shortwave bands, it cannot keep up with a Sony ICF-SW7600GR.
As expected, it only runs good on a long wire antenne with a preselector attached.
For scanner freaks a must.
For use on shortwave only limited recommendation.





AOR is probably the best known and most innovative manufacturer of radio scanners. Their latest product, the AR-DV1DX, is the first receiver on the ham radio market, which can handle both analog and digital signals. Like its bigger brother, the AR5001, the AR-DV1DX is one of the few receivers which combines digital and analog receiving technology. The AR-DV1DX is a direct conversion receiver from 100kHz to 18MHz and this feature makes it a SDR (software defined radio). From 19MHz to 1300MHz the radio uses the analog double and triple conversion technology. For demodulation, decoding and filtering of the signals downstream DSP (Digital Signal Processing) is applied.

Scope of delivery:
-- AOR AR-DV1DX receiver
-- Telescopic antenna with BNC plug
-- AC power adapter
-- 4GB SDHC memory card- (not in the picture)
-- German operating manual (if the radio was bought at "Boger-Electronics")
-- English operating manual (not in the picture)
-- Commandlist with control commands on CD (not in the picture)
The workmanship of the radio makes a good overall impression. The enclosure is made of lightly grey painted sheet steel and very stable. The front is made of white structured plastic. The nice coloring of the AR-DV1DX creates a welcome change from the widely used black colors used in radio manufacturing.  The three rotary knobs are also made of plastic and are arresting. The push buttons are all back-lit and have a precise pressure point. Because of its folding stand, you can bring the radio into a comfortable working position.
Most important data:
-- SDR and conventional double/triple conversion broadband radio
-- continuous frequency range: 100kHz-18MHz as SDR and from 18MHz-1300MHZ as double/triple conversion receiver
-- Analogous modes: AM, AM synchronous with selectable side bands, USB, LSB, CW, FM
-- DSP bandwidths: 200Hz, 500Hz, 1.8kHz, 2.6kHz, 3.8kHz, 5.5kHz, 6kHz, 8kHz, 15kHz, 30kHz, 100kHz, 200kHz
-- automatic attenuator
-- Auto Notch with three blanking widths
-- three-step noise filter
-- AGC: Slow, Medium, Fast and Manually
-- several squelch modes
-- adjustable voice inversion descrambler for analog signal,
-- 3VFOs
-- 2000 alphanumeric memories
-- 40 alphanumeric memory banks
-- 1 Priority channel
-- Recordings on the SD-card
-- time-controlled audio recordings
-- USB port
-- AUX jack for discriminator
-- solid enclosure
-- Dimensions: 178x50x215mm (WxHxD)
-- Weight: 1.5Kg

Operation of the AR-DV1DX

The AR-DV1Dx stands firmly on the table. Thanks to its rubber feet, it does not slide around at all. The volume control must be pressed. This arresting decoder and the squelch control beneath it are not very smooth. After depressing the orange display lights up and the AR-DV1DX is initialized within 10 seconds.  Frequency selection is easy. Enter the numerals (and if necessary the decimal point) and press "Enter". For mode selection you press the "Mode" button, select the desired mode and press "Enter". Programming the step size, frequencies and memory banks is more complex. Most functions are hidden in the secondary function menu and can be reached by pressing the "Function Key". Getting used to the double-function buttons takes some time. The German manual, which is supplied by the Boger company, is very helpful. Using the English manual is difficult, unless you have a good command of the English language. The control concept is similar to that of other AOR radios. Experienced AOR-users should not have a lot of difficulties operating the AR-DV1.

Due to the small dimensions of the enclosure,  the display is relatively small, too. But the dot-matrix display is light, readable and contains a lot of information about the status of the receiver. According to individual taste, the color of the push buttons can be blue, red, magenta, green, cyan, yellow or orange.

On the front, there is a USB port and a SD card interface. . On this 4GB SD-card, which is included, you can make audio recordings.  It is also used for firm updates and for saving the memories. With the "Commandlist", which is also included, the experienced programmer can remotely control the AR-DV1. It's too bad that this is restricted to the specialist. Unfortunately, AOR does neither  include  memory programming software or control software.

On the rear panel you can find the following connectors: DC-12V input, external speaker connector, AUX-output, BNC antenna input.

Although the AR-DV1DX is an ultra-modern receiver, it comes with an old-fashioned transformer power supply. Good for AOR!! As of late, most radios come with switching power supplies. which are cheap and cause interferences when listening to stations in the long-, medium, and shortwave range.


Reception on Long-, Medium-, and Shortwave

In order to assess the performance of the AR-DV1DX, I compared it to the ICOM IC-R8500 , which is also a broadband receiver.  But of course, the IC-R8500 belongs to a different price category.

For the test, the firmware versions 1512D and 1601B were used.

Both receivers start at 100 kHz and so a comparison on 147.3kHz is appropriate. On this frequency, the German Weather Service transmits in RTTY. For decoding I used the program "Zorns Lemma", which can decode Synop-coded weather programs.  Here, the AR-DV is at an advantage because it offers narrower filter widths than the IC-R8500.  My IC-R8500 only has  a 2.4 kHz filter. On long-, medium-, and shortwave I used the brand-new NTi ML052 antenna with a 4 square meter loop.

On 147.3 kHz, the AR-DV1 renders the better signal because of its narrower filter. As can be seen in the video, decoding is no problem.

The next test was on 7646kHz, another frequency of the German Weather Service just with a wider shift. Both receivers showed a flawless signal with no problem for the decoder.  At 3:17 min in the video you will notice a short intermodulation in the background which shows that on effective antennas, the AR-DV1DX tends to overload.

Reception from DWD on 147,3KHz & 7646KHz (HD)


A good reception of radio programs on long wave is only possible with appropriate antennas. Unfortunately, the AR-DV1 only tolerates effective antennas to a limited degree. . On the ML052, there were some intermodulation  and "ghost stations" to be noticed. The IC-R8500, on the other hand,  had no problems here. If you connect the AR-DV1DX with a passive discone antenna, e.g. the Diamond D-130,  reception on long wave is possible, but you will only hear the strongest stations. During daytime, reception of BBC on 198 kHz is almost impossible. What I noticed next, was the tinny sound of the AR-DV1DX.  The bass range was missing altogether.

On medium wave, reception was only possible with the Discone D-130. With the broadband ML052, intermodulation and a stronger noise level were noticeable. If you want to you use highly effective antennas for the AR-1DX, you need preselection or selective antennas, e.g., the Grahn GS5-SE.

Listening tests on short wave showed the same results, although reception was a little quieter. With the highly effective magnetic loop antenna NTi ML052, reception without overmodulation was possible during day time. When I used the Discone Diamond D-130,  the signal strength decreased, but reception of  the broadcast stations was better and the noise level was noticeably diminished. The automatic attenuator does not seem to contribute a lot to signal attenuation, in fact, it could hardly be noticed. If you connect the AR-DV1 to a highly effective antenna, you definitely have to use a preselector. I used mine with a high degree of success. The electronics of this preselector are by RFT and of high quality.  When the signal was filtered with the preselector,  reception was very good. Weak stations, e.g., Alcaravan on 5910kHz and Brasilia on 11780 kHz could be received well enough.

For AM-reception, the AR-DV1DX has a synchronous detector, which works satisfactorily. Unfortunately though, the selection of band widths is rather limited. I can't understand, why the 8kHz band width cannot be selected. With only 5.5kHz, the synchronous detector sounded rather muffled. For Synch-operation, only 5.5 kHz and 3.8 kHz are available. The synchronous detector has selectable side bands with the atypical labeling "SAH" for upper sideband and "SAL" for lower sideband.

SSB reception, on the other hand, worked remarkably well. With its 1.8kHz and the 2.6kHz bandwidth filters, the AR-DV1Dx sports sensible band widths.  Reception with the 2.6 kHz filter was especially very impressive. Amateur radio stations and professional Volmet stations could be received very well.


 Up to 18MHz, the AR-DV1DX is a software defined radio (SDR). Despite the fact that the AR-DV1Dx has a low pass filter, FM-flashovers could be noticed when using the broadband Discone Diamond D-130. Between 17 MHz and 18 MHz these were very noticeable and could be identified easily when I switched to FM and a bandwidth of 200 kHz.  After some research,  I found out that the transmitting antenna of the FM-station in question  was approx. 4 km away.  These FM flashovers could not be noticed when I used the ML052 because it has a FM blocking filter.

Boger Electronics recommends the following antenna types for the AR-DV1DX. Link.

Reception on FM, VHF and UHF

This is what the AR-DV1DX was built for, reception above 30MHz. When I compared this radio to the IC-R8500, there were small differences, which are of no relevance, though. With its good sensitivity, its selectivity and fast scan, the AR-DV1DX was convincing in the upper frequency ranges and was on par with the IC-R8500. As far as the selection of band width filters and complex scanning functions are concerned, the AR-DV1DX is definitely better than the IC-R8500. Thanks to the 100 kHz and 200kHz band width filters, FM-reception is especially good, the 100 kHz filter is almost suitable for DXing.  For such a modern receiver, RDS (Radio Data System) would have been desirable, though.

 Due to its 8.33 kHz step width, reception of aeronautical services in AM proved to be especially effective. The IC-R8500 does not have this step width. Because of its two squelch functions, "Level-Squelch" and "Noise-Squelch", the best setting could always be selected.  When switching to "automatic", both squelch functions can be used simultaneously. This worked better than the "VSC" function of the IC-R8500.

Amateur radio activity on 2m and 70cm is very rare in area.  At the weekend, I finally succeeded in receiving a few QSOs and almost no differences between the two receivers were noticeable, except for the audio. I noticed how tinny and treble-prone the audio of the AR-DV1Dx is.

Reception of Digital Voice

Now we are coming to the highlight of the AR-DV1DX: The reception of digitally encoded transmissions. In the meantime, all well-known manufacturers of amateur radios offer their own digital modes. Unfortunately, these are not compatible.  So far, the AR-DV1DX is the only receiver which includes all digital modes of amateur radio, decodes them and makes them audible.

If you select the "Auto" mode, the receiver switches automatically to the correct mode as soon as a signal has been detected and decoded. As already mentioned, the VHF and UHF activities of the local ham radio operators are rather limited and during the month that I had the AR-DV1Dx at my home,  I could not receive a single Digital Voice transmission!

Fortunately, a lot more is going on in Germany as regards Digital Voice. To get at least an overview of digital activity, I contacted Jochen Berns (DL1YBL).  Recently, Jochen has produced some informative videos for a test of the AR-DV1DX in the "Funkamateur“ magazine (2/2016). He allowed me to include these videos on my web page. Thank you, Jochen DL1YBL !


DMR_Nachbarkanal from Jochen Berns on Vimeo.


APCOP25_Phase1 from Jochen Berns on Vimeo.



DSTAR from Jochen Berns on Vimeo.


Yaesu_Fusion from Jochen Berns on Vimeo.



dPMR446 from Jochen Berns on Vimeo.


NXDN_IDAS from Jochen Berns on Vimeo.



DMR_Stoerung_bei_S1 from Jochen Berns on Vimeo.


YAESU_Fusion_C4FM from Jochen Berns on Vimeo.



DMR_1 from Jochen Berns on Vimeo.


The AR-DV1Dx is a special receiver in two ways. It combines a SDR and conventional, analogue reception technology and its highlight: "Digital Voice." Because of a lack of activity I could not test these digital modes. But as Jochen Berns' videos show, reception works without any problems and I refer to the tests in the "Funkamateur" magazine (2/2016).   I focused on the lower frequency ranges, instead.

To make full use of the potential of the AR-DV1DX, you should use a preselector.  Highly effective antennas, such as the ML052, the HDLA or the ALA1530S+ are too much for the input stages of the receiver, especially during the evening hours and at night.  The AR-DV1Dx tolerates the Discone Diamond D-130 or similar antennas a lot better. If you use passive antennas and do not want to do serious 'hardcore' DXing, you will enjoy the AR-DV1Dx.

The audio on long-, medium-, and shortwave is not very balanced. It is unusually tinny but offers good intelligibility. The AM-synchronous detector is surely a nice addition for such a type of receiver but it needs some tweaking. A 8kHz band width filter would also be welcome.  Because practically all functions of the AR-DV1DX are software based,  I am sure that AOR will make some improvements with firmware updates.

A big thank you to "Boger Electronics" for putting the radio at my disposal.

Product info AOR AR-DV1DX

DX Version
Boger Electronics offers the exclusive DX-version! "DX" is our quality seal! With "DX" you are on the safe side because you bought your radio from the only authorized dealer for AOR products in Germany! In Germany, we act as a manufacturer and take care of legal regulations such as CE-Conformity, extensive and checked German manuals, service and parts supply for at least 10 years.  (Quotation from Boger Electronics)



Alinco DX-R8E

A new shortwave receivers sees the light of day... The Alinco DX-R8E. Supposing that manufacturers of shortwave hardware would have stopped building receivers, now we are disabused.
The Alinco DX-R8 is in fact not a specially developed receiver, it descends from amateur transceiver Alinco DX-SR8, which is mostly identical with the DX-R8. Except for the microphone connector, which is missing on the R8. Alinco made it very easy that way.
The microphone connector was left out, but the slot stayed where it was built in. This does not look very nice.
I would even pay more for a front panel without this ugly slot. For selling the DX-SR8 as a pure receicer, the transmitter unit has been left out. When removing the top cover of the receiver, one is astonished when looking into this empty chassis. Yes, there had been the transmitter unit. The actual receiver is located in the lower half of the chassis. But even in this view one is asking: Isn't there anything else? A plate with some few components.
The chassis is of die cast aluminium. The front panel can be unscrewed and with an optional cable it is even remote usable.
The mechanical buildup can be named as stable. The big VFO-knob makes fun out of turning all over the bands. The big and brightly illuminated display looks really fine and informs on the most operating states.
The equipment consists of a bandpass tuning knob, a RIT knob - which is quite unusual for a receiver with 10 Hz tuning - and a lot of scanning functions. A special feature are the three switchable IF filters. But the AM filter of 9 kHz bandwidth is an absolute compromise. The filter might be of use for NFM. When I bought the Receiver, it was replaced by a high quality 6 kHz filter instead.
Another nice feature is done by the R8 additionally: There is the possibility to take an IQ signal via a 3,5mm phone jack to a PC. So you can send a small waterfall spectrum to your screen. Another optional cable even lets you control the R8 via the PC. So to speak as a pseudo-SDR. I did not test this function. But I heard from other SWL that it cannot be compared with a real SDR.

Here the main data:
Frequency range: 30 kHz - 35 MHz
Modes: AM, FM, USB, LSB, CWU, CWL & IQ signal output
3 IF filters: originally: 1 kHz, 2.4 kHz, 9 kHz (my R8 has 2.4 kHz, 4 kHz, 6 kHz)
Memories: 600, alphanumeric, various scanner modes

I compared the R8 with the AR7030 and the NRD545. Surely it is an unfair comparison, because these two play in a higher league. But the R8 puts up a good fight! The R8 is clearly designed for SSB use. Of course, as it was an amateur radio transceiver originally. In mode SSB it really works fine. It at least matches the other receivers! The SSB reproduction is noiseless and clear, so I have to say: Hats off!
In AM mode the tide turns. There it has a hard noise similar to the FM mode. But only, if strong stations are on neighbouring frequencies.
This might be a sign for a weak large signal tolerance. This was then confirmed in the densely packed BC bands. Close to strong BC stations, it mostly gave overmodulation. Maybe the R8 only likes passive antennas. I could not offer it such one. My main receiving antenna, the Fenu-Loop/HDLA2 does usually not deliver a too strong signal. Though the R8 regularly overloaded. The sensitivity is quite good. In that point, it really copes the reference sets. Except for below about 2 MHz where it is less sensitive.

It's a shame Alinco did not take troubles on the design. The slot for the microphone plug is like a punch on the eye!
Technically seen, the Alinco DX-R8 is a "low cost" unit, which you should not expect any wonder from. But it has its strong point: The SSB reception is really fine. I did not often hear something of that kind. Alltogether it nearly equals the Yaesu FRG100 with the FRG100 having the better large signal behaviour. Working with not too strong antennas, you can surely live fine with the Alinco DX-R8.



CiaoRadio H101

What is CiaoRadio? The term means "ComputerInterfaceAudioOutputRadio".
CiaoRadio is a so-called Software Defined Radio, shortened "SDR". As CiaoRadio is a completely digital device, its performance and as well the functional range is defined by the software. Filter bandwidths and other parameters are digitally generated and their impact is very effective. There is no need to buy expensive filters to give the receiver a better selectivity. The bandwidths can easily be adjusted with the computer mouse in the lower left of the display. Multiple notch filters can also be set simply by clicking the right mouse button plus then adusting depth and width continuously. Demodulation modes can be seen on the screen. The mode C-QAM is for AM stereo. This mode is unfortunataly not often used yet. Only France Bleu on 864kHz seems to be broadcasting sometimes in AM-Stereo. DRM reception of course is also possible when using DREAM software.
Installation is very easy:
Install the software, configuration according to the manual, connect CiaoRadio via USB, connect the antenna and then let's go.
Reception is, to say it at first, very good. All signals which can be heard with the existing equipment pool are also audible on the CiaoRadio. And this in even better quality. The CiaoRadio has a very low base noise level. By the way, it has an own soundcard built in. Those many demodulation opportunities and the continuous bandwidth filters just deliver a very good reception. Over here in Central Europe the antenna question always is a big topic.
During the day it works fine with 20m long wire! Only in the evening there are large signal problems, especially above 49m and 41m bands. Also below medium wave range the reception is weak in the evening. Down there it is overloaded with large signal effects. You will have to do some experiments on the antenna side. DX is possible if all requirements are fulfilled.

Update 20.12.2015:

For the CiaoRadio gives now an ExtIO.dll for working with HDSDR and other Software.






CommRadio CR-1

This mite of a device is so special that it has to be presented even before its arrival on the market! The CommRadio CR-1 is a wideband SDR (software defined radio) and a new development from CommRadio and the famous company Aerostream. Aerostream produces devices for aircraft radio purposes and newly wide band receivers. The CR-1 is a double superheterodyne with in-line 32bit DSP. The DSP produces the modes, bandwidth filters and other functions. The clou on this device - it is really small. Nearly too small, but then very tough built. Its housing is made of steel plate with a powder-coated aluminium front panel and the tuning knobs are of eloxadized aluminium. The OLED display is very small but pin sharp. If you position the widely known Lowe HF-150 besides the CR-1, the small size of it becomes apparent. 

WxDxH: 140 x 120 x 35mm

The CR-1 works on these frequency ranges:
150 kHz - 30 MHz
64 MHz - 225 MHz
437 MHz - 468 MHz
In modes AM, Auto-SSB, CW, FM and FMW. Auto-SSB automatically recognizes the modulated sideband.

It has 64 memory cells, scan functions and band selection options.For VHF & UHF must be noted that these are likely to be adapted to the European conditions. In the future, very interesting stuff for the CR-1 have been scheduled. CW & PSK31 decoding in plain text. Output on display or via USB interface on a monitor. Perhaps also a spectrum display.

Speaking about VHF & UHF, it is likely that these ranges will have to be adjusted onto the european conditions. There are some very interesting things planned for future: CW & PSK31 decoding in plain writing. Readout on the display or via USB connection on an external monitor. Maybe a spectrum diagram.

The CR-1 was mainly designed for outdoor mission. Electrical power can be supplied from a 6 - 18V mains adapter, via the USB connection or from an optional Li-Ion rechargeable battery pack (inside the device then). This battery is supposed to work at least for about 12 hours when listening on loudspeaker.
Power consumption is supposed to be 1 Watt maximum. There are three antenna connections, two of them for Long-/Medium-/Shortwave with BNC and phone jack, for VHF & UHF with BNC connector.

Concerning reception performance there is understandably no specification yet to be made, as the software is in beta stadium. First software updates will be coming soon. Then the CR-1 will be adapted for european circumstances.

Further information on

Update 07.03.2013

There is a Li-Ion accumulator built in the CR-1 now, which allows minimum 12 hours of operating with loudspeaker. The software has received some new functions.
Choosable bandwidths, depending on operating mode: 500Hz, 1kHz, 1.8kHz, 2.6kHz, 5kHz, 7.5kHz, 15kHz, 100kHz
Band preselection: amateur radio bands, broadcasting bands
Frequency band preselection: HF, VHF, UHF
Scanning speed for Memories and band scan: 100ms, 200ms, 500ms, 1Sek, 2Sek, 5Sek, 10Sek (retention time on frequency or memory)
Freely choosable side bands (USB & LSB)
Automatic & manual mode (change of tuning steps, mode and bandwidth filtes depending on range.

The first impressions of the CR-1 




Drake R7

I had to search for the R7 for a long time. It is very hard to find one in Europe, especially in mint condition. But I made it at last - mostly by accident. A visitor of my website offered me his R-7 for comparing and testing purposes. Isn't this trustfulness? :-)
So I received it short time after. The colleague from Brunswick was so kind to sell it to me in the end after I had told him, how long I had been searching for such a R7. So much for the preliminary events of this unit.

My R7 is nearly full configured, only the AUX-7 board is missing. Five high quality quartz filters are built in: 6 - 2.3 - 1.8 - 0.5 - 0.3 kHz. The sought-after noise blanker board is built in, too. This was a requirement as I have grassland fences in my direct neighbourhood, which nearly negate any reception due to their current pulses.

The R7 has been built until the 80s. So no wonder it already counts to the oldtimers. The hardware at least. Reception quality of the R7 still can cope with newer devices. Large signal behaviour is very good. On 35m long wire the R7 plays excellently without overloading.

I compared it with its younger brother, the Drake R8B. Which is a great device with full configuration and a brilliant sound. In mostly every matter, the Drake R8B is better, but not much. The R7 sounds thready and it is no very nice listening. But therefore the understandability in borderline situations is slightly better due to the missing bass fullness.
In addition, it is less noisy than the R8B which guarantees the reception of weakest signals. The R7 therefore is predestinated for DX! The handling needs a little time to get used to. A keyboard for frequency input is missing. The frequency has first to be preselected within a band, then with push-buttons in 500kHz steps near the desired frequency before it is fine-tuned with the VFO knob. But this is the handling concept of this device. There you still got something to turn. I like that! Alltogether a device which really makes fun. Except for one little thing which absolutely does not fit in this machine: The disastrous frequency drift. After half an hour operation time its frequency drifts about 500Hz! This is quite a lot. But luckily there is a modern electric circuit called "DAFC" (digital automatic frequency control). This circuit is placed on a little board which is built in the R7. Only a few wires have to be soldered and finally the frequency is rock-solid. Drift then around 4 Hz! So you can live fine with the R7. A great device and in addition not to be found very often in Europe. In the U.S. it is sold for astronomic prices.
Here are some audio comparisons with the Drake R8B: Comparisons

written on 2012-07-07




Drake R8

The Drake R8 is a really good and wanted shortwave receiver. Very good large signal behaviour and a very pleasant sound characterize this receiver.
I compared it with the JRC NRD525, which is equal to the R8 in reception behaviour. But even the R8 does have a weakness. The rubber keys are an impertinence. The tone control is not very effective and the synchronous detector does not cope with its reputation. Only in seldom cases it could really improve the AM reception. The handling is a little painful. E.g. the operating modes can only be switched in carousel manner. In addition, the bandwidth is switched to a software-given value. The last used value is not saved.
A VHF converter can be installed, but it is of limited use. Except for these weaknesses in handling the R8 is a Top-Rx.
The successors R8A and R8B were clearly improved in handling and partly even in reception quality.





Drake R8B

Like its predecessors, the Drake R8B is a very good shortwave receiver. It is even better! Some things were improved on it which gives an obvious increased performance. The Synchronous detector has been realized with choosable side bands. Even this is a big improvement in comparision with its predecessors. It is now as good as the synchronous detector of the AOR AR7030. But also the free choosable bandwidths are a reasonable improvement compared with the predecessors. Even the automatic function is freely programmable for your own needs. The tone control also has improved and now is good usable. Still annoying is the rubber keyboard itself which has not changed at all. In reception manner it seems to be itself again, generally speaking. Very good large signal behaviour and good sound.
I compared it with the professional receiver Hagenuk RX1001 M. Reception behaviour is comparable, except for the R8B having the significantly better large signal behaviour below 500 kHz. SSB reception is where it has to surrender, there the RX1001 M is definitely better. But the Drake R8B does not need to hide
from professional receivers. It is much more flexible than many professional receivers. In reception it can mostly cope. Unfortunately the R8B is not in production anymore. It is one of the newer classical shortwave receivers which really can satisfy, besides the AOR AR7030 Plus and the Icom IC-R75.
A top shortwave receiver!





For over a year after it had been announced in the summer of 2014, the ELAD FDM-DUOr is finally available.  After solving some technical difficulties, ELAD succeeded to offer for the first time  a flexible and powerful SDR receiver. As a table top receiver it has the most important functions, which are PC-controlled, e.g., spectrum display and many other features.  This is what many SWL have been waiting for. In the beginning of October, on a Tuesday, a DHL courier rang the doorbell and delivered a small parcel coming from Italy. It was hard to believe, but the FDM-DUOr had arrived. On the previous Saturday I had received notification from Franco Milan that my FDM-DUOr was ready for delivery and would be shipped on Monday.  It took less than 24 hours for the parcel to arrive from Italy. It couldn't have been any faster.

The FDM-DUOr comes in an inconspicuous box and is well packed. Additionally, the case and the display of the radio are protected by protective foil.

There are lots of extras that come with the FDM-DUOr:

-- anti-slip mat
-- 2 USB cables
-- Adapter cable USB>Mini-USB
-- Headphones extension cable with an angle plug
-- DB9 plug for individual configuration
-- 2 audio extension cables 3.5mm jack plug/jack plug
-- DC power cable
-- USB flash drive with the operator software and manuals

The constructional quality of the radio is very good. The case is made completely of black anodized aluminum.  The large VFO is also made of aluminum and easy to handle. The two small controls are made of plastic but they have an aluminum-like coating. Because of its foldable stand, you can tilt the radio into a comfortable operating position.

The most important features:

-- Table-top receiver or PC-controllable
-- Frequency range 9kHz-54 MHz, unofficially 54 kHz - 108 MHz
-- Modes as a table top receiver: AM, LSB, USB, CW, FM
Band width filters:
    AM: 5kHz-6kHz-7kHz-8kHz-9kHz-10kHz-12kHz
    SSB: 1.6kHz-3.1kHz in 100 Hz steps, 4kHz-5kHz-6kHz
    SSB Data: 300Hz-600Hz-1000Hz
    CW: 100Hz-300Hz-500Hz-1000Hz and 4 audio filters at 100Hz band width
    FM: Narrow-Wide-Data
-- AGC: Fast, Middle, Slow, manual
-- adjustable noise blanker
-- adjustable noise reduction
-- auto-notch filter with two selectable widths
-- 199 memories, alphanumerically writable via the SW2 FDM-DUOr manager at the PC
-- can be fitted with a total of 10 band-pass, low-pass and high pass filters (preselector)
-- sampling resolution: 16bit
-- sampling rate: 122.88 MHz
-- 10 MHz TCXO (temperature-compensated oscillator)
-- SMA jack for external 10 MHz reference signal
-- separate antenna jacks for HF and VHF
-- antenna jack (Ant.3) for upgrades
-- headphones jacks on front and rear panel
-- adjustable AUX-jack on the front panel and TX-mute on the rear panel
-- built- in monitor speaker
-- elegant, well-built aluminum case, black anodized
-- Size: 180x115x70mm (LxDxH)
-- Weight: ca. 1,2 Kg

Block diagram of the FDM-DUOr

Input stage
The signal of both antenna jacks is passed through an individually configurable preselector and then reaches the 16bit analogue/digital converter (ADC).
Fast DSP unit
The digitalized data then pass through the FPGA and are further optimized.
Digital I/Q and analogue I/Q
After that, the signal is directed to the PC via the USB 2.0 and is demodulated with the control program.
Stand-alone DSP unit
In this mode, the signals are passed through another FPGA and are processed for audio playback via the internal DAC-audio amplifier (Digital/Analogue Converter)
Human Interface Unit
This data stream contains information for the control and operation via the internal microprocessor, which makes operation without a PC possible.

With permission from ELAD

Front-End (Preselection) of the FDM-DUOr

With the configurable preselector of the DUOr, ELAD breaks new ground in building SDRs. The preselector has 10 slots.  Each slot can be configured individually with band pass filters and/or high pass/low pass filters.  ELAD offers plug-in boards for all ham radio bands.  Unfortunately though,  the needs of radio listeners have not been considered so far.  When the DUOr was launched, there were no band passes for the broadcasting bands available.  My receiver, which was one of the first ones, had three band passed built in, one of them in the beta version.  The other two came with the radio.

My DUOr had the following plug-ins:

-- Slot 1: 75MHz - 108MHz (Beta Version)
-- Slot 4: 13'600KHz - 21'500KHz
-- Slot 5: 21'500KHZ - 35'000KHz
-- Slot 6: 1'700KHz - 54MHz (Bypass of SW)
-- Slot 7: Low passfilter 1'700KHz

The receiver recognizes the plug-ins automatically and assigns them to the appropriate frequency range. If there is no plug-in for a frequency range, then a bypass  is automatically put into operation and this range is not filtered.

Antenna 1: 9kHz-54MHz (is passed through a low pass filter which suppresses signals above 54 MHz)

Antenna 2: 54MHz - 108 MHz (dependent on the built in band pass filters)

With permission from ELAD

Operation of the FDM DUOr

Finally, the small FDM-DUOr is on my table. ELAD was right to include a small anti-slip mat because the radio slides on a smooth surface, especially when you press one of the three encoders.  OK, let's go! On the front panel, you are looking in vain for an "ON" switch.  Just in the case of the FDM-S2, this knob is on the rear panel.  If you have the FDM-DUOr permanently installed in  your shack, switching the radio on is quite inconvenient.  You have to slide it forward to reach the sliding switch.  If you succeeded, the blue-lit display will appear. All symbols become visible for one second, which could be a self-test. The buttons E1 and E2 are encoders which also have a push button function.

With the Encoder 1 (E1) the following functions appear in this order:

Volume, Squelch, AGC On/Off, AGC Slow, Medium, Fast or Gain with AGC off, NR, NB, AutoNotch


The Encoder 2(E2) controls the following functions:

Band filter widths, CW pitch, RIT On/Off, RIT value

RIT means: Receiver Incremental Tuning. You can use this in case two SSB stations have a slight frequency offset.


The large VFO is non-locking and also has a push-button function. By pressing the VFO,  you will get into the step menu. A short push activates the "Quickstep" menu. The following step widths are available:

1Hz, 5Hz, 25Hz, 50Hz, 100Hz, 250Hz, 500Hz, 1kHz, 2kHz, 3kHz, 4.5kHz, 5kHz, 7.5kHz,  9kHz, 10kHz, 12.5KHz, 25kHz, 50kHz, 100kHz, 125kHz, 250kHz, 500kHz, 1MHz.

If you push the button more than one second,   you activate the "Digit by Digit" menu. Thus you can point to any digit in the frequency display and can select 10Mhz steps, e.g.


The DUOr in Action (HD Video)


The small blue Buttons have following functions:

Set to Memory
Push E2
Menu Settings
Memory mode
Quick Memory
VFO-Lock On/Off
Set Memory to VFO
Change Mode in the Memory
Show Memory Name or Memory Number
Menu Settings
Memory mode
Delete Memory
VFO-Lock On/Off

After some getting used to, working with the DUOr is relatively easy. After selecting the mode, band width, tuning steps, AGC threshold etc., you can finally start.  Or rather almost! Although the DUOr has a loudspeaker built in, you shouldn't expect a sound sensation. This mini-loudspeaker is more meant to be for audio-control and not for listening. A good active loudspeaker or good headphones are required.

Reception as a table top

For two months, I tested the DUOr intensively and compared it to the Icom-R9500, Lowe HF-225 Europa, Perseus SDR and the RFSpace Cloud-IQ.  For antennas I used my Fenu-CrossLoop/RLA4B (1.2m²) and the ML200 with almost 4m². Both antennas render high levels with best signal/noise ratio.

The first thing you'll notice is the quiet reception. The noise floor is very pleasant. Due to the AGC-threshold, you can reduce the noise to a minimum. But you have to make sure not to select too high a threshold, otherwise the receiver will become insensitive. The default value is 4, which is a good compromise.

The AGC-threshold is adjustable in 10 steps, which proved to be too coarse. The possibility of smaller steps would have been desirable.  On VLF, LW and MW, the DUOr beat the IC-R9500, which is a little insensitive in this frequency range.  On the other hand, the Lowe HF-225 Europa could keep up in these bands. Both receivers had about the same sensitivity.  But as far as strong signal immunity is concerned, the result was different. Here the IC-R9500 was the leader. The DUOr took turns with the HF-225. With the HF-225 Europa you could hear "ghost stations" above MW.  On the other hand, the ADC-Clipping light "PK" lit up, which points to an overmodulation of the ADCs. But there were no "ghost stations".

The audio of the DUOr is treble prone, which is good for intelligibility.  The music playback is a little tinny. In this respect, the analogue receivers are preferable.

On shortwave, the IC-R9500 was clearly the winner. No wonder! This luxury receiver has every tool necessary for improving reception. But the DUOr was not bad, either. It could receive weak signals just as good as the other two radios. It should be mentioned that the DUOr does not lose sensitivity in the higher frequency bands. In the 10m band, you had to make use of the IC-R9500's preselector to compensate for the loss of sensitivity. With the HF-225 Europa, very weak signals were buried under the noise.

Because of the individually configurable preselector, the DUOr showed no large signal problems but only as far as the filtered band passes are concerned. Outside these band passes, the ADC overmodulated and the "PK" indicator lit up very often but "ghost stations" were never noticed, which points to the fact that the DUOr has the same electronics for reception as the FDM-S2.  Both receivers reacted in the same manner.  The noise blanker, which can be adjusted in 10 steps, worked very well and effectively suppressed the interferences coming from a nearby pasture fence. In some cases, the noise reduction (NR), which can also be adjusted in ten steps, was helpful. For both these features, a better fine adjustment would have been desirable. 

SDR Reception via PC

I used the supplied ELAD SW2 software in the version 1­_107beta for the tests of the radio as an SDR controlled by a  PC.  In the meantime, this software offers almost everything, which the SWL or ham radio operator desires.  The DUOr can be configurated with the FDM-DUOr manager, which is integrated in the SW2 software. 

The following parameters can selected:

--configuration of the preselectors
--programming and labeling of the 199 memories.  Entries can be made manually or transferred from the Eibi-list.
--the color of the display can be continuously adjusted to any color

I compared the DUOr to the Perseus SDR and the RFSpace Cloud-IQ.   For all three receivers, I used the manufacturers' software. Concerning sensitivity the following can be said: The DUOr is on the same level as the Perseus, except for the higher frequencies, where the Perseus is not just as good.

Over the complete frequency range, the Cloud-IQ  is a little bit more sensitive than the other two receivers. All other factors, except for the preselection, are determined by the software.  In this respect, the SW2 is practically flawless and offers the most functions.  Only the slow spectrum of the SW2 spoils this overall impression. If you tune the radio with the mouse wheel, the spectrum follows with rather long a delay.  This also happened with the FDM-S2.

Other than that, the combination of the DUOr and the SW2 works flawlessly. As already mentioned,  the SW 2 offers a high standard and makes full use of the DUOR's overall qualities. DRM can be decoded without additional software. What is really nice is the possibility of combining both modes : table top receiver and PC-operation.  The table top can be tuned and listened to and at the same time you can watch the spectrum on the PC. To make use of this feature, you have to deactivate the SW2's"Snap" function.

Reception of FM is also possible, but it only works with the appropriate band pass filter.  For testing purposes, my receiver came with the FM- band pass filter in the beta version.  Generally, the DUOr can only be tuned up to 54 MHz. If you own the FM band pass filter, the radio has to be activated for FM operation. This is done in a system file of the SW2 software. If you start the software again with the radio switched on, the modified system file will activate the upper frequency range of the FM band. FM reception is only possible in the PC mode. Of course, the SW2 offers stereo reception of the FM bands. There is also a fast RDS indicator which shows all relevant RDS data.  For FM -Dxing, the combination of the DUOr and SW2 works very well.



The ELAD FDM-DUOr is a welcome addition to the receiver market.  At the time of testing, it is the only SDR reviver which combines the two features: table top receiver and PC-operation. Both alternatives can be used at the same time. This is completely innovative!  Because of its individually configurable preselector, the DUOr can be tailored to the listeners' needs.

Unfortunately though, some things are not quite fully developed. The software, which controls the DUOr in the table top mode, needs some fine tuning. There is the AGC threshold, whose steps are too coarse and also adjusting the noise reduction and noise blanker should be more exact. But ELAD tries constantly to improve the software. Therefore, it can be assumed that the small flaws will be corrected and new functions will even be added.

The lack of band pass filters for "General Coverage" must be criticized as well.  As of December 2015, the available band pass filters are only customized for the amateur radio bands.

The radio is an outstanding product. Top class!

posted 10.12.2015




The FDM-S1 is a Software Defined Radio (SDR) which can only be operated via a computer. It receives continuously from 20 kHz - 30 MHz and even up to 200 MHz in "oversampling mode". The software "SW1" offers the modes CW, LSB, USB, DSB, AM, SAM, DRM, FM and WFM. The tuning steps can be customized, as well as the bandwidth filters up to 24 kHz width. The maximum visible width of the spectrum is 3 MHz. Not to be forgotten is the spectrum recording function. All functions are software defined and can be enhanced or modified through software updates. The operation of the SW1 software needs a little getting used to. It is not as easy to use as the Perseus software. It offers many settings and configuration options. It is possible to import the the Eibi frequency list in CSV format. Of course other lists in the same format can be imported as well. It is also possible to directly download DX cluster frequency lists. The frequency list entries can be displayed in the spectrum as a function of the frequency. So you know what's going on at the tuned frequency. DRM (Digital Radio Mondiale) is decoded directly in the SW1 software. So you do not need any external software to receive DRM stations. What catches one's eye immediately, is the beautiful and responsive waterfall / spectrum display. It can be customized, but unfortunately it's not very easy. But usually you will not want to perform any big changes. Because it's nearly perfect in the original setting. A huge "plus" is the scalability of the waterfall / spectrum display. It adjusts to screen size and thus gives you a large display on a wide screen.  Tweaking the settings of the two manual notch filters is a bit cumbersome. But if you have some practice, it works quite well. Oh yes, an "auto notch" is also available. You'll be using it most of the time anyway. The SW1 software comes with a very effective noise reduction that is second to none. I have often used this function. It produces virtually no digital artifacts. Recently a noise blanker (NB) has been integrated. Although still a beta version, it works very well. But it can't beat the NB of the Perseus software. So, these were the most important features related to the software. I tested the version 3.15Beta.

How does it compare to the Perseus??

The Perseus costs almost twice as much as the FDM-S1. So is this a meaningful comparison? Yes, it is! The FDM-S1 is a good match for the Perseus. Regarding sensitivity and clarity they are very close. The Perseus has the lead by only a small margin, because its audio is a tad biased towards treble and thus more intelligible than the Elad. But just by a slight margin. Where the Elad has to make a few concessions is large signal performance. On my antennas, a 35m long wire and Fenu Loop / HDLA3, the S1 sometimes suffers from overload during the evening and night hours. The Perseus remains largely in the linear range. But the Elad can be retrofitted with an external preselector. Then it will probably be able to catch up with the Perseus.

The bottom line, I believe the Elad FDM-S1 is equal to the Perseus in most areas. Except in large signal performance. The SW1 software offers many configuration possibilities and DRM without external software. And a big plus for the SW1, it is freely scalable up to screen size!

Great performance at a fair price. Almost an insider's choice the ELAD FDM-S1!






Elad has become a well-known name in the SDR world. The small Italian company based in Caneva, north of Venice, has contributed its share to the SDR development in recent years. Elad does also offer interesting antenna splitters and distributors. The FDM-S2 became available in early 2014 and sparked an interest in the shortwave listener community since its release. It is the direct successor of the FDM-S1 which was quite successful. The FDM S2 should be even better!

The most important data:

- Sampling rate: 122.88Mhz = 9 kHz - 52MHz (direct sampling) / 74 - 108Mhz & 135 - 160MHz (in undersampling mode)
- Sampling resolution: 16bit = up to 96dB dynamic range of the A / D converter.
The dynamic range is further enhanced by processing of the 122.88 MHz signal in the FPGA.
- Low pass filter at 54MHz
- Bandpass filters for VHF & VHF
- Separate antenna connectors for HF & VHF
- All connectors on the rear panel
- On / Off switch
- Frequency range: 9 kHz - 52MHz, 74 - 108Mhz, 135 - 160MHz
- Spectrum Visibility: max. 4.951,2Mhz
- Elegant, beautifully crafted aluminum housing, black anodized.
- No separate power supply needed. Operating voltage 5V via USB port.
- Remote control via the local network (only with the Firefox browser).

Inside of FDM-S2

With kind permission of ELAD

Software SW2

The new software looks very similar to the old SW1. A few additional functions give a professional touch to the software.

The highlights of the SW2:

- Four virtual receivers
- DRM fully integrated into the program. No third-party software required.
- Excellent FM stereo reception
- Suitable for FM DX
- Very fast RDS
- Freely programmable band preset buttons

The most interesting feature are the four independent virtual receivers. It is possible to set these receivers at four points in the visible spectrum. A 5Mhz spectrum can contain up to three shortwave broadcasting bands. To compare reception you can put a receiver in each of the three bands and compare reception quality. Each of the four receivers stores the last used frequency, mode, bandwidth, volume, squelch, etc. Also the band preset buttons that are freely configurable in the menu are a good idea. So you can program your own "shortcuts". A recording function must not be missed. The SW2 has an easy to use scheduler, where you can program multiple recording times, much like a VCR. The spectrum or audio recordings can then be played at the desired point in SW2. The spectrum recordings can be tuned as if you were listening live. As in SW1, four different frequency databases can be displayed in the spectrum. One database can be created by the user and can contain an unlimited number of frequencies and can be displayed in the spectrum. Not to mention, the freely scalable spectrum! The SW2 has two separate windows in which the audio signal and the IF signal can be processed. It's a pity that the IF window doesn't allow bandpass tuning in AM mode! The next downside is the lack of choice of the sidebands in AM synchronous mode. The controls on the right side and the red main frequency display are well too small. On a high resolution screen the controls are poorly visible. You have to be very close to the screen to see where to click.

The S2 can be controlled remotely over the local network with the "USB Web server software" that only works with the Firefox browser.

There would be a lot more to report, but that is out of scope. Best to download the software SW2 and try it out yourself.

Download for SW2: SW2- software

Download the files which can be played in SW2: WAV files

Given the positive feedback in the forums, I was looking forward to the FDM-S2. Franco Milan, the owner of Elad, provided me with a brand new FDM-S2 for unlimited time. So I could test the new device properly without any time pressure.

About three weeks I tested the FDM-S2 and compared it mainly with the Perseus. During this time, four software updates were released. One update even corrected bugs that I had reported. This shows the manufacturer's interest to provide a well-functioning software. Great service! The software installation is fast and without problems. After the first start you have to familiarize yourself with the software. Users that already know SW1 have fewer problems of course. The first thing I noticed was the tedious entry of frequency in "Hz" (Hertz). This is unusual. After some searching I found where to switch it to "kHz" in the settings. Many settings can be made in these menus. So for a start I made myself familiar with these. The then current software version was V1.28 and I noticed a few things that needed correction.

But now to the reception!

Generally speaking the Elad FDM-S2 with its original software SW2 produces slightly less noise than the Perseus. Also the latter using its original software. Low-threshold signals are slightly better readable with the Elad. This is noted in SSB and AM alike. If you want to reduce the noise further, you can help yourself with the digital noise reduction (NR). It works better than the NR of the Perseus. The sensitivity of both contestants seems to be about the same. I couldn't determine any differences. Personal listening habits are what decides the clarity in such a case. Both receivers are really head to head in this respect. What is not so good at the FDM-S2 is its mediocre large signal behavior. On my currently used antennas, a 15m long wire with a 1: 9 Unun, the FenuLoop / HDLA3, Fenu-BigLoop / RLA1B and the Boni whip, the "ADC Clip" display lit up very often. This indicates clipping of the analog / digital converter. In other words, the A / D converter sees too much antenna voltage. But I could not find any distortions or ghost signals. After switching on the attenuator, the ADC clip no longer lit up, however at the cost of reduced sensitivity. It remains to be seen whether this warning is an "early warning" before actual clipping. Very successful, however, is DRM reception. To this end, all that is needed is already integrated in the SW2 software. The DRM schedule has online access to a frequency database and is always up to date. Of course, only if there is an Internet connection. A second window displays the station name and other information that are being broadcast. The FDM-S2 does also receive FM and a section of the VHF band. On FM, the combination S2 & SW2 can fully convince. FM has a very good sound and invites you to linger. RDS is very responsive and works surprisingly well even at weaker stations. The bandwidths on FM are almost infinitely adjustable between 25khz and 192khz. This makes the FDM-S2 interesting for FM DXers. Between high-power transmitters, using a bandwidth of about 60KHz, weaker stations become audible. Due to lack of signals and appropriate antennas, I could not test the VHF range appropriately. A few local radio amateurs were heard a short time.


The FDM-S2 is a very serious opponent for the Perseus! It costs about 300 euros less, delivers absolutely the same reception performance and even goes beyond with the fully equipped SW2 software. FM & VHF is included in the FDM-S2. In the case of the Perseus FM + must be purchased to receive FM. The SW2 software holds many a function to be discovered by radio amateurs and SWLs. Only the overload problem * is a minus point in the otherwise excellent rating!

* After consultation with Franco Milan, the head of ELAD, the "AGC clip" is lit when levels are exceeded even for a very short period of time. This behavior will be improved shortly. The Perseus with its built-in preselector still has the advantage. Anyway, as far as antenna signal levels are concerned.

A note at the end: I have been using software versions from V1.25 to V1.28 during my tests. These still contained several bugs. It is to be expected that Elad will further improve the software and new features will be added.

Thanks to Franco for the loan of the FDM-S2.

Posted 08/08/2014






Expert E. ColibriDDC SDR

Since 2009, the small Russian company Expert Electronics has developed and produced digital amateurradios.  The main product of this company has been the SunSDR radio.  The SunSDR-MB1, a standalone -SDR,  has already caused some stir in the ham radio scene. Lately, Expert Electronics has produced a SDR-Receiver: the ColibriDDC SDR.

Main Features:
Frequency range: 90KHz - 55 MHz (with external filters up to 800MHz)
Modes: AM, SAM, DSB, LSB, USB, CW, DIGL, DIGU, FM, WFM DRM (depending on the software)
Selectable Attenuator: 0/20dB
Broad Band spectrum: 62 MHz wide
2 independent receivers
TXCO,  temperature compensated
14 bit A/D converter
24bit DAC-Soundcard for  directly connecting headphones or active loudspeakers
SMA antenna connection
SMA jack for an external reference signal
Connection option for extensions via a DB15 connector for 7 freely assignable switching signals
LAN connection to a PC
5V operating voltage
Size: 64x24x112 (WxHxD)
solid and silver anodized aluminum case
Supplied accessories
Colibri SDR
Switching power supply
2m LAN cable
Adapter SMA>PL


The Colobri has three connectors. "REF" is a SMA-jack, which can feed the receiver with a very stable reference signal. The "EXT CTRL" jack is for optional external accessories, e.g., preselector, antenna switch etc.
The incoming signal first passes a low pass filter, before it reaches the 0/20dB attenuator.  Then the signal is digitalized in the A/D converter and is passed on to the FPGA where the frequencies are selected and the dynamic range is improved. The digital signal then goes to the PC via LAN and can be controlled with the software.  The audio is also passed directly to the built-in DAC and can be taken directly at the receiver.

Vasily Vasilev from Expert Electronics made the Colibri available for three months to conduct tests and make comparisons.  To test the radio with a wide variety of antennas, I used:

-- Fenu-CrossLoop/RLA4B
-- Clifton Labs. Z1501F
-- NTi MegActiv 305
-- NTi ML 200
-- Dressler ARA500

For comparisons I had the tried-and-tested Perseus receiver.

I conducted my tests and comparisons not only at home, but also outside. In this case the NTi MegActiv and the NTi ML200 were a good choice because they are built for portable and stationary operation.

The Colibri SDR can be connected either to the RJ 45 jack of the PC or to a router. When operating I connected the radio to a Netgear-Router with its faster data transmission and ease of use via the local PC-network.

The Software

The installation of the ExpertSDR2 software went fast and without any problems.  A double-click on the appropriate icon starts the software but not the receiver. Only after a hopeful click on the ON/OFF button in the upper left corner,  the Colibri started with an audible click.

Wonderful! The software recognized the receiver right away without having to do complicated network configurations.  The ExpertSD2-software makes a good first impression. It is not cluttered and neatly arranged. The spectrum  and the waterfall are well designed.  The colors can be user-defined, you can even insert your own picture as a spectrum background. The "dBm"display can be controlled very fast depending on the noise and the signal level. The speed of the spectrum and the waterfall can be controlled in the menu.  The scalability of the spectrum is a helpful feature. If needed, the spectrum can fill the entire screen.  The amateur bands are pre-defined, which is very practical. It would have been even better if these buttons could also select the broadcast bands. Each button keeps the selected mode, bandwidth and zoom factor.

The software has two highly effective noiseblankers (NB), which can be configured at will. There is also an automatic notch filter (ANF). Its levels are selectable.  The Colibri also features a noise filter (NR), which can also be configured. Last but not least: The AGC! There are six settings, all of which can be user-defined.

In case you want to work with decoding programs, you can choose VAC (Virtual Audio Cable) for a connection.  For this purpose, the ExpertSDR2 Software offers some settings in the menu.  For CW fans, the CW-Skimmer-Server can be addressed directly. Besides equalizer, binaural-audio, audio mixer for the RX-channels,  2VFOs, Eibi-list, alpha-numeric memories , there are a couple more  features that could be mentioned. But that is beyond the scope of this article.

Receiving qualities

After some getting-used to, I started with 23.4KHz. With the MegActiv, the Germany navy station DH038 could be received very well. In comparison with the Perseus,  the were no differences in signal strength. But the sound was sort of 'quieter'. The ExpertSDR2 software has a little less noise than the Perseus software.  Even with the Clifton Labs. Z1501F, which produces high signal levels in the VLF range, there were no problems. Also on 147.3 KHz, the German DWD (Weather Service), no differences in reception could be detected. 

On all antennas, reception in the long wave range was very good as well.  The CrossLoop , which can be rotated to receive signals from different directions, could show its advantages. Perfect reception of weak stations! But something  strange could be noticed,  when I used the Clifton Labs. Z1501F. The entire spectrum was sort of fidgeting. When I switched to the Perseus, the spectrum was quiet.  It seemed as though the Z1501F produced too a high signal level for the Colibri. This phenomenon could not be noticed with other antennas.

As regards the medium wave, there was no difference to be noticed to the Perseus. You can only judge the reception qualities of a  radio when you try to receive even the weakest signals.  Not only is the sensitivity of importance, but also the audibility of a signal. There was a small difference between the two receivers. The ExpertSDR 2 software renders the signals a little crispier. With the selectable 18-band equalizer you could custom- tailor the audio. That increased the audibility a tiny bit more. Up to the 10-meter band, the Colibri is on par with the Perseus.  Only the somewhat higher sensibility of the Colibri on the higher frequencies makes this radio a little better than the Perseus.

Because the Colibri makes reception up to 8oo MHz possible, I listened in on the FM-band and used the Dressler ARA 500. Reception was rather good, but  image frequencies from the shortwave bands occurred.  Because of the lack of preselectors, reception above the FM-band was full of image frequencies and was not possible at all.

Fullscreen mode with 312 spectrum width
Possible spectrum widths: 39KHz, 78 KHz, 156 KHz and 312 KHz


Fullscreen mode with 312 spectrum width with the wideband spectrum 0-62MHz displayed.
A click on the wide band spectrum immediately goes to the desired frequency. The marked bands in the WB spectrum are to be seen.


Smallest possible adjustment without spectrum. The spectrum can be scaled continuously.


Comparison between ExpertSD2 and Perseus. ↓

In the picture below, the effect of the noiseblankers of the two soft wares can be noticed by the horizontal stripes. Because the NBs of the ExpertSDR2 software can be configured, they are superior to the ones of the Perseus.


DRM reception works well with DREAM.


In this picture, you can see the software of the second receiver.  Both receivers can be controlled independently.  Because of  the mixer function, there is the possibility of listening to the audio of both receivers simultaneously  or Rx1 on the left headphone channel and Rx 2 on the right channel. This is a great tool for comparisons.  Both receivers have two VFOs additionally.


In the lower picture, you can see FM-reception of the SWR3 radio station with the memory channel displayed.  Here you can store and label frequencies.  The S-meter and the 18-Band equalizer can also be seen.


RTTY reception from DWD on 147.3Khz with ZornsLemma.


The Colibri SDR is a high-quality receiver in mini size! The reception leaves nothing to be desired. The software ExpertSDR2 is very neatly arranged and easy to be operated despite the numerous adjustment options. But you do need a manual, nonetheless, to be able to understand all its functions and possibilities.

Unfortunately, the Colibri has no preselector, only a low pass filter at 55Mhz. This can result in overload,  which happened when the E-field Clifton labs Z1501F antenna was used.  This high power antenna could only be used during the day and even then the noise level increased considerably.  With the other antennas, no such overloads were noticed.

The efforts of Expert Electronics to correct software bugs as quickly as possible  are very laudable.  When I reported a bug in DRM reception and in the memories, barely a week went by before they got rid of the mistakes.

posted at 14.05.2014




The JRC NRD345G is perhaps the least-known JRC among the amateur radios.  While everybody was waiting for the NRD 545, the NRD 345 appeared first on the market.  Well, what sort of receiver is this radio? Where it says NRD, it doesn't necessarily mean JRC. After I had been trying out the radio for a couple of hours, I had the feeling that I had a AOR-radio in front of me.  The operation and the receiving characteristics were somehow not typical of JRC. It rather seemed to me that I was operating an AR3030. Other SWLs also had the same experience as I found out on the internet. How is the operation of the NRD 345G? In short: Simple and that's all that must be said. How is reception? As is the case with other (AOR) receivers, there are some problems when using big antennas. The NRD345G can handle a 20m longwire only during daylight.  Above 6200KHz there are large signal interferences.  In the evening,  a half way decent reception with a 20m longwire is not possible. A preselector is absolutely necessary.  Even a modified, vertical CB antenna is too much for the NRD 345. Just like the Kenwood R-1000, the NRD 345 works best with the short AOR SA-7000 antenna.  With this antenna, the NRD 345 can show what it is capable of.  Here you can really say that good reception does not require long antennas. Stations which I can just  receive with my favorite  receiver, the NRD 525, on a longwire antenna, can be also received with the NRD 345G using a short, 1.80m long SA-7000 antenna, albeit rather weak because of the short antenna. I would like to emphasize one feature: Seldom have I had a receiver with so little inherent noise.  Really superb! Even the weakest stations are audible provided no local interferences disturb reception. Even if very little points to the fact that this is really a JRC, it can be said that this is a very good receiver.  Hats off to JRC (AOR)!!

Highly recommendable with short receiving antennas.






The JRC NRD-515, in this case with the memory unit NDH-515 and the loudspeaker NVA-515, was a major success. The NRD 515 impressed by its easy operation, really simple. Also the sound of the radio was convincing compared to the subsequent models, the NRD 525 and NRD 535 which sounded rather muffled.  The large signal rejection was good, sometimes there were some distortions in the evening. Between 6200KHz and 6700KHz stations could be heard clearly which did not belong there.  The memory unit NDH-515 had 24 memories which were selectable with the channel switch. That was sensational for the technology at that time. In short: An almost professional receiver and still to be taken seriously .  






Who does not know the JRC NRD-525? It still is a sought-after receiver. And rightly so. As far as large signal rejection, sensitivity and the possibility of signal processing are concerned, it still is one of the best receivers. With the NRD-525 you are very well equipped for chasing short waves. But the 525 has its flaws, too. The biggest of them is that it sounds very muffled. The second flaw is that the NF amplifier makes a lot of noise.  These unpleasant features can be got rid of with a very effective modification.  The Kiwa-modification, e.g.,  gives the radio a completely different character.  I had to find out, though,  that not all 525 have this problem.  The NRD-525G /Serial No 51505) are rather free of noise.  But with  the older 525s this noise  becomes quite annoying when you listen to the radio for a longer period of time. The tone control isn't' even worth mentioning. It is a pity that the manufacturers did not pay more attention to the audio stages of the receiver. Too bad, with such an expensive radio at the time,  better audio would have been warranted.  The NRD-525 can be highly recommended with the audio modification by Kiwa.




JRC NRD-535D (Kiwa-modified)

From a technical point of view, the JRC NRD 535D is not different from the  NRD 535 DG. The 'DG' model is the one for Europe, the 'D' version  was sold in the USA. Both versions have 'BWC', the variable band width board,  "ECSS", the synchronous detector board and the 1 KHz band width filter.  The difference between this 535D and the normal 535 versions is the Kiwa-modification.  It improves the audio considerably because the audio sounds fairly muffled in the unmodified version.  This modification changes the frequency response in such a way that you might think it is a totally different radio. The AGC was modified as well. The 535 is very sensitive to electrical impulses coming from a light switch or from the crackling sounds of an approaching thunderstorm.  These impulses cause the S-meter to go up and it takes a long time for it to come down again.  During  this time, however, the radio is deaf.  That means that there is no reception possible.  The AGC-modification solves this problem.






The NRD-535DG is a well-known and much sought after receiver made by JRC. It can be viewed as a further development of the NRD-525. It is characterized by its immunity to large signal interferences. The NF-amplifier was improved so that there less noise than with the NRD-525. But the typical muffled sound is still present. New technical features were added:  continuous bandwidth control and the ECSS board. The bandwidth control is not very steep and does not make much of an impression. But it still helps. Only from serial number 56005 on, the "BWC" could control the 'inter' and 'wide' filter positions. Receivers with a lower serial number could only control the 'wide' filter.

The ECSS board also has its flaws. Similar to a synchronous detector, it improves the reception of AM-broadcasts in most cases, but after some time the oscillator starts to drift and synchronization is lost. This only happens with badly aligned receivers. Additionally for CW or digital modes, there is a high-quality 1KHz quartz filter built in.

The NRD-535DG is identical in construction with the NRD-535D (USA version) and has the same features as the NRD-535DG. Kiwa offers the well-known modification for this radio, which can be highly recommended.





I hardly could wait to have this receiver on my table. The NRD-545 DSP can only be compared to its older brothers with difficulty.

The operation is as usual. Anyone who has owned a NRD will be familiar with it quickly. But as far as the bandwidth filters and the audio are concerned, you have to orientate yourself anew. The bandwidth filters are unusually steep so that you have to turn the tuning knob slowly otherwise you end up on the wrong frequency. As far as selectivity is concerned, the NRD-545 DSP is absolutely top class. The bandwidths can be controlled continuously from 40Hz to 9.99 KHz, either in 10Hz increments  or in 100Hz steps. The notch filter and pass band tuning are also digitally generated and extremely effective.  There is also a digital notch filter and noise blanker. Unfortunately, the noise filter does not work very well.  It produced digital artifacts and even made the signal more difficult to read. The sound of the NRD-545DP requires some getting used to. In AM it sounds rather sharp and aggressive.  Additionally, the receiver makes noise, when no signal is present. As soon as there is a weak signal, the noise disappears into the background and the signal is like punched out from the noise. The readability is even better in SSB.

The large signal rejection of the NRD-545 is worse than the one of the previous models. That has to do with the DSP. The radio does not tolerate strong signals. Active antennas, e.g., the ARA60, are not suitable. You are far better off with a passive long wire. With a converter board, the range of the NRD-545DSP can be extended to 2000MHz. This board cannot be recommend unconditionally because it is badly suited for the upper frequencies and far too expensive.  You do a lot better with a scanner.

Anyone who listens more to AM-broadcasts should listen to the NRD-545 first before buying one. This is very important to avoid a bad buy especially because the receiver is not cheap.

The NRD-545 DSP is mainly for SSB listeners because in this mode it offers the whole range of options.  For AM it can only be recommended with reservations. First of a all, an adjustable AGC!!




Icom IC-R71E

The IC-R71 was built in the mid 1990s. It was modified several times, from the R71 to the R71E. At the same time, the JRC NRD-525 was also on the market, which was seen as its competitor. Its reception performance are similar to the NRD-525. Just like with the older NRD-525, this receiver's flaws are the same: the noisy NF-amplifier and its partially illogical operation (filter switches). When switching from USB to LSB there is a curious and unusual frequency shift of about +/- 1.5 KHz so that the radio has to be retuned every time. When used over a longer period of time, the R71E gets rather hot which is bad for the electrics in the long run. You better make use of the 12V operation in order to avoid the 220V transformer. This modification is not exactly simple and should be done by a specialist.  Or you could use a ventilator which takes care of the excessive heat. In my R71, I replaced the AM-Filter with a 6KHz Kiwa-filter. This is narrower than the original filter. All in all, a receiver with a good  large signal rejection which is on par with newer radios.




Icom IC-R72

I came upon this IC-R72, which had never been used, by accident. The receiver is brand-new, although it is at least ten years old. It came from a liquidation sale and was in its original box. The IC-R72 is the direct follow-up model of the IC-R71. It  excels by its good reception qualities and its easy operation. The reception is similar to that of the IC-R71.  What is a bit annoying, is the hissing noise of the NF pre-amplifier. It is hard to understand, why ICOM is not capable of building a better NF-amplifier, which would not be more expensive. Fortunately, you can fight the hissing by using an external NF-Filter, e.g., the Timewave DSP-9. As far as reception is concerned, the IC-R72 is almost on par with the NRD 525G. The IC-R72's strong signal handling capability is very good, but there often is a whistling sound caused by interferences in the closely packed AM bands which is due to too wide an AM-filter. In this case, you can switch to SSB and can listen to the transmission without interference. In SSB, the IC-R 72 is completely in its element. It really sounds superb! One disadvantage is the operation of the IC-R72 when using the internal 230V transformator.  It becomes so hot that you can turn off the heating in your shack. But luckily, the IC-R72 has a 12V connector and so you can operate the radio with an external power supply. All in all, the IC-R72 is a good and easy to handle receiver.




Icom IC-R75

The IC-R75. The final shortwave receiver by ICOM? Probably! But it's still being built but not sold in Europe anymore. It is still available in the USA, Australia and Japan. Additionally, it is rather inexpensive taking the built-in DSP-board into account. It costs about $650.00. So, the IC- R75 is a hot contender, if you want to buy a new stand-alone receiver. This very good receiver is in the same league as the AOR AR 7030, its strong signal handling capability is even a little better. Using a 35m long wire antenna and the Fenu-Loop/HDLA3, the R75 worked without any problems. The best feature of this radio is its double band pass tuning (PBT), so you can reduce the widths of the filters. This is very effective in the SSB mode. The DSP can reduce the noise in 15 steps. The automatic notch filter is also very useful of suppressing whistling noises. Additionally, the R 75 has 100 alphanumeric memories and 2 pre-amplifiers. A word of caution:  Overmodulations may occur in the evening when playing around with the preamplifiers.  The R75 can be controlled very well by PC, especially the software 'HamRadio Deluxe' can be highly recommended. The R 75 is still a top receiver.




Icom IC-R8500

The IC-R8500 is not exclusively  a shortwave receiver, but it has to be taken seriously for shortwave reception, nonetheless.  The frequency range is from 100 KHz - 2000MHz continuous. Compared to other shortwave receivers which I own, the R 8500 often has a better reception quality. Due to its 5, 5 KHz filters, it sounds bright and detailed.  But in reality it is more than 8KHz wide with a bad shape factor at that. The reception of stations in AM is often accompanied by a whistling sound due to interferences. In its defense, however, it has to be said that even mere shortwave receivers have the same problem. On an undisturbed frequency, the R8500's performance is convincing and on SSB it is superb. ECSS-reception (listening to AM in SSB) is no problem because the frequency stability of the receiver is very good. For a broadband receiver,  its large signal immunity on big antennas is outstanding. The reception above 30MHz is beyond any doubt. Anyone who is looking for a radio, which  receives (almost) anything in top quality, does not get around the IC-R8500.




Kenwood R-600

The Kenwood R-600 is a really a down-graded version of the R-1000. It only has the most essential features of a shortwave radio but with the same electronics for receiving. The R-600 receives from 0 - 30 MHz in AM, USB, LSB and CW. There are no memories. You switch  the radio on, select the band with the band selector, select the frequency with the VFO (which is smoother to handle than the R-1000's) and off you go.  The sound of the built-in speaker is very good and there is practically no NF- signal noise. After a warming up period, you can listen to broadcast stations in SSB. That works very well but you have to turn the VFO very carefully to select the station. The R-600 does not always tolerate large antennas; during the day it can handle a 20m longwire with some difficulty. In the evening, all hell breaks loose and the R-600 overmodulates just as  badly as the R-100.  But the R-600 works very well on a short antenna, e.g., AOR SA-7000 or the Diamond D-130.  It becomes apparent once again:  good reception does not necessarily depend on large antennas.  The R-600 serves all listeners well  who want to listen to shortwave without complications and much effort. The radio looks good, is solidly built and does not have to hide from its bigger brothers. But it has its problems with larger antennas. Just like us, the R-600 is getting on in years. Anyone who wants to buy this receiver has to be aware of the fact that it might have defects simply because of its age.




Kenwood R-1000

The highly-praised reception quality  of the R-1000 made me buy one. Of course,  I was very excited.  Firstly, you can say that the R-1000 is very easy to operate.  It is the right receiver for the beginner.  You can compare the operation of the R-1000 with the one of the JRC NRD 515. What about the reception quality of the receiver?  You  will notice that it does not tolerate big antennas. On a 20m long wire antenna,  the radio has a lot of overloading on nearly all frequencies. With my old 5,50m vertical CB antenna, which is modified for shortwave reception,  there are only overloads on 15 MHz and 4MHz during daytime reception. In other words, if you want  to operate the R-1000, you do need a preselector.  But with short antennas, the R-1000 works without any problems.  Even weak stations, which could be heard with the NRD 525 on a 20m long wire, could also be received with the combination of the R-1000/AOR SA-7000. Very weak, but without overloading at least.  What is noticeable immediately,  is  the width of the filters which is far too wide.  But you can remedy that by switching an internal plug.  But then you will notice a whistling sound when you go through the  AM bands caused by interference.  No wonder then that there were and will be always modifications as far as the filter band width is concerned.  Another negative point is the high noise level of the NF-amplifier when you select the tone control. You can filter that out by using a DSP audio filter, e.g., the Timewave DSP-9.  A nice shortwave receiver, which is getting on in years, though.




Kenwood R-5000

This is not the first R-5000 which I own.  It is difficult to find a radio which works 100%.  If you buy a used R-5000, you have to make sure you buy one with the numeric key pad and the mode selector intact.  This is a major weak point of this receiver. Behind the key pad is a membrane switch  which after some time either oxidizes or simply wears off.  If this happens, several digits will show up instead of just one when you select a frequency on the pad. Also, the R-5000 becomes very hot when you power it with 230V. Bad for the electronics! But if you find a good R-5000, buy it and operate it with 12-14 V if possible because the reception quality is simply outstanding. With some patience and luck I was able to find a new one with the help of one of my colleagues.  This R-5000 works flawlessly. The numeric keys function properly and there are no other malfunctions.  To avoid over-heating, I installed a 12V connection. Thus I can operate the R-5000 without the internal power supply which is responsible for the excessive heat and the R-5000 stays within the normal temperature range.   For AM listeners  I recommend the installation of  the AM- 6KHz filter YK88A-1. It is very selective but hard to find.  As far as its reception quality is concerned, the R-5000 is on par with the NRD-525 but just sounds better.




Kneisner+Doering KWZ 30

The Kneisner+Doering  KWZ30 is not very well known. It was produced in Germany.  Professional shortwave receivers such as Rhode&Schwarz, Telefunken etc are or were manufactured in Germany.  The KWZ 30 is a DSP (Digital Signal Processing) receiver. One of the advantages of such a radio  is that e.g., the band width filters are not hardware, but software components. They have a much better quality than most hardware filters.  Additionally, DSP also controls the demodulation. Compared to analogue radios,  AM-reception is largely free of distortion. As you can see in the picture, there are only a few controls on the receiver and the radio reminds us of the AOR AR7030. All controls are in menus which are operated by a key pad. Luckily, however, the KWZ 30 has some "user key pads" F1-F4.  These can be programmed individually with any function. I for one like this kind of operation. The KWZ30 can also be controlled via PC. But because it is a fairly rare receiver, there are hardly any programs which could control the radio with the exception of RadioCom 6 by Bonito.  The KWZ 30 is not exactly nice to look at.  Its design is industrially functional but is very solidly built. What you notice positively right away, is the VFO.  It is solid, can be operated precisely and its flywheel effect can be controlled wonderfully.

How does the KWZ 30 sound?

What you notice immediately, is the radio's AM quality. Compared to other receivers and  thanks to DSP there are far fewer distortions. SSB reception is also very good. The radio has a nice bright sound and there are no digital artifacts. Luckily, the KWZ 30 is nothing like the NRD-545 DSP with its aggressive sound. I was very surprised by the radio's large signal rejection.  Compared to other high-end receivers, I did not notice any disturbances, although the receiver has no preselection, only a low pass filter at 32MHz. Super!!

You do not see a KWZ 30 every day. It is an absolute rarity. It almost had a follow-up model, the KWZ-50. Unfortunately,  it was very expensive and this may be the reason it did not find any buyers.  Shortly after the introduction of the KWZ-50, Mr. Kneisner, its developer, passed away.





Lowe HF-150

When it came out, the Lowe HF-150 caused a minor revolution. This small and powerful receiver impresses the hobbyist with its excellent performance. His almost Spartan design ( there are only a few controls) found many fans.  Taking into account that it is a portable radio, which can be operated with batteries,  the HF-150 offers features, which many table-top receivers do not have.  There are a fully fledged synchronous detector, SSB reception, excellent sensitivity on all bands and a an audio which is almost similar to a tube radio. There is one flaw, however: Its bad large signal rejection when using large antennas.  That is no surprise, though, because the radio does not have a preselector.  That was remedied by an external preselector, the PR-150. It was not exactly cheap, however,  but the PR-150 made it possible to operate the HF-150 with large antennas.  The reception quality almost reached a  semi-professional level. After a while, some hobbyists found out how to tune the HF-150 by simple means. With this modification,  the PR-150 became superfluous and the large signal rejection of the radio could be raises to an almost professional level. In short: It is a receiver with a minimalist operation and maxi-performance. The HF-150 shown in the picture has a special display light.




Lowe HF-225

The Lowe-225 looks very Spartan. The small number  of controls reflect Lowe's philosophy.  But the radio has very good reception qualities inside.  The sound and the reception are excellent.  In the picture, the receiver is shown with its new colors.  The Lowe HF-225 has no need to shy away from its younger brother, the AOR AR 7030, both of which were developed by John Thorpe. The audio is largely  the same.  Only the intelligibility is not as good as the AR 7030's. When comparing the large signal rejection of both receivers on a 20m long wire, both of them show the same performance, although the AR 7030 is said to be a lot better according to the tests which can be read in the journals. The AR 7030 shows noticeable interferences on 22 MHz - 24 MHz and on 27 MHz.  The HF-225 is much quieter on these frequencies. During the evening hours, however, you will notice a distinct noisy background.  Another complaint concerns the mechanical manufacturing of the receiver: It is built cheaply! In comparison, the HF-150 is built like a battle ship. The HF-225 can be recommended to fans of a Spartan design and operation.




Lowe HF-225 Europa

Thanks to Finnish DXers, the HF-225 changed into the "Europa" version. These DXers were not completely satisfied with the receiving qualities of the HF-225 and started to modify the HF-225. This modified version proved to be so good that Lowe agreed to produce it in series. Originally, this receiver was called "Finlandia" and later changed its name to HF-225 Europa. Unfortunately, only a small number was manufactured and so this receiver is rather rare.

The modification improved the large signal immunity and the selectivity by using narrower and better band width filters. In contrast to the normal HF-225, the "Europa" version came with a AMS/FM mother board and an external frequency keyboard. Additionally, there is a nice VFO made of black anodized aluminum. For my HF-225 Europa I also had a display and S-meter illumination added and a modified audio amplifier. This is supposed to improve the sound even more. Because I have owned the original version of the HF-225 several times, I can easily tell the differences between the normal version and the HF-225E.

Of course, I also compared the HF-225E with other receivers including the top notch Icom IC-R9500. Of course, you have to take into account that the HF-225E has been on the market for a couple of years but it does not have to shy away from modern receiving technology.  Using a cross loop antenna, the HF-225 was able to handle strong active antennas, whereas the normal HF-225 handled them with difficulty and  overload effects occurred repeatedly. The band width filters are narrower than those in the normal version. Their widths is 2.2 KHz, 3.5 KHz, 4.5KHz and 7 KHz, respectively. These filters improve the DX properties of the radio but the sound range is diminished somewhat. All of this can be compensated by the very effective tone control. The Kiwa-audio modification further improves the sound which becomes even clearer and more intelligible with a wider bass range. The sound of the HF-225 Europe is superior to the IC-9500 as long as there are no interferences. Except for the synchronous detector, which can eliminate fading and the typical AM crackling sound, the HF-225E (just like the HF-225) has no features to fight interferences. The sidebands cannot be selected and the detector loses synchronization rather quickly. This problem can be solved by using external audio filters. Regarding sensitivity, the HF-225E is on par with its competitors , especially on long- and medium wave and even is a little more sensitive than the IC-R9500.

In conclusion it can be said that the HF-225E is better than the HF-225. It can handle my active antennas without any problems. With the narrower filters, selectivity is noticeably better. Thanks to the Kiwa-modification, the HF-225E sounds even better and gives the listener a great deal of pleasure. A great radio, indeed.




Lowe HF-250

The HF-250 is completely made of aluminum and ruggedly constructed. On my 20m long wire antenna, the HF-250 almost impressed me. There were few 'ghost' stations and when there were any, there were very weak. As far as sound is concerned, the HF-250 is not on the same level as the HF-225, although it doesn't sound bad. There is a little more noise than on the HF-225.  The HF-250 has a synchronous detector and four selectable filter widths.  There is also a remote control included and the receiver can be controlled by a PC with its RS 232 connector on the back. It can also be operated with Radiocom 6 and other control programs.




Lowe HF-350

Actually, the HF-350 is no Lowe. Hidden in its case is the Palstar R30. It seems like Palstar followed Lowe's philosophy.  The operating concept is practically  identical with the Lowe receivers and is so simple that a manual is almost superfluous. Most of all: reception is very impressive!.  The large signal rejection is IP3+15dbm! During the evening hours, there were almost no 'ghost' stations to be heard on a 20m long wire antenna. The sound can be compared to the Lowe receiver, i.e.. very good! The HF-350 has 100 memories which can be scanned with the VFO.  The receiver can also be used as a portable because it can be powered with 10 AA batteries. The HF-350 can almost be seen as a reduced further stage of the HF-150




Palstar R30A

Palstar is an American producer of amateur radio equipment, such as antenna tuners, amplifiers, active antennas and shortwave receivers.  At the same time when Lowe, the well-known company with its excellent shortwave receivers, discontinued its production, the Palstar R30 appeared on the market.  The idea of operation of this receiver was the same as the Lowe receivers: Spartan. Few knobs and few functions on the one hand, very good reception quality on the other.  For a short time, Lowe sold Palstar radios under its own name. (cf. Lowe HF-350). The Palstar was in the same league as the HF-225.  The HF-225 sounded better, but the R30 had a better strong signal handling capability. Over the years, the R30 was optimized and was sold as R30C or R30CC.  The 'C' means that Collins IF-filters were used, so the 'CC' model had two Collins filters.  The R30 was very practical because it could also be used as a mobile receiver using 10 AA batteries. Inserting the batteries was not as easy, however. The R30 had to be opened, which over a longer period of time can lead to damage of the screws and the case.

Around 2008, the Palstar R30A appeared on the market.  The radio had undergone a slight change of design and the electronics had been altered a bit. But basically, the basic components had stayed the same and the tried and tested circuit concept was kept. Again, high-quality 5.5 kHz and 2.5kHz Collins IF-filters were used. The display lighting can be switched off to save power when the radio is used as a portable.  Unfortunately though, this good idea was not thought through to the end because the S-meter, which requires a lot more power, cannot be turned off. An excellent feature of the R30 is the 455kHz output on the back of the radio which makes it possible to connect the well-known and expensive Sherwood SE-3 synchronous detector and other accessories.

Basic data:
-- Frequency range: 100kHz - 30MHz
-- Modes: AM, LSB, USB
-- Band widths: 2.5kHz and 5.5kHz (mechanical Collins filters)
-- Tuning steps: SSB 20Hz to 100Hz SSB    100Hz to 500 Hz AM
-- 100kHz steps using the push button
-- AGC: Fast and Slow
-- 10dB attenuator
-- analogue, calibrated S-meter, illuminated
-- 100 memories selectable with the tuning knob or the +/- push buttons
--cbattery operation possible
-- 455 kHz IF-jack
-- Very good large signal handling capability (IP3+15dBm)

The R30A was compared to the ICOM IC-R75 because it is in the same price range.

In the long wave and medium wave range it is noticeably more sensitive than the IC-R75 and has a better selectivity in AM due to the excellent Collins filters and the crisper audio. On shortwave, the R30A is on par with the IC-R75. The good AGC is another asset.

The disadvantages of the R30A become noticeable when the frequency is interfered with. Only ECSS operation can cancel out nearby-channel interferences.  The IC-R75 has some features to cope with these problems, which the R30A does not offer. The R30A has no passband tuning or notch etc. Using my BigLoop, reception with the R30A was without any problems.  The radio could handle the occasionally high levels of S9+40dBm without any troubles. I couldn't notice any large signal interferences. Up to the 10m-band, the radio's performance was as good as the ICOM’s.  Regarding SSB reception, the R30A had to shed some feathers. The smallest tuning step is 20Hz, which is too coarse for digital modes. The smallest tuning step of the IC-R75 is 1 Hz. The intelligibility of both radios is the same, which shows that the Palstar R30A was made for speech signals.  Sensitivity decreased somewhat with higher frequencies. In the 10m band, the IC-R75 was clearly more sensitive due to its selectable pre-amplifier. Unfortunately, the headphone jack does not work in stereo, so an adapter had to be used every time.

The mechanical stability is good.  The case is powder-coated and can withstand smaller hits. If you want to use the good internal speaker of the radio,  you should not put the volume up too high, because then the case will start to clatter which seems to be typical of American-made receivers. Unfortunately, only a few receivers were produced. The Palstar R30A is one of them.  Because of its underlying philosophy, the radio is easy to operate but offers no signal processing. To have the same features of the IC-R75 you would have to use audio filters, e.g., Timewave DSP 59+. Taking all this into account, you come to the question of the radio's price tag. Directly from the producer, the R30A was 895.00 $. Today, this is a hefty price for such a simple radio. But it does have good receiving qualities.

When buying a used Palstar R30, R30C, R30CC or R30A, you should make sure that the tuning coder behind the tuning knob is working normally.  With used radios, the tuning coder is often defect. If this is the case, the frequency cannot be tuned correctly, jumps from frequency to frequency or cannot be tuned at all. This so called rotary encoder costs approx. 30$ at Palstar.

Written at 23.02.2015






Perseus SDR

If you hear or read the word 'Perseus', you can't help but think of the Greek myth. Perseus was the son of Zeus and Danae. He is known to have cut off Medusa's head.  But enough of Greek myth. By 'Perseus' I mean the new Software Defined Radio (SDR). By October 2007 word got around that this new SDR would soon  appear on the market. Now everybody is talking about it and the radio is on the table of many a SWL. What makes the Perseus so interesting?  First of all, 'Perseus' is an abbreviation: "Pretty-Excellent-Receiver for-Software-Eager-Unperceivable-Signals".


The Perseus in action on MAC.  It only works with boot camp. The Perseus does not run in a virtual environment!


The Perseus is a so called black box receiver,  i.e.,  a receiver which can only be controlled with a computer. This computer should have a good performance, otherwise the Perseus will not work satisfactorily. Computer from the good old DOS era  can confidently be discarded. Windows XP or Vista with 2.5. Dual Core CPU and a minimum of 512 MB RAM are required.

The frequency range is selectable from 0 - 40 MHz in AM,.AMS, CW, RTTY, USB, LSB, FM, DRM and User.

In the small window, the band filter widths can be selected freely from approx. 50Hz to 50KHz with the help of the mouse. The Perseus has a choice of either a waterfall or a spectrum display with a max. band width of 1600 KHz.  Starting with the software version 1.1.C, there is also a zoom function, so you can zoom in on the selected display to a few KHz.  A double click on the waterfall or spectrum display will change the selected frequency immediately.  The Perseus offers  freely variable band pass tuning and a super notch filter, whose blanked out area is selectable. The Perseus' software offers a  choice of three frequency lists and the name of the selected station is shown. However, the memory system of the Perseus is not really user friendly, it takes some computer knowledge to integrate these frequency lists.  There are other features which cannot be described here because it is beyond the scope of this article.  There are quite a few settings possible in the registry.

A real novelty is the recording of the frequency spectrum of up to 1600 KHz, so you don't have to stay up all night to wait for your program. Before going to bed, you switch on the record button and listen to the recording the next morning.  You can move freely in the recorded frequency spectrum:  you can select the mode,  add a notch filter etc. etc.  You almost have the same options when listening to the radio 'live'. As mentioned above, the Perseus only works with a newer PC.  It barely worked on my old PC with 1.8 GHz and 768 RAM. But as soon as you used DRM or other programs, there were skips. As I wanted to assemble a new PC anyway, the problem took care of itself.  My new PC has a Dual Core2@3GHz, overclocked to 3.6GHz and with 3GB there are enough main memories.  Thus the Perseus runs without any problems and is ready for some comments on its receiving qualities. When the discussions about the Perseus started on the internet and its technical data were published, I was doubtful , whether the radio would live up to its promises.  I think, I was not the only one, who was skeptical, but I bought a Perseus anyway. If you have some knowledge of shortwave reception and receivers, you hear right away, whether a radio lives up to its reputation.

The Perseus keeps its promises!!

Reception is very convincing. As far as intelligibility is concerned, there are  not many radios on par with the Perseus.  This is particularly true in respect to  signal processing with its almost continuously variable filters, the very flexible BPT and the excellent notch filter. In addition, the sound of the soundcard software can be controlled with an equalizer.  The Perseus has a somewhat harsh hissing sound, however, which can become a little bothersome when using headphones over a longer period of time. As far as I know, there is no hardware receiver which offers such flexibility of signal processing. As regards intelligibility  and flexibility,  the Perseus beats almost every other receiver. Also its large-signal immunity is very good. I couldn't notice any disturbances at the time of writing. Another SDR, the CiaoRadio, has the same reception qualities but its large signal immunity was bad. In the evenings,  there  regularly  was a lot of overmodulation. The Perseus can handle high-quality antennas.  I connected it to the ALA1530S+ and a 20m-wire antenna and there wasn't any overmodulation. Excellent!!

I compared the receiver with the DSP receiver Kneisner & Doering KWZ30.  Generally, both receivers had the same reception qualities.  But the KWZ 30 sounded  a little better  because it has a wider audio frequency range.  With very weak signals, however, the intelligibility of the Perseus is a little better.  But the Perseus has its disadvantages as well! It is very power-hungry! An old PC will not be able to handle the Perseus. The other disadvantage: You will be sitting in front of a computer to listen to short wave programs with the internet with its Perseus related  forums running at the same time. You will have a hard time to break free from the PC!  Danger of addiction!!

In the mean time, after some software updates, DRM works well, too. Fortunately, the developer, Nico Palermo,  improves the radio continuously and he is offering a memory bank with 600 memories making external memories superfluous.

For 849 € you will get a radio with a performance of considerably more expensive receivers.

On the page '"Comparisons" you will find comparisons of reception.

The current software can be downloaded >here<

Controlling software and other programs for the Perseus can be found >here<



FM+ Microtelecom

Although the FM+ is not about shortwave in the strictest sense, I would like to introduce it, nonetheless. The FM+ is a FM converter which was developed to be operated together with the Perseus SDR and so the excellent features of the Perseus can also be used for the FM-band. The FM+ receives the FM band from 87.5 KHz - 108 MHz and is entirely controlled ( how could be otherwise?) by PC. The FM software (GUI) is very similar to the one of the Perseus with adaptions for the FM band. The broad band spectrum is very useful and comes with a range of 1600 KHz and a continuously adjustable band width filter. The RDS-function, which makes the immediate identification of a station possible,  has to be mentioned as well.  How does the FM+ sound? In short: Excellent!! With good head phones or good loudspeakers the Microtelecom receiving system renders a breathtaking sound, when "Stereo Wide" is on. The sound is wonderfully clear when listening to strong stations. But the FM+ is not only good for armchair listening. It is very well suited for FM-DX. With its sharp filters, (adjustable from approx. 22KHz - 400KHz), weak stations can be made audible. For the first time, I could receive stations in my area, which I had never heard from.



 FM+ in Action (HD Video)

On my Diamond DA-130 (8 m above ground), the large signal rejection was excellent .

If you own a Perseus SDR and there is nothing going on shortwave, you should have a closer look at the FM+.  You can lean back and enjoy FM in "Stereo-Wide" or do some FM-Dxing. Unfortunately, the fun is not really cheap. You will have to put 299EUR on the counter.

Here you can find audio comparisons with the Reuter DR50B.

Many thanks to SSB Electronic for putting the FM+ at my disposal.

Here are some technical data : SSB Electronic product page

posted 25.08.2012



RadioJet 1102S

Even before its introduction to the market shortly before Christmas 2011, there were wild speculations, debates and even fights. Nobody knew exactly, what sort of radio would appear on the market. Due to faulty parts, production and shipping were delayed and additionally, there was a shortness of supply which gave even more reasons for speculations. All in all, it was an unsuccessful start for the RadioJet 1102. In the mean time, the receivers have been shipped and speculations ended. Bonito was friendly enough to put a RadioJet at my disposal for testing Thank you vey much! What sort of radio is the RadioJet? Well, it is no normal SDR. It is an analogue receiver with a soundcard in the same case. The signals are digitized and sent to the PC. With  an extensive software the signal can then be decoded, analyzed before it is sent to the loudspeaker. There is some getting  used to it because of the enormous capabilities of the software. During this learning curve, the manual will become a good friend of yours because you will get to know functions which you didn't know before. Reception range is from 40 KHz to 30MHz in AM, SSB, CW, FM, WFM and DRM.  There is also room for external frequency converters to enhance the reception range.  By the way, DRM works without external software. The software has functions which are unrivalled in its class. An interesting new function is the RX/DX channel. This function makes it possible to enhance sensitivity and decrease noise at the same time. Of course, this results in a slight loss of large signal immunity but it makes listening to weak signal possible. This feature only works in a quiet environment. Another handy feature: The selected station is shown in the spectrum next to the signal peak and appears on a world map with the borderline of day/night being shown. Another unique feature is the 'filter manipulator'. You can create your own bandwidths and save them. Its is also possible to draw any number of notch filters within these band width filters. The steepness of the filters can be adjusted as well. The spectrum scope can have the form of a waterfall and even 3D with many possibilities of adjusting the scope. Then there are the software window and the extensive frequency bank which can be edited, of course. I will do without a further list of other functions and possibilities. That would be far beyond the scope of this short presentation. Please, consult the manual on Bonito's website. Everything is described  there in detail with pictures of the functions.

The most important question: How is reception?

At the time of writing (March 28, 2012), I am comparing the RadioJet with the Perseus SDR and have been able to  gather a few hours of experience with the RadioJet. This is absolutely vital because the RadioJet is very demanding regarding its software. After adjusting everything the way it is supposed to be,  both radios are alike as far as the rendering of the signals is concerned. There were no problems with strong signals,  not even with the DX-channel. As regards sensitivity, both radios are on par. Contrary to the technical data,  the Perseus is a tiny bit more sensitive and has a little less noise. This article is meant to be short presentation of the RadioJet 1102. On the page " reception samples", you can hear audio samples of both radios. As a preliminary result you can say that the RadioJet is a top class receiver with an extraordinary software. With a current price of 600 € it is not cheap but worth it.

Please note: Just with other SDRs, the software of the RadioJet requires extensive programming.  Naturally, there are still minor bugs which are gotten rid of by Bonito. The software will be continuously improved.

posted 24.04.2012


RadioJet in Action (HD Video)


RadioJet 1102S >> News

Since the first test many changes and improvements of the RadioJet software have been made. So much has been done that mentioning everything would be too much of a good thing. But I would like to mention some improvements, nonetheless. It has always been a point of critique that the frequency spectrum of the RadioJet is only 24 KHz wide. Now, the software makes it possible to incorporate a second SDR with a large broadband spectrum. This way, you can make use of the RadioJet as an 'audio receiver' and the signal of the second SDR is shown on the broadband spectrum. This broadband spectrum can be adjusted, too. If you already own a RadioJet you can buy ,e.g., the FiFi-SDR resulting in an enlarged broad band width of up to 192 KHz. Other SSDRs are supported as well, e.g., the Perseus. You then will have a 1600 KHz wide- spectrum. Please, consult the Bonito project page for further details. The new noise blanker and the new selection of the modes should also be mentioned. The reception quality was also improved and is now on par with the Perseus and even better in case of weak stations.

Below are a few HD videos showing the RadioJet in Action. The best  open in YouTube for HD.




Reuter RDR50B

It took some time for the RDR50B, which had been promised to me, to find its way into my home. The reasons were supply bottlenecks of electronic parts and a lack of available test units. However, Mr. Reuter kept his promise. Now the RDR50B with an additional FM-module has been on my table for three weeks. The RDR50B functions almost exactly like its bigger brother, the RDR54. The RDR54 is built in a modular concept; it has only one big main board on which you can attach the FM- and the transmitter modules. The biggest difference to the RDR54 is its large touch screen. Every function can be controlled with a touch of your finger, almost like an iPad! Luckily, the radio has a sensitive VFO made of stainless steel for frequency selection. The special feature of all of the Reuter-radios is their mechanical work, no plastic parts were used. The case is made of milled aluminum and anodized in black. In this respect, the Reuter radios are in their own league. Absolute top quality!
If you are familiar with RDRs, the operation of the RDR50B is easy. Compared with the RDR54, everything can now be controlled faster because of the touch screen. The click area is a little too small at times. You have to aim very accurately to get at some functions. But that is all a matter of getting used to it. After some hours, everything went smoothly.
The RDR50B has the following modes and options for reception improvements:
-SYNC automatic detection of the carrier with selectable sidebands (like AM-synchronous)*
-EUSB - for signals starting at 0 Hz*
-SBCW-automatic switching of the side bands at 10 MHz
-IFIQ direct readout of the received signals on an intermediate frequency
-BAIQ direct readout of the received signals in a base band
-63 memories, which save all the parameters of the frequency. Unfortunately, the memories are not alphanumeric for the time being because of technical reasons.
-The bandwidth filters can be adjusted in 40 Hz steps from 10 Hz - 10 KHz and in 80 Hz steps from 10 KHz - 20 KHz.
-Band pass tuning (IF shift)
-manual notch filter
-noise blanker
-DNR (Digital Noise Reduction)
Thus, the RDR50B is ready for almost every situation.
Regarding the most important criteria, such as low noise, intelligibility, selectivity and large signal immunity, the RDR50B is top class! Compared to my other radios, the RDR50B was almost always just as good. It especially showed its strength when trying to receive weak stations. With such low noise, it was almost always better than the other receivers. But where there is light, there is also shadow. Because of its special way of working, the RDR50B sounds a little tinny in its modulation. It sounds digital and artificial. But these are the only weak points of the radio.
Just like the RDR54, the RDR50B is a SDR (Software Defined Radio) and depends on a PC. Except when downloading software updates.
The built in FM- module is in its own class. It has a sound and selectivity, which are unrivalled in its class. I will put audio comparisons on the internet, which can be found here….
As to the scope of the functions of the RDR50B, I refer to the webpage of the manufacturer, Reuter Electronics. That would be beyond the scope of this article.
If you are looking for high quality manufacturing and low noise reception, the RDR50B could be the right radio for you.
*For the special modes, please consult the manual of the RDR50B.


The RDR50B in Action (HD Video) First on FM, then on SW.




RFSpace NetSDR+

In Europe, the NetSDR by the American manufacturer RF Space is hard to find. Since early 2016 an extended version, the NetSDR+, has been on the market. Besides slightly improved technical features, the NetSDR+ sports a downconverter which extends the frequency range to max. 1700 MHz I was sent the NetSDR+ directly from RFSpace to compare it to well-known SDRs like Perseus, Elad and the new S9-C Rabbit SDR.

The RFSpace Company, run by Pieter Ibelings, employs a staff of three that is exclusively involved in the development and testing of the products. The radios are then built by a local manufacturer and are 100% developed and manufactured in the USA.  RFSpace has been active in the field oft software defined radios for a couple of years.  Their first product was the SDR.14.

The NetSDR+ comes in a nice white and blue box. Included is a two-meter long Ethernet cable, a CD with the operating program "SpectraVue" and a configuration program for the Ethernet connection. The radio also comes with a 5V switching power supply. Fortunately, I have high-quality, analogue 5V power supply by Statron and so I can leave the switching power supply in its box.  We SWLs know that this type of power supply can cause heavy interferences.  But at least they do include a power supply which can be used in an emergency. Not every switching power supply cause trouble.


Blockdiagram from NetSDR+

Basic information of the NetSDR+:
-- sampling rate: 80 MHz
-- 16bit A/D converter
-- IQ bandwidth: 1600 kHz
-- Frequency range: 9 kHz - 32 MHz and 40MHz-1700 MHz with a downconverter (option is included)
-- Modes: AM, SAM, LSB, USB, WUSB, CW-L, CW-U, NFM, WFM ( modes depend on the software; the ones mentioned here are supported by SpectraVue)
-- 4 selectable attenuators (0/-10/-20/-30dB
-- Preselector with 10 band passes and 34 MHz low pass filter
-- OCXO extremely noise free, temperature compensated oscillator (installed)
-- IP 3+ 34dBm
-- 1 BNC antenna jack
-- BNC jack for external reference signal
-- BNC IF jack
-- RJ45 LAN jack for PC connection or network
-- USB connector for setup (optional)
-- AUX jack for Stereo (for later add-ons)
-- RS232 jack for the control of external devices
-- built-in loudspeaker for IP address announcement
-- 5V operating voltage
-- stable, black steel chassis
-- Dimensions: 228x38x180mm (BxHxD)

The technical data make clear that the NetSDR+ is a high-quality receiver. It has a preselector with 10 band passes and two low pass filters. In addition, the radio has a 16bit ADC (Analogue/Digital converter) with a 80 MHz sampling rate.  All of this raises the level of expectation!

The build quality meets all wishes.  Matt black painted sheet steel chassis and well finished circuit boards are a joy to look at. For a better view of the preselector, the downconverter and the OCXO were removed.


Since early 2016, the NetSDR+ comes with a downconverter which expands the receiving range considerably.  Originally, the receiving range is from 40 - 700 MHz with a small modification described by the manufacturer reception up to 1700 MHz becomes possible.  You have to buy a short pigtail "U.FL/UMCC to SMA" in order to connect the downconverter directly to the antenna because originally the same antenna jack is used for shortwave and VHF/UHF.


My radio was supplied with a temperature-compensated and highly-stable (+/- 1ppm) quartz oscillator (OCXO). This option also guarantees an extremely low phase noise of -168dBc/Hz.

Initial operation

After connecting everything, the network configuration has to be established because the NetSDR+ does not send the data via a USB-cable but via a network cable. The advantage is that much larger data volumes can be sent. The program "SDRNetSetup" provides an IP-address, should that be necessary.  Otherwise you start the supplied software "SpectraVue“ and use the simplified network configuration because normally, the NetSDR+ pops up immediately after starting the program.  Possibly, the firewall or the router will block communication.  In this case you have to open the appropriate ports.  The installation and configuration took about five minutes.

Compatible control programs


"SpectraVue" is the standard program for the NetSDR+. This program should be installed because it is the only way to install firmware updates for the NetSDR+. The manual operation of the preselector is only possible with "SpectraVue".  This makes sense if you want to test the preselector or do reception tests. The GUI of SpectraVue has not been changed for years. This makes the program look a bit old-fashioned. It has a definite Windows 98 look. Technically, SpectraVue has a lot of functions which are hidden in the menu. FM-reception in stereo with RDS is supported but unfortunately, the bandwidth in WFM cannot be changed. The operation of the bandwidth control for longwave-, medium wave-, and shortwave reception is measly and cumbersome.  You cannot integrate frequency lists, e.g., Eibi, Aoki etc. There are only 20 memories. An important feature, a frequency input window, is missing altogether. But basically, reception with SpectraVue leaves a good impression.  The audio is very clear.


SDRSharp is a freeware control program for many SDRs and also for the NetSDR+. This program has many functions to improve reception. There are many controls for practically any function. FM-reception in stereo with selectable bandwidths and RDS are included. Frequency lists cannot be imported but you can compile your own list and have the station's name be shown in the spectrum.  Unfortunately, AM synchronous reception is not possible and there is no S-meter readily visible. But there is a -dBm bar display on the right side of the spectrum which is hardly visible, however.  There is no frequency input window. You can only enter the frequency with a keyboard by putting the mouse pointer to the appropriate digit in the frequency display. The noise filter, the noise blanker and AGC are widely adjustable and work very well. Unfortunately, the SNR of SDRSharp is not very good. With other programs, very weak signals could be heard a lot better.


SdrDx offers many interesting programs.  But it is totally confusing. There are more than 100 buttons on the GUI which can be selected. In spite of the many functions, frequency lists cannot be included. There is no frequency input window, either. But FM reception in stereo with RDS works very well.  Since this program is so confusing, I did not spend much time on it.  SdrDx is based on the "CuteSdr" program.


CuteSdr has almost the same design as SpectraVue with fewer functions. It is a basics-only program which has good bandwidth controls and a very good audio.

SDR-Console V2

My favorite is the SDR-Console.  It leaves nothing to be desired. Only the preselector of the NetSDR+ cannot be controlled manually but almost any other function is user-selectable. But not only that: this program makes everything possible that the NetSDR+ has to offer. The only disadvantage of the program is also its advantage. There are many features in this program which have to be discovered and understood. It takes some time to get used to this program.  As the only program it offers two waterfalls. In the lower spectrum/waterfall you can see the selected IQ-bandwidth. It can be displayed in many ranges up to max. 2 MHz. The upper spectrum/waterfall is the reception and control window. The red bar at the bottom shows the maximum range of the reception window.  It would be beyond the scope of this article to describe all functions. SDR- Console is the most complete SDR program and the best. That is really great: It's free!

SDR-Console V3 beta

Version 3 of SDR console is the successor program and is still in the middle of its development. It does not yet have all the functions of the V 2 but it is on its way. It works very well with the NetSDR+. FM reception with RDS functions well, too.

Like all other SDRs, the NetSDR+ can also be controlled via the internet.  You have to download and install the NetSDR-Server software. After that it can be operated with the same clients as the Cloud-IQ.



Reception with the NetSDR+

I have owned the NetSDR+ since early 2016. In the meantime I could become familiar with the radio and compare it to other SDRs. Of all the programs mentioned above, there was one which was the most convincing: SDR-Console.  In my view, the NetSDR+ works best with this program and therefore, I made all comparisons with SDR-Console.

As reference radios I used the Perseus, ELAD FDM-DUOr and the brand-new S9-C Rabbit SDR.  All in all, the NetSDR+ beats all other radios; sometimes more, sometimes less. The ELAD FDM-DUOr and the S9-Rabbit SDR came closest to the NetSDR+.  The DUOr is practically in the same league as the NetSDR+.  There were no noticeable differences regarding reception. Outside the band passes, the DUOr suffered repeatedly from "clipping".  The S9-C showed the same performance. Its weak point was the reception in the VLF/LW range.  Here the NetSDR+ was definitely better.  The Perseus came in as number four. Its sensitivity which becomes worse with increasing frequency and the lack of a downconverter made the Perseus look (a little) old-fashioned. 


The NetSDR+ is a high-quality SDR of its own league. Together with the SDR-Console it can hardly be beat.  But you do need a powerful PC or notebook.




RFSpace Cloud-IQ

Almost still hot from the factory, the Cloud-IQ by RFSpace is on my table. Not directly, however, because it was  the WIMO company from Germany which  put the receiver at my disposal for the first tests in Europe. After a few e-mails with Ekki (DF4OR),  the section manager for receivers, I was sent the brand-new Cloud-IQ.

Just like its preceding model, the SDR-IQ, the Cloud IQ is an inconspicuously small box with a red rim. It barely weighs 300g and its size is 101mmx122mmx30mm (width x depth x height) and is made of anodized aluminum. Included are:  a 5V external power adapter with an adapter for Europe, a two-meter long RJ 45 Ethernet cable and a power cable with a barrel connector on a USB plug for a direct connection to the PC. There is a CD with the software as well. Unfortunately, so far RFSpace has not realized that switching power supplies can cause noise on long-, medium-, and shortwave.It would have been nice, if a SMA/BNC adapter was included because the Cloud-IQ has SMA- connectors. Among amateur radio operators and SWLs, the SMA norm is not very common. You will have to buy an adapter beforehand, if you want to use the receiver right away.


Blockdiagram from Cloud-IQ

The most prominent features:
Sampling rate: 122.88 MHz 0 9Khz - 56 MHz (direct sampling)
-- 14 bit A/D converter
-- Frequency range; 9KHz - 56 MHz
-- Modes: AM, SAM, LSB, USB, WUSB, CW-L, CW-U, NFM, WFM (modes depend on software. The ones mentioned here are from SpectraVue)
-- Selectable attenuators: 0/-10/-20/-30dB
-- 2MHz switchable  high pass filter
-- 60MHz low pass filter
- -Broadband spectrum 56 MHz wide (with demodulation up to 10MHz)
-- TXCO, temperature compensated oscillator
-- 2 SMA antenna connectors
-- RF45 LAN- connector for connecting the PC or net work
-- built-in remote server
-- 5V operating voltage
-- RS232 connector for controlling external devices
-- solid, black case made of anodized aluminum.

The Cloud-IQ has its name not without a reason. It can be operated in two different ways: Either in the "Local-Mode" or in the "Cloud-Mode":

"Local mode" means that the receiver is directly connected to a local network or directly to the PC. This operating mode offers reception with all functions, full band width and full resolution of the spectrum.

In the "Cloud-Mode", the radio can be operated remotely at a different location without a computer. It only has to be connected to a router. In order to make the data transfer more stable, the amount of data is reduced in this mode, which means that the band width and the resolution are smaller. RFSpace offers a client-software at no extra charge which is available for three operating systems: Windows, OSX and Android. You can run Android on an Android-pad or on an Android smartphone.

On the included CD is the program SpectraVue which supports all functions in the "Local Mode". The three remote client-applications for Windows, OSX and Android are also on this CD. Additionally, you will find the configuration program for the remote operation of the Cloud-IQ. Last but not least there are the manuals for all these programs.

Program Installation

First, you should install the configuration software "Cloud Setup" for the Cloud-IQ. There were no problems installing it on Windows 8.1 and Windows 10. A small hint: Install all programs as "Administrator" which will avoid problems that might occur with the administrator rights. After that you connect the Cloud-IQ to the power supply, to the PC or to the router. Then you start the configuration software and look for the Cloud-IQ with "Find SDRs". Normally, it will be found at once. With a double click on the selected SDR, you reach the configuration page for the Cloud-IQ. There you select the IQ-mode for local operation and you close the window with "OK". If you want to use a router, you may  have to modify the port forwarding to activate port 50000. In the configuration window, you can also make other settings. In case you want to make your SDR accessible for the public, you can enter a time limit.

If you want to limit access to a group of people, you will have to choose a password. The settings of the IP-addresses are important, of course. All SDRs, which are available online, are listed on the web page "RFSpace SDR's on the Web."

The control program “SpectraVue” is easily installed as well. Because it is compatible with all RFSpace SDRs, you have to select the Cloud-IQ after starting the program. After that, SpectraVue has to find the Cloud-IQ, so you click the button ‘Find’ in the network setup. Now you can start at last. The installation took approx. 10 minutes including the configuration of the router and the Cloud-IQ. Not every router has to be configured, though. With my present router “Netgear WNDR3700” the port forwarding had be configured.

At first glance, the SpectraVue software looks Spartan. Many features are adjusted in the menus. Unfortunately, there is no frequency input mask. You can only select the frequency via the keypad by putting the mouse arrow above the frequency display. This is a little  unusual. The frequency can be changed with the mouse wheel by putting the mouse arrow in the spectrum. You can adjust the tuning steps in the menu. You can either tune continuously or only in the visible spectrum which is activated by clicking the button “Center Frequency-Ins.” The most important controls, such as mode selection, band width selection  etc are in the lower right corner in the program window, which is a little small, though. The menu for the selection of the AGC, noise blanker etc. can be accessed by clicking the “Set up” button. The most important parameters for the spectrum can be selected on the left side of the program window. With the function “Auto Scale” you  adjust the spectrum, the waterfall and the levels. Under the frequency display is the zoom function “Span” for the spectrum. With this function you can zoom in and out in selectable steps. SpectraVue offers 20 memories which can be selected with the button “Memory Channels” next to the span indicator. These can be edited in many ways. There are other selections for the pan adapter function, recordings and other spectrum settings. It would be beyond the scope of this article to discuss all of these.

Unfortunately, SpectraVue does not have some functions which a SDR program of the latest generation should have. SWLs will miss the inclusion of frequency lists like Eibi or Aoki. There is no notch filter, noise suppression, passband tuning and no DRM mode. In AM-synchronous mode, you cannot select the side bands separately, either. Another program, which works with the Cloud-IQ perfectly, is CuteSDR. SDR-Radio and HDSDR will be compatible soon. (September 2015).



Reception with the Cloud-IQ and SpectraVue

With a click on “Start” or on the F12 button, you start the Cloud-IQ. The first impression is always the most important one. And it was good! But let’s start at the beginning. The reference radio was the Perseus SDR. This radio also has a 14bit ADC (Analogue/Digital Converter) Both radios were operated with the supplied software. As reception antenna I used the NTi ML200, which renders the strongest signals. But I also used the NTi MegActiv and the Fenu-CrossLoop/RLA4B antennas.

Let's start at 23.4 KHz where the German Navy station DH038 transmits. Both radios had the same signal strength.  Unfortunately, this frequency range is interfered by a robotic lawn mower as can be seen in the spectrum. Antenna: ML200  

At 147.3Khz where the DWD (German Weather Service) transmits, there are practically no differences between the two receivers as far as signal strength is concerned. Antenna: ML200

In order for you to be able to make your own judgment, I recorded some reception comparisons and commented upon them. There might be differences, of course, between your and my auditory impression.

The recordings have two sections:

Sec. 0 - 10 > Cloud-IQ
Sec. 10 - 20 > Perseus
As always I recommend the use of headphones.

After DLF (Deutschlandfunk) has discontinued the use of 153 KHz, the Rumanian station Antena Satelor can be received well. As you can hear in the audio sample, the robotic lawn mower is audible and disturbs the signal. It has to be mentioned that the noiseblanker of the Perseus filters out the interference a lot better. On the other hand, the signal from the Cloud-IQ is a little better. Redeption was in AM-synchronous and 9KHz band width. Antenna: NTi MegActiv.


Europe 1 on 183 KHz renders a S9+30dB signal on both receivers. Of course, differences are small. The Cloud-IQ has a  slighter brighter and less distorted signal than the Perseus. Recdeption in AM-synchronous and 9KHz bandwidth. Antenna: NTi MegActiv.


DLF (Deutschlandfunk) on 549 KHz. Here the Cloud-IQ has clearly the upper band with a clean signal. The Perseus is noticeably less clear with local interferences. Both SDRs had their noise blankers on. The music in the background comes from UR1 from Ukraine. Reception in AM-synchronous and 9 KHz band width. Antenna: NTiMegActiv.


Laser Hot Hits on 4025 KHz. In my opinion, you can see here the weaknesses of both receivers. The noiseblanker of the Cloud-IQ badly filters out the local interferences and sometimes not at all. There is a high level of background noise in the Perseus. The crackling of the Cloud-IQ  disturbs the signal to a higher degree, though. Reception in AMS and 7 KHz bandwidth. Antenna: ML200


Radio Rebelde from Cuba on 5025 KHz. The first station I listen to in the morning before work. A real wake up call with salsa music! A little distorted today on both receivers. Receptiion in AMS and 10KHz band width. Antenna: ML200


RAF Volmet, the Royal Air Force with weather reports on 5450 KHz. Both receives render almost identical signals. Reception in USB and 2.8 KHz band width. Antenna: ML 200


A short stop on 6070 KHz with the program of the DARC. The signal is relatively strong but al little distorted from both radios. They sound fairly similar. With both radios you will notice the bane of the shortwave, namely PLC (Power line Connection). Reception in AM-synchronous and 12 KHz band width. Antenna: ML200


The 40m ham radio band: Here the signal of the Cloud-IQ is more pleasant. It has less background noise than the signal rendered by the Perseus. Reception in LSB and 3KHz bandwidth. Antenna: ML200


A short visit at the fishermen who often chatter on 8250KHz. The Cloud-IQ has a low noise signal which is disturbed, however, by some kind of crackling noise. The Perseus does not have this noise, but there is some hiss to be noticed. Reception in USB and 3 KHz band width. Antenna: ML200


Radio Revival on 9405 KHz in USB. A pirate station from Sweden. Both SDR sound very similar, with a crackling sound in the background in the case of the Cloud-IQ. With the Perseus, there is a slight hiss in the background. Reception in USB and 3.3.KHz band width. Antenna: ML200


A narrow signal for some change! On 10355 KHz, there is a channel marker of the Israeli navy. Both SDRs render the signal equally well. Reception in CW and 100 Hz band width. Antenna: ML200


On 11580 KHz Brother Stair from Florida/USA can be heard. At the time of reception, there was a very weak signal and a challenge for both receivers. The Cloud-IQ renders the signal a little better because there is less background noise. Reception in AMS and 6.7KHz band width. Antenna: Fenu-CrossLoop/RLA4B


Manila/Philippines on 12120 KHz. Identical rendering of the signals. Reception in AMS and 7.2 KHz band width. Antenna: Fenu-CrossLoop/RLA4B


Here again something from fishing! On a 13343 KHz you can hear a Portuguese fisherman, who is talking to another vessel about his catch. Generally, the Perseus seems to have more of a background hiss in SSB. Reception in USB and 2.8. KHz band width. Antenna: ML200


On 13955 a pirate station in an undetermined mode. Best in LSB. No difference in reception. Reception in LSB and 2.8 KHz band width. Antenna: NTi MegActiv


HamRadio in the 20m-band on 14275 KHZ. The Cloud-IQ had a clear edge. Reception in USB and width. Antenna: NTiMegActiv


The time signal from Canada on 14670 KHZ. The signal was very weak and had to be amplified a bit with the recording program in order to hear something at all. The Cloud-IQ seemed to be bit more sensitive. Reception in USB and 2.8KHz band width. Antenna: NTiMegActiv


Sound of Hope from Taiwan on 15800 KHz. A little more noise with the Cloud-IQ. Reception in AMS and 7.2KHz band width. Antenna:ML200


Radio France International on 17615KHz with a weak signal. Both SDRs with identical reception. Reception in AMS and 7.2 KHZ band width. Antenna: Fenu-CrossLoop/RLA4B


16m-band ham radio. Intelligibility of both signals identical. More background noise with the Perseus. Reception in USB and 2.8KHz bandwidth. Antenna. ML200


World Harvest Radio on 21600 KHz. Practically identical audio. Reception in AMS and 7.2KHz band width. Antenna: ML200.



Reception in the 6m-band with relatively poor conditions. The signal of the CW-beacon HB9SIX from Säntis (CH) can be heard well, but weak. Reception in CW and 300Hz bandwidth. Antenna: ML200.


Remote operation with the Windows Remote-Client

A really fantastic option and one which comes at no extra charge is RFSpace's Remote Client for Windows, OSX and Android. A remote client is a software, which allows the remote operation of a SDR via the internet or the local network. You don't have to be present at your PC anymore to listen to shortwave programs. You can do it leisurely from your sofa in the living room.

During this test, I used the Windows- and the Androids clients. Unfortunately, I did not have OSX at my disposal. The Windows Remote RemoteSDRClient can just as easily be installed as SpectraVue. You start the client with a double click on the appropriate icon. It will try to access the internet with the Windows firewall warning that access is blocked. Of course, you have to allow access, otherwise the client will not work.  The next step is clicking on "Find SDRs" in the upper left corner. A window will open where you can see which RFSpace-SDRs are available worldwide. You choose one by double clicking the appropriate entry. Then you push "Start" and you should hear something.

In order to avoid interruptions, the amount of data was reduced and so there is a limited spectrum and resolution, which makes sense. Data transfer via the internet or WLan can be interrupted, no matter how advanced the technology has become in the mean time.

All important modes are available, such as selectable band widths up to 7.8 KHz depending on the mode. With the Windows client, interesting opportunities are available which SpectraVue does not have, e.g., a built-in decoder which shows the decoded signals. You select the decoder by choosing the "DIG" mode. The spectrum can be adjusted between 1 KHZ and 10 MHz with constant demodulation of the signal.

To receive acceptable audio, you should set the "AGC Threshold" back to approx. -80dB. resulting in less hiss. I recommend to reduce "RF-Gain" to -10dB; then there will be less "ADC Clipping". It all depends on the connected antenna, of course.

And because it's free, here is the link for the download:


Remote operation with the Android-Client

The Remote-Client for Android is outstanding. Listening to shortwave from your own sofa in really good quality! It works very similar to the Windows-Client, but comes without the PSK-Decoder. You can adjust the frequency by swiping on the screen. By swiping on the waterfall you can change the frequency in 500Hz steps in AM. Swiping on the spectrum will change the frequency slowly also in 500 Hz steps, which makes fine-tuning easy. IN SSB, the steps are 100 Hz. In the upper right corner, there are two arrows for frequency selection.  If you want to change the frequency in MHz-steps, you touch the MHz digit in the frequency display, which turns red.  Then you simply touch one of the arrow buttons for frequency tuning in MHz- steps. With "Auto" button you can adjust the level of the spectrum. In the menu you can select band width, mode and other features.

I could tell you much more,  but it's best for you to try it yourself. It is free, after all.

Here you can download the Remote-Client for Android. SDRAnywhere



The RFSpace Cloud-IQ really surprised me and positively at that. After intensive tests and comparisons, I couldn't notice any clipping effects when SpectraVue was used, despite the fact that the radio has no pre-selection. The clipping indicator often lit up but there were no overdrive effects. When the clipping indicator lit up, in most cases it was because of the near-by pasture fences which are not more than 20m away from the antennas. That makes for strong electrical impulses. In the evenings with the reception levels rising, the clipping indicator lit up at times, especially on the lower frequencies. But that was only the case when I used the NTi ML200 antenna. Because of its size, this antenna renders big signals which are too much for the ADC of the Cloud-IQ, but even then there were no overdrive effects. Although the Cloud-IQ has only a high- and low pass filter, it can tolerate a high signal level. As far as reception quality is concerned, the receiver is on par with the Perseus.

The program SpectraVue requires some getting used to, maybe more than other programs. But once you have checked out all functions and understood them, SpectraVue turns out to be a really good control program. With the correct configuration, SpectraVue renders a good and intelligible sound and is well suited for DXing. But there are some important features missing which a modern SDR program should have. The noise blanker could be improved, because the interferences from the pasture fence were only partially filtered out.

The Remote-Clients worked very well. Especially the Android Client is fantastic and I liked it very much. But you have to make some compromises regarding the functions, but that is really of no consequence. Just give it a try.

The RFSpaceCloud-IQ is a welcome addition to the SDR market.  In the same price range as the Perseus SDR,  it renders absolutely the same signals and with the Remote Clients access to RFSpace-SDRs worldwide.

Many thanks to the WIMO company for putting the Cloud-IQ at my disposal 

Cloud-IQ product page:

WiMo home page:

posted 4.09.2015





During the past few years, the trend has been more and more toward software defined radios (SDR). Why is that? Well, in our computerized age, more and more jobs are done with the help of a PC. So it stands to reason to have hobby-related applications done by a PC as well. As far as listening to the radio is concerned, there are some advantages which we cannot do without any more.  Almost all functions, which in the past were done by hardware, are done now with computer software. You don't need hardware radios for an excellent reception of shortwave.  But still these have their right to exist because not every listener likes sitting in front of the computer all the time and would like to have a few buttons to turn.

That is the reason why I had the SDR-IQ by RFSpace sent to me from the USA.  A small nice box, solidly built, is now on my table. There isn't much to connect. A USB-cable, the antenna and that is all. The power is supplied by the USB port. The installation is without any problems. The SDR-IQ comes with a CD which contains the program "SpectraVue", which is an easy to handle program which fulfills almost all wishes of the listeners. If you want to have more functions and settings, you can use the great program "SDR Radio", which is free of charge. There you have an almost unlimited number of functions and settings. This program is a piece of joy for the listener with a good knowledge of PCs. If that is too much after all, you can try the excellent program "HDSDR", which runs on the SDR-IQ, too.

How is reception with the small SDR IQ?

I compared it to the Perseus SDR and other hardware radios. Because reception depends very much on the software, the sound of the programs is different. I liked the sound of "SDR Radio" the best. You can adjust the sound with an equalizer. But it's not perfect. When setting the frequency, the spectrum  lags behind. HDSDR can handle that a lot better and makes the tuning of the frequency really smooth. I didn't like SpectraVue that much. Tuning the frequency  cannot be done without  some jerking. But all programs are almost noise-free and make good reception possible.  The large signal immunity of the SDR-IQ is rather good with IP3+15dBm. There were hardly any overdrive effects with my antennas: 35m long wire and Fenu-Loop/HDLA3. In this respect, the Perseus is a lot better. Sensitivity is not as good as for the other radios, but is good enough for DXing. All in all, a great receiver with the possibility of using other control programs. The right radio for the SDR beginner. Not too expensive and good value.

Control programs:
SDR Radio





S9-C Rabbit SDR

Bisher waren Italien, die USA, Russland und Deutschland als Entwickler und Hersteller für SDR’s bekannt. Jetzt gesellt sich ein fernöstliches Land dazu. China!

Aus dem Reich der Mitte kommt ein SDR Namens „S9-C Rabbit SDR“. Rabbit heisst auf Deutsch „Hase“. Dale Yu BA4TB, Funkamateur und Entwickler des S9-C, vertreibt ihn über seine kleine Firma Venus Information Technology Co. Der S9-C ist hierzulande absolut unbekannt, obwohl dieser schon seit Mitte 2015 erhältlich ist. Im Internet sind nur spärliche Informationen zum S9-C zu finden, weshalb der Bekanntheitsgrad sehr tief ist. Aus Neugier und mit wenig Hoffnung, fragte ich Dale Yu an, ob er mir ein Demogerät zur Verfügung stellen würde. Nach ein paar Tagen kam dann die positive Antwort. Dale Yu schickte mir daraufhin ein Demogerät. Das freute mich natürlich sehr, war ich doch wahrscheinlich der erste in Europa, der den S9-C Rabbit SDR testen durfte. So traf dann nach einer Woche der S9-C hier ein.

Das Gerät kommt schön verpackt in einem Buch-ähnlichen Karton. Als Zubehör ist ein USB-Kabel, je ein Pigtail von SMA auf die Norm PL und N, sowie ein Schaltnetzteil mit Länderspezifischen Adaptern beigelegt. Der S9-C ist ein hochwertig gebauter SDR. Das Gehäuse ist komplett aus gefrästem Aluminium und wird aktiv gekühlt. Das bedeutet, unter den Kühlrippen auf der Geräteoberseite, werkelt ein kleiner Lüfter der zum Glück nicht sehr laut ist.

Der S9-C wartet mit guten technischen Daten auf.

Die wichtigsten Eckdaten:
-- Architektur: DDC/DUC >Digital Down Converter / Digital Up Converter<
-- Frequenzbereich: 0.02-54MHz / 54-860MHz
-- 54MHz - 860MHz MAX2543 Tuner
-- Sampling Rate: 120Mhz
-- Sampling Auflösung: 16bit
-- AD-Chip: ADC LTC2208-16
-- Frequenzauflösung: 1Hz
-- Betriebsarten:  AM/FM/SSB/DSB/ISB/CW (Softwareabhängig)
-- +IP3 28dBm; +19dBm(Pre-Amp ein)
-- Pre-Amp 0-10dB
-- ATT -20dB
-- Eingebauter Preselektor
-- Antenneneingang mit Gas befülltem Überspannungsschutz
-- Betriebsspannung: 6V
-- Masse: 148.5 x 88.5 x 34.5mm (TxBxH)
--Antenneneingänge 2x SMA
--PC Anbindung: USB 2.0



Die Rückseite des S9-C bietet zwei SMA-Antenneneingänge. Eines für Lang, Mittel und Kurzwelle (HF), sowie ein Antenneneingang für VHF/UHF (U/V). Rechts davon befindet sich der USB2 und der DC-Anschluss für die 6V-Spannungsversorgung. Gut gelöst ist der kombinierbare Antenneneingang "HF+U/V". Mit der Steuersoftware(#SDR) kann man wählen, ob man nur eine Antenne für den ganzen Frequenzbereich nutzen will, oder ob man mit zwei Antennen arbeiten möchte. Dann verwendet man für VHF/UHF den Eingang "U/V". Bei 54MHz schalten die Antennen automatisch um, verwendet man zwei Antennen.

Öffnet man den S9-C, erkennt das kundige Auge sofort, dass an der Qualität nicht gespart wurde. Alle wichtigen Baugruppen sind zusätzlich geschirmt. Die Verarbeitung und das verwendete Material lässt kein Wunsch offen.



Steuersoftware für den S9-C

Bei einem SDR dieser Preisklasse, hatte ich eine eigenständige Steuersoftware erwartet. Dem war leider nicht so! Stattdessen setzt der Hersteller auf die bewährte Freeware "HDSDR" und "SDR#". Die nötigen ExtIO.dll's und USB-Treiber, muss man sich von der Webseite des Herstellers runterladen. Es stehen zwei Bandbreiten zur Verfügung: 1,2MHz und 3MHz. Die können beim Programmstart gewählt werden. CW-Skimmer und RTTY-Skimmer werden auch unterstützt. Diese habe ich aber nicht getestet.

Eine freudige Überraschung war, das  die ExtIO.dll für HDSDR, auch mit Studio1 funktionierte. Leider aber nicht vollständig. Die Regelung für den Vorverstärker fehlt.

Die Installation der Programme ging schnell von statten. Auch der USB-Treiber liess sich ohne Probleme installieren. Man musste nur noch die entsprechenden ExtIO.dll's in die richtigen Programmordner kopieren. Dann konnte es auch schon losgehen.


Der Empfang mit dem S9-C

Auf ein neues und unbekanntes Gerät ist man besonders gespannt. Ich begann also mit HDSDR. Nach ein paar grundlegenden Einstellungen und Anpassungen am Programm, konnte es endlich losgehen. Als Vergleichsempfänger nahm ich den bewährten Perseus SDR sowie den NetSDR+. Beide sind Topempfänger.

Auf der Webseite des S9-C steht, dass der Frequenzbereich ab 250Khz startet. Für europäische Verhältnisse nicht ideal. Das bedeutet, das die bei uns noch aktive Langwelle gar nicht enthalten wäre. Bevor mir Dale das Gerät schickte, habe ich das thematisiert und es fand sich eine Lösung. Dale optimierte daraufhin die Schaltung, damit das Testgerät die Langwelle und sogar darunter, empfängt.

So starten wir also bei der tiefsten Frequenz, die der S9-C empfangen kann. Der S9-C bringt den französischen Marinesender HWU auf 18.3KHz mit S4. Der Perseus bringt den gleichen Sender an der gleichen Antenne mit S9 +10dB. Allerdings bringt der Perseus mehr Störungen. Somit ist der Sender mit dem S9-C besser lesbar und auch besser sichtbar auf dem Spektrum. Am besten kommt HWU mit dem NetSDR+. S9+17dB mit bestem SNR. Das Zeitzeichen auf 60KHz brachte der S9-C mit S8. Der Perseus brachte es mit S9+10dB, der NetSDR+ mit S9+20dB. Das SNR war bei allen drei etwa gleich. BBC auf 198KHz, empfing  der S9-C mit S9+10dB. Die anderen beiden SDR's brachten etwa 10dB mehr Signal bei ähnlichem SNR.

Französischer Marinesender auf 18.3KHz

Zeitzeichen auf 60KHz

BBC auf 198KHz

Oberhalb der Langwelle waren die Unterschiede kaum noch zu hören. Die Unterschiede waren so gering, dass es sich nicht lohnte, von jedem Band ein Video zu machen.

Vergleich zwischen S9-C Rabbit SDR mit HDSDR und dem NetSDR+ mit SDR-Console V3 auf Mittelwelle.



Vergleich zwischen S9-C Rabbit SDR mit HDSDR und dem Perseus SDR. Empfang von Laser Hot Hits auf 4029KHz.



Vergleich zwischen S9-C Rabbit SDR mit HDSDR und dem Perseus SDR. Empfang auf 6585KHz in LSB.



Vergleich zwischen S9-C Rabbit SDR mit HDSDR und dem NetSDR+ mit SDR-Console V3. Empfang auf 11700KHz.



Vergleich zwischen S9-C Rabbit SDR mit HDSDR und dem Perseus SDR. Empfang auf 15580KHz.



Vergleich zwischen S9-C Rabbit SDR mit HDSDR und dem Perseus SDR. Empfang auf 17530KHz.



Der S9-C ist auch kompatibel mit der Studio1 Steuersoftware. Das einzige was nicht funktioniert, ist das aktivieren des Vorverstärkers beim S9-C. Hier zu sehen, das der S9-C auch ein guter UKW Empfänger ist. Der Frequenzbereich geht bis 860MHz.




Der S9-C Rabbit SDR ist ein Top- SDR der Mühelos mit den besten seiner Preisklasse mithalten kann. Die Verarbeitung der Hardware erfüllt hohe Qualitätsansprüche. Einschränkungen gab es lediglich beim Empfang auf den tiefsten Frequenzen unterhalb der Langwelle. Seine Kontrahenten, der Perseus und der NetSDR+ waren dort etwas besser bei schwachen Signalen. Der Empfang auf Mittelwelle und Kurzwelle waren praktisch identisch mit der Konkurrenz. Der S9-C empfängt bis 860Mhz. Hier lässt er den Perseus klar hinter sich.

Was leider nicht so gut war, waren die ExtIO.dll. Sozusagen die Verbindungssoftware zwischen dem S9-C und dem eigentlichen Steuerprogramm, war zum Testzeitpunkt nicht optimal programmiert. Die ExtIO.dll für HDSDR beherrschte nur 5KHz als kleinstes Abstimmschritt in der LO-Frequenz. Auch das Center-Tuning funktionierte nicht korrekt. Arbeitet man aber mit der "Tune" Frequenzabstimmung, funktionieren alle Abstimmschritte.

Für #SDR gibt es auch eine ExtIO.dll mit mehr Funktionen. Leider waren auch dort Fehler in der Programmierung vorhanden, die ein Betrieb mit #SDR zu sehr erschwerte. Deshalb habe ich #SDR nicht verwendet.

Eine Überraschung gab es dann mit Studio1. Diese tolle Software funktioniert mit der ExtIO.dll für HDSDR mit dem S9-C. Nur die den Vorverstärker des S9-C konnte nicht eingestellt werden, was kein Beinbruch war.

Bleibt zu hoffen, das der Hersteller die ExtIO.dll bald korrigiert.

gepostet, 17.10.2016




Ten-Tec RX-350

The Rx-350 is relatively rare in Europe. The radio comes from the USA and has not been in production since ca. 2004. The big black box is a so called SDR-receiver. That means that some functions are software-based, e.g.,  the band width filters. If you open the radio, you wonder how it all works. There is only a motherboard with some parts on it.  Well, let's close the box again and let's see what the radio is capable of. Reception is from 100 KHz - 30 MHz in the modes AM, AMS, LSB, USB, CW, RTTY and FM. It has 34 DSP band width filters, 1024 alphanumeric  memories,  a spectrum display up to 2.4. MHz ( not in real time, though), auto notch, BPT (band pass tuning) etc…. so it's well-equipped. It even has a 12 KHz IF-output and so you can decode DRM with your PC.  But there is no keyboard for entering the frequencies. Instead, there is a keyboard/VFO control unit available which can be attached at the rear panel.

In view of the scant interior of the radio, I was eager to test the receiver. I compared it to the Drake R8B and the Reuter RDR50B. This receiver is very similar to the RX-350 because it is completely digital. For an antenna I used a tried and tested 35m- long wire. I was surprised to find out that the RX-350 is a very low-noise radio on AM and has a pleasant audio.  Thinking of the JRC NRD545DSP, the RX-350 is a real treat for your ears.  But there is more to come! Seldom have I heard such a clean SSB signal from a shortwave receiver. It is practically noise-free.  Sensitivity on shortwave is very good as well. On the other hand, the RX-350 has shortcomings on long wave and medium wave. It is rather insensitive and AM synchronous is not very stable, it loses the synchronisation  relatively fast.  Large signal immunity was mostly good,  except a few overloads above 10 MHz.

A rather strange thing is the display of the band width filters. If you select 6 KHz in AM, you end up at ca. 12 KHz. In order to use 6 KHz, you have to select 3 KHz.  That is very unique! It seems as if the band width of a sideband is shown. This strange feature was kept in several firmware updates. In SSB, the display of the band width is normal.

The quality of the case is typically American: inexpensive! If you knock on the case, there is a clattering noise and it sounds hollow.

But apart from that, the Ten Tec RXC-350 is a good shortwave receiver with an impressive SSB audio. Many thanks to an anonymous hobbyist  for putting this radio at my disposal.

posted 03.09.2012



Winradio G31DDC Excalibur

What does "Excalibur" mean? It is about the sword, that the sorcerer Merlin rammed into a rock and anyone who could pull it out again had a right to the throne. According to the legend, it was Artus, who pulled the sword out and became king.

But in this context it is an entirely different story. It is about an excellent software defined radio, in short: an SDR. The Excalibur can only be operated with a PC or a powerful notebook. It is a so-called black box like the Perseus SDR and the SDR IQ.  The frequency range is from  0 - 50MHz. The whole frequency spectrum can be displayed in the lower part of the software. You can also select 30 MHz. The upper left display shows a selectable frequency range, called "DDC Band Width", which can be between 50 KHz and 2000KHz. To the right of it, there is the demodulator window.   It changes the width depending on the selected DDC band width.  In the demodulator window you can process the signal. All these windows can be displayed as waterfall or spectrum, except the demodulation window itself.  The Excalibur has all modes: AM, AMS (with selectable sidebands), LSB, USB, CW, FM, DRM, FSK UDM (user definable mode).  The Eibi-list, the HFCC frequency lists and user definable memories are also included. There is a variable notch filter and an audio high- and low pass filter. By the way, the Excalibur has three independent receivers (software) which are freely programmable. In short, almost every feature can be user-defined, which is good on the one hand, but on the other, there is much more to do which is not really easy for the casual  short waver listener. The Perseus SDR is more user-friendly because not so many features are user-definable. But if you are patient and take your time to become familiar with the Excalibur,  you won't be disappointed.

But now back to the receiving qualities. What does  Artus' sword sound like?  To start with: Top class!!

Compared to the Perseus SDR, the Excalibur proved to be more sensitive. Especially in the upper frequencies, e.g., Radio Ex. de Espania on 21610 KHz, the Excalibur is clearly superior to the Perseus.  The sound is excellent, too. Thanks to the audio high-/low pass filters and other selectable features, you can get the best possible audio quality.  But there are disadvantages as well: The large signal immunity is not as good as the Perseus'.  Below the long wave range, strong overloads from shortwave are noticeable.  Also, the noise blanker could be improved a lot. Because I live in the country,  near some pasture fences, "NB" would be very important to me. Unfortunately, the Excalibur cannot filter out the noise from the electric fences, whereas the Perseus can achieve that completely and the noise is eliminated. In conclusion, you may say that the Excalibur has great potential.  If the software is improved, the receiver will be top notch.  Analogue radios cannot compete with this flexibility.



Yaesu FRG-8800

During the 1990s, the FRG-8800 was the most favorite receiver of the shortwave listeners and was widely used.  It was a short wave receiver, which did not cost too much and offered good reception. Like many other receivers in this league, theFRG-8800 does not tolerate large antennas.  You should not use more than a 10m long wire. Active antennas should also be only used with caution.  The active antenna FRA-7700 could be attached without any problems, because it has a pre-selection feature.  The audio and the tone control work rather well. You can also add a VHF converter, which makes listening to 118 MHz - 174 MHz possible.  The FRG-8800 can also be used as portable radio because it has a battery case.  I am sure that the FRG 8800 is still in many a shack and serves its purpose. Way back then, it was a bestseller.




Yaesu FRG-100

The FRG-100 is a very good shortwave receiver, which is not built any more. That is really too bad because it has a very good large signal immunity, indeed, it is one of the very few hobby receivers which can handle long wires without much overdrive. The radio has 50 memories which store the modes and the filter widths.  Unfortunately, FM is only available as an option, which is not too bad, really. One thing which is missing, though, is a frequency input keyboard. Changing frequencies with Up/Down buttons is a little cumbersome.  But you get used to it.

How is reception?

By and large it is very good! The receiver can handle large antennas. Using a 20m long wire antenna and a vertical modified 5.5m long CB-antenna, there were no overload effects. Well done!! But just like other receivers,  the FRG-100 is not perfect, either. The AGC is too slow. In case of thunderstorms, the S-meter deflects because of the electrical impulses.  During the time the S-meter goes back to indicate the actual field strength, the receiver is mute. The same effect occurs when you scan the bands fast. There is a small and easy-to-build modification to make the AGC faster. The sound is not really impressive. It reminds you of the NRD 525/535. There is small modification for this problem as well. With these modifications installed, the FRG-100 will convince you.



Yaesu VR-5000

To start with, the operation of the Yaesu VR-500 is complicated. The frequency range is from 100Khz - 2600MHz, so the radio is not only for shortwave reception. It is solidly built, nice-looking an sounds good. The radio has many functions, I don't know how many. I didn't have the receiver for long. It should be mentioned that although being a scanner, the VR-5000 works rather well on shortwave, provided you use a preselector or an antenna which mustn't be too long. Otherwise, there will be overload effects right away.





Portable World Band Receivers

Degen DE1105

I imported this Degen DE1105 directly from China because it is not available in Europe. It is unbelievable what you get for a ridiculously small amount of60 $ or 75 CHF incl. shipping. This little radio is in a league of its own: 118x73x23 (HxLxW) and 1000 non-volatile memories divided into 10 pages. Modes are: FM (70-108 MHz), shortwave (5800KZ - 26100 KHz) and medium wave (522-1620KHz). It is even possible to listen to programs in stereo with selectable bass boost. It has one timer and three fully programmable alarm clocks. You can store the time, any frequency and the volume of the alarm clock. Reception with a 50cm long telescopic antenna is surprisingly good. Reception on shortwave is also very good because of the rather good selectivity of the radio. Listening to music on FM is a real joy especially with a good stereo earplug which is included. You will notice that there are no annoying noises when tuning the radio with the thumb wheel or the +/- button. Brilliant!! The DE1105 also has an integrated charger and a complete keyboard, a thermometer in °C etc, etc…. The workmanship is top quality. The front of the DE1105 is made of titanium colored brushed aluminum.

Scope of delivery: DE1105, protective bag made of flannel, 2 NiMh-batteries, carger and power supply stereo ear plug.

In sum, a totally fully-fledged world receiver which has no competitor in this price class.




Degen DE1106

The Degen DE1106! There had been rumors about this radio for a long time and now it is here. The dimensions are the same as  for the Eton E5 and the electronics are the same, too, except that the DE 1106 has some new features. The most important addition for the shortwave listener is without doubt the synchronous detector. Because the De1106 can also receive FM, a "RDS" function is included as well as air band reception. The radio has also a "Line in" jack to connect it to an iPod which makes it possible to us the Degen 1106 as an amplifier. All other features are the same as for the E5. The radio looks noble and well-manufactured but it does not a have a rubber surface as the E5.  The radio's interesting features are the synchronous detector and the "RDS" (Radio Data System) which works in the FM function. If the synchronous detector is switched on, the sidebands are freely selectable and so you can eliminate noise and disturbances from neighboring channels. This function works very well. Even when listening to weak stations,  the synchronous detector locks in place and remains locked in most cases. The "RDS" function shows the following information: station, title/artist, date, scroll text. But, of course, the station has to transmit this information.

Receiving range: 150 KHz - 30 MHz; 76 - 108 MHz; 118 - 137 MHz.

Modes: AM, synchronous AM with selectable side bands, USB, LSB, WFM (UKW)

Two selectable band widths

700 alpha-numeric non -volatile memories etc.

How is reception ?

The first thing to notice the almost non-audible noise on free frequencies.  You might think that the radio is defective or insensitive.  But this is not so! I have never seen or listened to a radio which has so little internal noise. I contacted the dealer and he assured me that the radio was  working fine. When I wrote this report, I  briefly compared the DE1106 with the Sangean ATS-909. Of course, the ATZS-909 is in a different league which should not be forgotten. Because the Degen radios have a good reputation, a comparison seemed natural.

Well, let's compare reception!

Basically, the DE1106 receives signals just as well as the ATS-909. The are differences in the upper frequency range, though.  From ca. 17 MHz and up, the ATS-909 is more sensitive.  Below 17 MHz, both receivers have the same sensitivity.  Reception on long wave  is not very good and the DE1106 is almost deaf. Also, medium wave reception is not really adequate . But the built-in ferrite antenna  has a good directional effect.

The band width filters of the DE1106 are more effective than the ones of the AT-909. In the narrow position, the sound is still pleasant and not muffled.

What is really good about the DE1106, is its synchronous detector. It locks into place in case of relatively weak stations and remains locked. Very well done!!  SSB works just as well as with the ATS-909.  Tuning  is easy and the intelligibility is good.  As is the case with these radios, large signal immunity is not very good and 900 KHz  above and below the selected frequency, there are image frequencies but admittedly , the transmitter has to be fairly strong to cause this effect.  Outdoor antennas can only be used with a preselector. The ATS-909 has a better large signal immunity.

FM works pretty well. The RDS sensitivity is the same as the one of the ATS-909. The airbands work fairly well near an airport. However, there is no scanning function for the airbands…

By and large a nice and interesting receiver with a synchronous detector that make makes up for the radio's small weaknesses.

The DE1106 is identical in construction to the Eton/Grundig G3

Soon, I will make comparison tests with several portable receivers.

This test can be found here.




Eton / Lextronix E1

Usually I only test radios, which I personally own. But because I do not always have access to every receiver,  I decided to review radios  which are on loan to me as well. Again a warm "Thank you" to an anonymous hobbyist.

Although the Eton E1 is not in production anymore, it is still in high demand because it is the best portable radio since the manufacture of the Sony ICF-SW77. Looking at the Eton 1 and holding it in your hands, the knowledgeable SWL might even think that it was produced in China. Wrong! It was made in India. The American company R.L. Drake had a role in the development of the E 1. Just like some other radios by Degen, the E 1 has a rubber surface.  Technically,  the receiver is quite good. For the first time, Pass Band Tuning (PBT) was put into a portable receiver. A well- functioning synchronous detector, which offers selectable sidebands including double sideband, is rare among portable radios.  There are lots of memories: 1700 memories, 500 of which are alphanumeric.  The others are linked to a special "Country Data Bank", i.e., you can allocate frequencies to specific countries.  That makes sense and thanks to a large display is easy to do. As a fully fledged world receiver,  the E1 sports FM, LW, MW and of course the entire shortwave range with the usual modes AM, AMS, LSB, USB. Interestingly, the E 1 does not have a ferrite antenna for LW and MW! All frequencies are received with a telescopic antenna; instead the E1 has an amplifier, which can be switched on, if necessary. Of course, the E1 has a jack for external antennas, which is non-standard, though. 


…is convincing! There were no overloads using the telescopic antenna. I compared the E 1 to the Sony ICF-2001D.  The audio comparisons can be found here.

Sensitivity is very good. The synchronous detector locks in on the signal, even if it is weak.  Thanks to the very narrow tuning steps of 10 Hz, reception of amateur radio and SSB is outstanding.  Tuning causes no noise, either. Super! Because of the three band width filters of 2.3 KHz, 4.0 KHz and 7.0 KHz you are well-equipped for every situation.  The filters are high quality, in thin plate encapsulated ceramic filters made by Murata. No effort was spared here.

The sound of the rather large loudspeakers is pleasant. With the bass- and treble control you can adjust the sound to your liking. The E 1 gives you a real treat! A portable radio with almost all technical subtleties. The large, clear and back-lit display makes easy operation possible. What's lacking is a RDS function for FM and PC-programmable memories. A negative point is the fact that the battery holders are badly or even not all padded. If you move the radio, the batteries are rattling in the battery tray. You can hear that very noticeably.

But still a great radio, which deserves much praise.




Eton E5

For some time now there have been reports and opinions about a Chinese radio factory called "Degen".  The Degen Company not only designs and builds radios for its own brand but also for others. One of these brands is Eton. The Eton E5 was supposed to come onto the market as Degen DE1106 but so far I have not been able to find one on the internet.  Only "Lextronic" and Eton sell the E 5. Because of the predominantly positive reviews of other E5 owners, I became curious and ordered an E5 at Nevada Radio in England. After only four days, the radio arrived. Included were the E5, a multi-lingual instruction booklet (German included), a protective pouch, stereo ear phones,  a cable antenna and a power supply, which unfortunately does not fit into Swiss outlets, so an adapter is necessary. The rechargeable batteries are not included, although it says so in the manual.   Finally then, I held the E5 in my hands.  First impressions: Very well manufactured, it lies snugly in your hands. The case has a sort of rubber surface which results into a good grip. I was a little surprised by the size of the radio: "so small"! From the ads and pictures on the internet it had appeared a little bigger, something like the Sony ICF-SW7600GR. The E5 has two options. Either from 76-108 MHz or from 87,5 - 108 MHz in FM. The range for long wave, medium wave and shortwave is from 150 - 30 000 KHz in AM and SSB. A new feature in this price class is the two selectable shortwave band widths. Some thing that is unusual for such a small radio: it has 700 memories divided into 100 pages each of which can be tagged with four letters.  This can be compared to the memory management of the Sony ICF-SW55, only that the E5 has five times as many memories.  The E5 has four timers, each of which can be programmed individually. It is very nice that the keyboard is standard. The keys have a very pleasant feel which results in comfortable operation. I especially liked the tuning with the VFO on the right side of the E5. When scanning the bands, there is no signal loss or noise between the 1 KHz steps.  You almost have an "analogue feeling".  The VFO also seems to have a flywheel effect. The faster you tune, the faster the frequency changes. Now, let's take a listen! Because I have had the E5 only for three days, this is merely a short comparison to the Panasonic RF-B65.  What you will notice immediately is the radio's good sound.  Stronger stations on shortwave or FM sound almost room-filling. I have never experienced that with such a small receiver.  In case the selected station is interfered by a neighboring channel, you have the band width selection at your disposal, which is very effective.  I was amazed at the reception of a Greek pirate station in the X-Band on 1645 KHz without any other help. The Panasonic RF-B65 had to give up and the station could be guessed at best.  SSB reception can be compared to the RF-B65. Weak signals could be tuned with the BFO and were understandable.  But where there is light, there is also shadow. Large signal immunity, which is very important for me, was not what I had been hoping for. Below the 49m band, you could clearly hear stations from this band.  In this respect, the RF-B65 excelled, there were no image frequencies, not a single one.  The SW 55 caused considerably more image frequencies.  I have to say that in this regard the E5 is better than the SW55.  Conclusion: A good companion on shortwave and FM at a unbeatable price. A serious competitor for the Sony ICF-SW7600GR!!.



Grundig G6 Aviator

Basically, the Grundig G6 Aviator is not a real Grundig.   The basic components carry the "Eton" label. The radio is probably built by Degen just like so many other radios made in China. And that was why I had the small receiver sent from the USA.  Although it carries the CE-label, it is not available in Europe and it is going to stay this way. The most interesting version is the so called "Buzz Aldrin Edition" which is the smallest radio with SSB and the air bands.  The radio covers the frequency range from 150 KHz - 30 MHz, the FM band in two varieties (76 MHz or 87.5 MHz - 108 MHz) and the air band from 117 MHz - 137 MHz.   The G6 has 700 alphanumeric memories just like the Eton (Grundig) E 5.  The G 6 has the same functions as the E5 except that the E5 has a selectable band width filter.  The G6 is the first receiver built in China of this size which can do without a clarifier for SSB reception.  SSB is tuned with a jog dial (main tuning wheel). In the "slow" position, there are approx. 10 Hz steps and an absolutely analog tuning feeling with no tuning noises.

How is reception?

I compared the "Aviator" to the Eton E 5.  By and large, reception was the same, which is remarkable for such a small radio. Also, sensitivity is about the same, with the G6 not quite as good in the long wave and medium wave range. The G6 has an extremely directional ferrite antenna so you can blank out interferences very efficiently. The bandwidth of the E 5 is much wider.  FM reception is on the same level as the E5. For stereo reception you have to use the headphones. Unfortunately, reception of the air bands is very bad. It's more like an extra to play around with. Sensitivity is not very high, either.  Also the scanning function does not work properly in this range, which is really too bad.

As is the case with almost all small world receivers, large signal immunity is not especially good. It is not advisable to connect an external antenna. This will result into overloads right away, at least in Europe. 

The radio has practically no tuning noises and only a very low internal hum. Great!!

Dimensions. : L x W x D: 124mm x 75 x 28mm.




Grundig Yacht Boy 80

I bought this Yacht Boy 80 at Media Markt. Reception in the European bands is rather good, but only in FM. SSB does not work satisfactorily because you cannot tune the frequencies adequately and the stations sound rather distorted. The Sony ICF-SW 7600 GR is much better in this respect; it even sports a fully fledged synchronous detector.  Tuning with the YB 80 works very well, though. With the VFO wheel, you can scan the bands without any noise.  If you want the signals to be stronger, simply connect the supplied wire with the antenna jack. But the YB 80 cannot handle the wire and flies off the handle!

Good audio quality, also on FM. SSB is useless.  If you do not demand too much of a radio, you may be happy with the YB 80, which costs 169 CHF.



Panasonic RF-B65

Every shortwave fan should be familiar with the RF-R65 because according to older tests it is the best portable world receiver. I could compare it to the Sony ICF-SW55. It can handle strong signals much better than the SW55. The SW55 produced some images from the 49m band between 5000 KHz and approx. 5500 KHz.  The B 65 shines in this respect….not a single image frequency.  This of course with its own telescopic antenna.  Regarding today’s reception conditions and in urban areas you should not ask for miracles from this portable receiver. You should leave the supplied wire antenna in its box because in most cases it will only produce overloads.  My motto is: "Less is more!". The B 65 does not shine with a lot of memories or other bells and whistles. The radio is simply good at what is expected of a good radio, i.e. good reception.  The RF-B65 is getting on in years, so, be careful when buying one!




Redsun RP300

The RP 300 was launched on the Chinese market at almost the same time as the Redsun RP2100.  What does the RP 300 offer? The first thing you'll notice is its tiny size. With W x H x D 120mm x 75mm x 25mm, the radio is really small. The antenna is a mere 45 cm long. But the radio does have the usual gimmicks, which modern Chinese receivers sport these days. It does not have DSP, though: The radio has 200 memories, an automatic scanning function without muting reception (!) and practically noiseless tuning. FM is from 70 MHz - 108 MHz (stereo with headphones), medium wave from 520 KHz - 1710 KHz, shortwave in two bands: SW 1>2300 KHz - 7500 KHz, SW 2>9200 KHz - 22000 KHz etc….


Prized at $30.00, you cannot expect miracles from this tiny radio. With some stations in the shortwave and medium wave range it was noticeable that the shielding of the electronics was not very effective. There were interfering noises, which were actually only present when you use the earphones. Large signal immunity is bad as could be expected.  Attempts to improve reception by extending the antenna failed because this resulted in overloads. But a direct comparison with the Aviator G6 by Grundig, which is about the same size,  showed that the Redsun RP300 is not really bad. It clearly beats the Grundig regarding sensitivity in the medium wave band.  Even the Tecsun PL-600 was not better on medium wave.  The RP300 is really good on medium wave. By and large, shortwave reception was on par with the Grundig G 6 Aviator. Selectivity is the same as the G 6.

FM reception of the RP 300 is adequate.  Sensitivity, noise, selectivity are not worse than the Aviator's.

Considering a sales prize of 33$ plus 10$ shipping, the Redsun RP 300 is an interesting receiver.  If you do not ask for the highest standards, you will be happy with the RP 300.  Good value for your money!



Redsun RP2100

I had this world receiver, the "Redsun RP2100", sent from China. Originally, this radio was built for the Chinese market, but now a version is also produced for the rest of the world and comes with English labeling, which, however, is not totally free of mistakes.  The receiver is offered in Europe under the name "Elta 3569". The RP 2100 is a world receiver, mainly for the listeners of broadcast stations.  It has FM from 87 MHz - 108 MHz, medium wave and shortwave 1'711 kHz - 30'000 kHz, divided into SW1, SW2 and SW3. There are ten memories for each of these segments, at total of 50 memories.  To be frank, I have never seen such a strange memory organization.  But the RP2100 has one special   feature, which at present is unique for a portable, cheap world receiver. It has got an IF-jack.  So you can connect the radio to a DRM, SSB-decoder, which is presently not available, however.  So far, this feature has not come with radios in this prize range.  It costs a mere 100.00 $ incl. shipping.  By the way, the RP2100 has also an alarm function, separate controls for bass and treble, 2 selectable band widths for medium wave and shortwave and RF-Gain. Everything else can be seen on the large display.  There is also a jack for an external antenna, but you need a TV-plug.  There is another unique feature: You can operate the RP2100 with two types of batteries.  The constructional quality is good and robust, it's better than the one of the Sony ICF-SW77, whose case makes a creaking noise.  The telescopic antenna is also of good quality, I will not comment on the antenna of the SW77. L

How is reception? Good to very good, indeed.  As far as sensitivity is concerned, it is not on the same level as the SW77, there is a little more noise.   Large signal immunity is nothing to write home about, either, in other words:  it is not especially good. I was under the impression that the upper frequency range was used as a sort of dump.  Starting at ca. 25 MHz and using the telescopic antenna, there were lots of image frequencies and signal mixes. Interestingly, this did almost not occur in the 41m and 49m bands.  But there are positive points as well:  The RP 2100 has super audio quality, whereas the audio of the SW77 is somewhat dull and muffled. The audio reminded me of the times when you listened to medium wave stations with a tube radio. That is how the RP2100 almost sounds.  A really full and great audio!  It is a lot fun to scan the medium wave frequencies   because there are almost no tuning noises. In comparison, the SW77 gets on your nerves in this respect. If you select a narrower bandwidth, noise is reduced, but the audio does not become dull.

FM works very well, also, even in stereo with headphones or line-out.  The RP2100 is a little more selective and sounds better.

If you just want to listen to the radio without having to spend a large amount of money, the RP2100 is a good choice.




Sangean ATS-909X

The Sangean ATS-909X is the direct successor to the well-known ATS-909W. Compared to this model, some features were changed, especially as far as reception of FM stations is concerned, which has been digitized. You will notice this because of the very good selectivity and the superb audio.  RDS, which was also possible with the old 909W, seems to react a little faster with the new 909X. And even the internal clock is synchronized with RDS.

Nothing much seems to have changed regarding shortwave reception, which is rather good; when using the telescopic antenna, large signal immunity is acceptable, there were no overloads to be noticed.  One flaw with the ATS909X is its weak sensitivity this can be remedied by having an antenna amplifier installed by an expert like Henry Mohr or Jürgen Martens.  The disadvantage here is a slight loss of large signal immunity.  Reception on longwave and mediumwave is satisfactory. The Sony ICF-7600GR is clearly better on LW and MW.  SSB reception on the amateur radio bands works quite well.  The 40Hz increments on SSB have not changed, either.

Further improvements are: Tuning on LW, MW and SW is uninterrupted by noise. It is now a lot more pleasant to be able to scan the bands without these noise effects.  You will notice the new design of the 909X right away.  I think it's well-made. And the nice display, which can be illuminated, looks very good, too.  The 909X has 406 alphanumeric memories, the 909W had 306.  Switching the bandwidth in AM is not very effective which the case with the old 9089W was also.

Sangean failed to implement a small, but important detail with the 909X: Sangean economized on the tuning wheel, which has click positions.  This wheel has some tolerance, which is due to the cheap mechanics of the tuning wheel.  Because of this tolerance, a selected frequency is not kept exactly at some positions. If you turn the tuning knob within a certain position, the frequency changes by several steps. That is simply unacceptable. My receiver showed this flaw in three click positions.

If you buy the 909X hoping to get better reception on LW, MW and SW, you will probably be disappointed.  The radio is not better or worse than the 909W, except for FM reception.  Because of the digital reception, the 909X is clearly at an advantage.  The audio is generally better than the 909W's.

The 909X is a very nice radio which offers the same reception quality as the preceding model.

(Written March 9, 2012)



Sony ICF-SW55

The Sony ICF-SW55 is a very well-known and good world receiver with a lot of special features: 125 alphanumeric memories, timer, world clock, SSB etc. etc. Reception on SW is very good and SSB works very well, too.  But all too often there are image frequencies.  This seems to be a common flaw with the small receivers by Sony.  Often, there are stations to be heard around 910 kHz of the selected frequency and with some signal strength at that.  Except for this, the SW55 is a top receiver, which offers a lot of functions like no other radio.

A hint:  In central Europe with strong stations around, you should operate the SW 55 only with its telescopic antenna, which will result in clean reception. (Less is more!)



Sony ICF-2001D

Without really looking for it, I came across the Sony ICF-2001D.  After finding out, which the seller was, I simply had to buy it because I knew him as someone who really takes care of his equipment.  I do not really have to write much about the ICF-2001D because it is known as simply the best portable world receiver which has been built so far.  Because the ICF-2001 is getting on in years (it was manufactured in the 1980s), a test of the radio is highly advisable before buying it.  Over the years, the electrical parameters change which leads to bad reception or even to defects.  But luckily, my ICF-2001D works very well. It once was serviced at Jürgen Martens' shop and he installed a high quality narrow 2.4 kHz bandwidth filter, a Murata CFJ455K5.

The ICF-2001D can really fill its owner with enthusiasm: Very good reception on all bands without any large signal problems.  The synchronous detector with its selectable side bands is a highly effective tool for unsteady frequencies. SSB works very well, too.  Receiving marine radio without the air bands on shortwave is no problem at all.  I connected the ICF-2001D to my Wellbrook ALA1530+ antenna and compared the results with my table top receivers.  Whatever I could hear with these receivers, I could also listen to with the ICF-2001D. To my astonishment, the ICF-2001D produced very few overloads.  You can use really highly effective antennas with this receiver.  But don't overdo it! It is a portable radio after all and is mainly designed for its telescopic antenna and not for too highly effective external antennas.  The ICF-Sw77 is absolutely suitable for DXing, but everybody knows that already.  Experiments with external antennas are really worthwhile.

In conclusion, it can be said the Sony ICF-2001D is still a superb receiver.  Not without reason, the synchronous detector is very popular.  The ICF-2001D is easy to operate and is solidly built.  When you see this radio in a nice and operational state, you should get it.



Sony ICF-SW77

The Sony ICF-SW77 was the last large world receiver built by Sony, which is really too bad. As the direct successor of the Sony ICF-2001D, the SW77 had to face many comparative tests. Sometimes, the SW77 was better, sometimes the 2001D. The SW77's range is from 150kHz to 30'000 kHz in AM, AM synchronous and SSB. There is also FM from 87,5 MHz to 108 MHz, in stereo when using headphones. When tuning shortwave frequencies manually, step widths from 1kHz to 50Hz are available. The radio has 162 alphanumeric memories. On the side, there is a jack for external antennas and a line-out.  Of course, there is a timer, alarm clock, and other features.  The constructional quality is acceptable. In this respect, its small brother, the SW55, is better. The case is not really stable.  There is a noticeable creaky noise. The telescopic antenna is not very stable, either.  If it is collapsed, it is easy to bend it. The SW 77 has so many buttons and controls, that it is almost impossible to operate the radio without consulting the manual, i.e., very complicated.  Now, what about the main thing? How is reception?  All in all, it is very good.  I compared the SW77 to the Redsun RP2100, which has about the same size.  Pricewise, they are worlds apart.  The SW 77 costs eight times as much as the RP2100.  The SW77 is a little more sensitive than the RP2100. There is less noise. What you will notice right away, is the tinny sound of the SW77 compared to the RP2100. The tone controls are not really effective.  In this respect, the RP2100 with its fuller audio is far better. The SW77 has two selectable bandwidths, just like the RP2100. Unfortunately, the filters of the SW77 are not designed ideally. They are selective, but the sound is muffled.  Here, the RP2100 is better, too.  On densely used bands, the wide filter of the RP2100 lets pass through whistling sounds caused by interferences, but the smaller filter is really superb. If activated, the interferences disappear, but the audio does not change.   The SW77’s narrow filter is very muffled and almost not usable for AM-reception. On the other hand, the large signal immunity of the SW77 is very good when using the telescopic antenna.  Across the whole shortwave band, I could not detect any large signal effects, which occurred with the RP2100, also during daytime reception. For a manual scan of the bands, the SW77 is not really suited. Why? Simply because of its annoying tuning noises. Further down, you will find an audio/video sample.  The receiver is suitable for DXing, but the noise and the interruptions when tuning the radio make scanning a real test of nerves. I cannot understand why Sony did not take care of this problem with this otherwise good radio.  When the SW77 became available, noise-free tuning was technically feasible. The "cheap" receiver Redsun RP2100 offers a far more pleasant tuning without almost any noise.

But in conclusion, the SW 77 is a very good world band receiver with many features, and not least because of its synchronous detector, it is a super receiver.




Sony CRF-1

This is one of the best shortwave receivers ever built by Sony, but it was not widely in use, which is probably due to its price.  When it reached the markets, it was about 3000 CHF.  This elaborately built receiver was mainly sold in Switzerland and the Netherlands.  In Germany, it was not officially approved by the authorities.  The case is completely made of aluminum pressure die-casting and guarantees high stability and shielding.  Only the upper lid and the front are made of plastic.  Although the CRF-1 was designed as portable receiver, probably only a few people used it as such, because it weighs 6.5 Kg!.  The radio receives 10 kHz - 30 MHz continuously in AM, USB, LSB and CW. Unfortunately, operation is complex and difficult. The whole frequency range is divided in 100 kHz segments.  When you have reached the end of the segment of a frequency range,  you have to go back,  pull out the tuning knob and have to select the next 100 kHz segment. Then you can continue fine tuning.  Compared with the tuning of the current radio generation, this is very tiresome. The Drake R7 has a similar tuning method.  But that is not all! If you want to tune the receiver exactly to the desired frequency, you also have to tune the preselector.  But luckily, this can be bypassed.

For a couple of days, I compared the CRF-1 with my other radios, which of course are more modern.  When tuned correctly, the CRF-1 was on par with the other radios. It is obvious that you cannot think in clear-cut terms when making these comparisons.   The CRF-1 has very wide AM filters and thus produces whistling noises caused by interference on busy bands. Also the narrow 4.4 kHz AM filter could not always guarantee sharp selectivity. For SSB, the results were better because of a 2.0 kHz band width. Sensitivity was as good as for the other receivers. Despite correct tuning, the CRF-1 produced overloads in the evening hours when connected to a 35m long wire antenna. But these flaws can be overlooked.  If you want to go "station hunting" you need the necessary time and some patience, anyway. Otherwise, you will not enjoy your CRF-1.

It is a wonderful radio, but not quite on par with modern receivers,; especially when DXing, you have to make compromises.

Please notice:  if you buy such a radio, the seller should guarantee you perfect functioning. Seldom, these receiver s have defective electrolytic condensators or need alignment, all which can result in a big repair bill.

Best thanks to Franz for making the CRF-1 available.

posted 02.12.2013




Sony ICF-SW07

The Sony ICF-SW07 is a small world receiver deluxe which has everything. As a successor to the SW100E it also has a synchronous detector built in. As small and exquisite the radio is, it is good as well. Reception is superb, especially with the supplied active loop antenna.  If you are inside and reception is becoming weak, you simply get out the loop and reception is back! The SW07 has a lot of alphanumeric memories, so you have a good overview of your stations. Compared to the YB80, the SW07 is at least a notch above the Yacht Boy by Grundig, except for the audio. Of course, the radio has 100Hz tuning in SSB.

A portable receiver of the luxury category, highly recommendable; but it comes at a price!


Sony ICF-SW7600GR

The only thing you can write about this radio, which is probably known by all shortwave fans,  is that it is a very good portable receiver which is on par with the SW07 as far as reception is concerned.  The most important differences are: SSB tuning with BFO (Clarifier), because there are only 1kHz steps available. There are no alphanumeric memories. Tuning is a little slow and because of its size, the audio is better than the SW07's. Not too many image frequencies. Convincing price/performance ratio!



Sony ICF-SW100S

As far as I know, the Sony ICF-SW100S is the smallest world receiver whose receive characteristics can be taken seriously. It offers the frequency ranges from 150 kHz - 30 MHz continuously in AM, AMS, USB and LSB. Additionally, there is FM from 76 MHz - 108 MHz the ICF-SW100 has 50 memories, which can be labeled with six characters each. Other functions, e.g., alarm clock, timer etc. are also built in.  Operation is straight forward and so you do not have to have the manual with you at all times.  It is really astonishing, what the Sony developers have all put in such a small case! It is a small receiver, which does not have to shy away from bigger radios as far as reception is concerned.  The strongest feature of the SW100 is the reception of shortwave stations in AM synchronous. This feature is really superb.  Who has not experienced the following situation: The selected station is interfered with by whistling noises because the neighboring station is so strong, that it affects the selected frequency.  When this happens, you activate the synchronous detector, select the sideband, which less interfered with and the annoying whistling is gone! Because the SW100 has also SSB, it is possible to listen to ham radio operators and aeronautical radio on shortwave.  On the other hand, the SW100 with its built in antenna is a little deaf, which is not necessarily a disadvantage. Thus the SW 100 does not suffer from overloads so easily as other world receivers.  If you want to listen to shortwave extensively, you connect the radio to a small wire coil or to the selective active antenna AN-100.  That is what I did. With this antenna, which is powered by the SW100, the radio gets attentive ears and you can do even DXing.  By pre-selecting three reception ranges, there is a preselection of frequency segments, which is good for suppressing large and strong signals, image frequencies etc.  All in all, a great receiver for your pocket, which is really fun and surprises you a lot. 




Tecsun PL-350

Since early 2005, the PL-350 has been available. But it was not sold in Europe and could only be bought in China, of course with Chinese labeling.  But for some time now, the PL-350 has also been available with English labeling.  I had the PL-350 flown in from Hongkong.  What sort of world receiver is the Tecsun PL-350? It is really small: 15x9x3cm (WxHxD) It has 550 non-volatile memories, which can be divided into three parts.  Frequency range:  MW: 522-1620 or 520 - 1710 kHz (9kHz or 10kHz  or 1kHz steps) and 1710 kHz - 30 MHz (1 kHz or 5 kHz steps), only in AM. FM from 76 - 108 MHz, with earphones also stereo. A n antenna attenuator with three positions, pitch control, alarm clock, timer etc. There are some unique features as well:  an antenna trimmer, which makes it possible to tune the frequency exactly. Because the PL-350 is only a single conversion receiver, naturally there are more image frequencies than in a double conversion radio.  But to overcome this problem, the PL-350 has something special built in: it has two switchable intermediate frequencies (455 kHz and 450kHz). If there are interferences on the selected frequency, you simply press the IF button in the lower right corner of the radio, and you will move the interfering frequency by +/- 10 kHz to the side and the desired frequency is clear.  That is really a great feature, which I had not seen before on any other world receiver. The radio also has a so called lighting timer, which means that between 7 p.m and 7 a.m the buttons or the VFO will automatically light up. Of course, you can select this feature for any other time.  Additionally, there is connector for an external antenna and a charger for NI-MH accus.  The scope of delivery is complete: accus, power supply (a travelling adapter is required), wire antenna, stereo earphones and a protective bag.  The constructional quality is very good.  How then is reception?  I compared the PL-350 with the Eton E5. What you can get with the E5, you can also receive with the PL-350. On MW, the E5 is definitively superior.  It simply receives the stations better and more intelligibly.  On shortwave, the differences are not so big. The PL-350 sound a little tinny, which, of course, has to do with the size of the radio. It also hisses a little more than the E5.  But the PL-350 has the IF-shift function, which the E5 does not sport and which is a huge advantage.  As already mentioned, there are image frequencies between 6200 kHz  - 6700 kHz, which also occur in table top receivers.  If, e.g., you are listening to Mystery Radio on 6220 kHz, stations coming from the 41m band on 6220 kHz may be audible.  With the E5 there is no chance of avoiding interferences, but the PL-350 has got a trick up its sleeve! You press the IF-Shift button, and voila! you move the image frequency to the side by +/- 10 kHz and the channel becomes clear.  Tuning the PL-350 is the same as the E5's, there is almost an analogous feeling to it. If you like tuning with some noise (short interruptions when tuning), you can re-program. Great! In my opinion, the filter widths were selected well. Sometimes, there are whistling sounds caused by interferences on busy bands.  FM is also convincing: good selectivity, good and loud audio.  All in all, a fun radio especially for the price of ca. 90CHF or 60Euro incl. shipping.




Tecsun PL-600

In Europe, the PL-600 is only available at some dealers. You can have it sent by EBay from Chinese dealers; that is what I did. For ca. 70 US Dollars, you get a receiver which fulfills almost every desire of a radio listener.  The only thing that is missing is a synchronous detector for AM reception.  Everything else is fine.

Most prominent features:
Frequency range: 100kHz - 30MHz; 76-108MHz (stereo with earphones)
Modes: AM, SSB tuning via a clarifier (BFO), WFM for FM
Double conversion
1 kHz and 5kHz tuning steps for shortwave;  1kHz, 9kHz and 10kHz for medium wave
Three-step attenuator
2 selectable bandwidths: 6kHz and 3kHz
Connector for external antenna
600 non-volatile memories
Noise-free tuning
Good audio
Solidly built
Shipped with protective bag, accus, charger, earphones, cable-antenna

How is reception?

Just like all portable radios, the PL-600 suffers from the" strong signal virus".  In Europe,  you have to be careful  when operating the radio with an external antenna. Not every received signal is a" real" one!

Fortunately though, the PL-600 has more good than bad sides!

I compared this receiver to the Degen1106. By and large, both radios have the same sensitivity and almost the same selectivity. Early in the morning, I could receive Radio Rebelde on 5025 kHz with both radios with the same signal strength. As far as signal processing is concerned, the Degen DE1106 was more flexible and with its synchronous detector, this receiver could suppress a RTTY-signal in the lower sideband.  With the PL-600 you could understand the program, but the RTTY-signal could be heard well at the same time and interfered with the other signal. It was no use switching to SSB to receive the station in "ECSS", because the PL-600 is not suitable for this trick, the audio is not clean. What I really liked, is the noise-free tuning with the VFO button, which also has a smooth feel to it.   DXing with the PL-600 is limited and only possible, when there are no interfering stations nearby.  Around 4 a.m., I could even receive Radio Clube do Para from Brazil and with the telescopic antenna at that. But nonetheless, the PL-600 reached its limit, because the AM- signals in SSB were audible rather poorly. The DE1106 worked very well, on the other hand!

FM works very well: high selectivity and very good audio with the loudspeaker and even better with the headphones. For its prize, you really get a very good world receiver, which is also convincing in its constructional quality.






Tecsun PL-880

When it reached the markets, the PL-880 made a splash. A pocket receiver with several selectable DSP-bandwidths, DSP-demodulation, synchronous detector and some other interesting and hidden features.  All this resulted in a lot of interesting debates and food for thought in the internet forums.  Mainly,  people puzzled over the hidden and undocumented functions.  Because I cannot buy every receiver, I depend on friendly people, who put the PL-880 at my disposal. After some searching, I found someone.  Harald Denzel loaned me his PL-880 and a big thank you to him!

The PL-880 had predecessor models, which were very much talked about, e.g., PL-600, PL-660 and now the new PL-880. The preceding models were all analogue radios and were real assets to the market.  In the PL-880, digital signal processing is used. Demodulation and filter band widths are achieved with DSP.

Die wichtigsten Eckdaten:

Basic parameters:
-- Frequency coverage: 100kHz-30MHz and 64MHZ-108MHz, configurable
-- Modes of operation: AM, AM synchronous, LSB, USB and WFM for FM
-- Band widths for AM: 2.3kHz, 3.5kHz, 5.0kHz, 9kHz
-- Band widths for SSB: 0.5kHz, 1.2kHz, 2.3kHz, 3.0kHz, 4.0kHz
-- Band width for FM: ca. 200kHz
-- Tuning steps long-, medium-, shortwave: 10Hz, 50Hz, 5kHz, 9kHz, 10kHz (depends on the mode)
-- Tuning steps FM: 10kHz, 100kHz
-- Synchronous detector with selectable sidebands, but no DSB
-- Attenuator in three selectable steps: (Local - Normal - DX)
-- Memories: 3050, divided in 25 memory banks
-- 3.7V Li-ion Accu
-- USB connector
Scope of delivery:
-- PL-800
-- Protective bag (brown imitation leather)
-- 3.7V Li-ion Accumulator
-- USB charging cable

For the power supply of the PL-800, Tecsun came upon an unconventional solution.  The radio has only a mini USB connector which also charges the 3.7V Li-ion accumulator. Unfortunately, the accu does not have standard size and so you cannot use standard size batteries.  This is very disadvantageous when your accumulators run out of power and you have no opportunity of recharging them.   If you want to use the radio with an external power supply, you have a serious problem!  You can only connect the receiver to a PC or to 5V switching power supply.  And you can imagine the consequences!  Receiving long- medium- and shortwave does not get along very well with switching power supplies and computers because reception is heavily interfered with. If you want to listen to long-, medium-, and shortwave seriously, you can only operate the PL-880 with accumulators.

A signal strength indicator that shows the values in dBµ and dB is very unusual for radios in this price range. These values do not mean a thing to the normal radio listener.  Only with the help of tables and some special knowledge,  these values can be converted  into the usual S-meter values.  dBµ and dB is mainly used for professional receivers.

Here a small conversion table from dBµ* to S-values (dBµ is dBµV = voltage)*

dBμ              >>

-14 -8 -2 4 10 16 22 28 34 44 54 64 74 84 94

S-Wert        >>

1 2 3 4 5 6 7 8 9 9+10dB 9+20dB 9+30dB 9+40dB 9+50dB 9+60dB

The dB- value stands for the S/N, which equals the SNR = signal/noise ratio. The higher the value, the better the intelligibility. In theory, anyway.

The constructional quality of the PL-800 is high. The controls are placed conveniently and allow for easy operation of the receiver. A novelty for a pocket receiver are the two tuning knobs.  One is for coarse tuning, the other, the smaller one,  is for fine tuning to at least 10Hz. Thus you can stop conveniently at the desired station without changing the tuning steps and then do the fine tuning.  A good solution!  Tuning on long-, medium-, and shortwave is without signal drop-outs  and provides an absolutely analogous feeling.  The PL-800 has an antenna connector for shortwave, but unfortunately, not for long- and medium wave. There is also a line- out and a stereo headphones connector.  As a fully-fledged world receiver, the PL-800 can also receive FM  in stereo with headphones.  When tuning the FM-band, you will notice signal drop-outs, which are kept to a limit, though.  Additionally, there are other functions like alarm clock, automatic memory function etc., which I will not discuss.

How does it play?

I tested the PL-880 for some weeks and examined it thoroughly. As reference I used the Sony ICF-SW7600GR.  The PL800's reception is rather noise-free and has a very good, almost bass-like audio. Crackling noises and hissing were less noticeable with the PL-800 than with the ICF-SW7600GR. I really was surprised at the good reception of long- and medium wave. So far, most radios made in China had been rather deaf in this range, but this cannot be said about the PL-880. Here, the Tecsun clearly beat the Sony. Sensitivity, noise and last but not least the DSP-selectivity helped the PL-880 to a very good reception.  But there is a downside, nonetheless.  The legendary synchronous detector of the PL-880 could not convince me.  Neither in the case of weak nor strong stations, could the synchronous detector improve reception.  The detector "bubbled" and lost synchronization rather quickly.  It was just useless. Maybe the detector will be improved with new firmware at a later date.  Anyway, the synchronous detector of the Sony was much better.

The good reception quality of the PL-880 could also be noticed on shortwave. The noise-free and pleasant reception was convincing and receiving stations with the built-in telescopic antenna was never subject to criticism. And there were no overloads, either. The Sony, on the other hand, showed some flaws in this respect.  Sometimes you could hear "ghost stations" below busy broadcast bands.

At the time of testing, I had the indoor antennas Reuter RLA3A and the Grahn GS5-SE/ML3 at hand and I took the opportunity to operate the Tecsun with these antennas.  The PL-880 worked very well with the Grahn antenna. Reception was improved considerably and there were no overloads.  It didn't go to well with the Reuter antenna, though.  The receiving level was better, but at the expense of the signal/noise ratio and there were overloads at times.

SSB-reception was good, but the Sony sounded clearly better. The audio of the Pl-880 has a scratchy sound which is due to a suboptimal AGC. And the audio was muffled, too.  But tuning with the two knobs was superb! When turning the small knob slowly, tuning was in 10Hz steps. When turning faster, the flywheel effect is activated and the steps are 50Hz.

There is no criticism as far as FM reception is concerned. Pleasant audio, excellent selectivity and good strong signal performance convinced me right away. Too bad though that there is only one band width.  With such a high-tech radio, RDS would have been good, too. The Sony was the loser in the FM reception category.  There were some overloads and it did not reach the audio quality of the Tecsun.


Hidden functions

Unfortunately, it was impossible to find out, why Tecsun is hiding the following functions or did not activate them.  Some functions are certainly useful; others do not seem to be fully developed. The hidden functions can be activated by pushing some of the buttons.  Presently, I know the following features:

With the radio switched on
(These functions were found on the internet)
Warning: When using the following functions, you do so at your own risk! Your radio may be damaged!
Synchronous detector:
--press the USB or LSB button for three seconds
Noise reduction while tuning:
--Press button "9" for three seconds and select the value with the rotary knob. Press button "9" again to save the setting.
Noise reduction during reception:
--Press button "6"for three seconds for switching on/off
Changing De-Emphasis for FM
--Press button "5" for three seconds and select either 50 or 75. 50µs is for Europe, 75µs for USA. This only works in the FM mode.
Frequency calibration for long- and shortwave
--Select a strong station and switch to USB or LSB. Then fine-tune with the small tuning knob until reaching Zero Beat.  Press the "Snooze" button for three seconds and wait for the correction in the display. Press "Snooze" again to save the value.
With the radio switched off
Display control, firmware number and date of manufacture
--For control of the display keep the button "AM BW" depressed. Release the button and press again for firmware number. Press once again for date of manufacture.
Line-out level
--Press button "7" for three seconds and select a value with the rotary knob. Press the button again to save the setting.
Activation of the display of seconds
--Press button "8"for three seconds and wait for the display to light up.
Shutdown threshold for weak batteries
--Press button "4"for three seconds and select the value with the rotary knob. My recommendation: 3.5V.
Operating time since last charging the accumulators
--Press button "VF/VM for three seconds
Sorting the memories
--Press button "M" for three seconds.


For its reasonable price and its DSP- technology, the Tecsun PL-880 is a superb pocket receiver.  It outshines almost all of its competing products. But SSB-reception and the synchronous detector were disappointing, the detector was unable to improve reception in any given situation, it even made it worse. In AM, the audio of the PL-880 is excellent and makes the synchronous detector superfluous.  FM reception is sophisticated.

The PL-880 still has some minor flaws, which can be remedied by later firmware updates. Whether this can be done via the USB connector, I do not know.

The hidden functions left me with some mixed impressions. Either you make them available without  many lengthy searches or you deactivate them…

A recommendable receiver!

posted at October 18, 2014




Empfänger Bausätze

Junior 1 von Stampfl

Heinz Stampfl (HB9KOC), who is well-known because of his hand-made precision Morse keys,  has also a heart for radio listeners. For some time now, Heinz has been tinkering with several receiver concepts, which he also shows on his web site. It is his aim to be able to offer these projects as assembly kits in the future.  But unfortunately, this is not as easy as it sounds. On the one hand, enough kits have to be produced for the project to be profitable, and on the other enough buyers have to be found as well. These days, when everything can be bought as "plug and play" such a projects bears a big financial risk.

Despite these risks, Heinz Stampfl now would like to offer a small kit: the Junior 1.

Description of the Junior 1 kit (by Heinz Stampfl)

The Junior1 one is a double conversion shortwave receiver, which can easily and quickly be assembled.  No alignments, no measuring equipment or special knowledge of high frequency technology are necessary. Junior 1 is meant to be a small project for the young and for the young-at-heart listeners, who are interested in radio technology.
The main part of the radio is an AM/FM-IC from the former DDR (East Germany), the A4100D, which was especially developed for battery-powered devices.  According to the data sheet, the A4100D has a particularly good signal/noise ratio for AM and FM and only requires little external wiring.
The tried and tested NE612 is used for the front end mixer and for the oscillator.  It is possible to connect a low-resistance dipole with a coil. Tests, which were run during the early evening hours, surprisingly showed no overloads when using a G5RV.  If you want to use the Junior 1 as a portable, 1.5m of Litz wire should be enough for the high-resistance antenna connector.
For cost-reasons, the 1. IF-filter comes as a ceramic resonator. Because of its high bandwidth, it does nothing for the near-selection of the radio and so no effort was spared for the 2. IF-filter. The conversion oscillator (10.245 MHz) is a monolithic and adjustment-free component. If you are fond of experiments, you can design you own favorite frequency range by altering the input circuit and the oscillator stage. A LED is used as a field strength indicator.  You can connect a µA-meter with a suitable series resistor.
In the original design, the input circuit and the oscillator are mainly for the 49m/41m band. A local oscillator makes SSB-reception in the 40m ham radio band possible. But let me make clear: Due to the high 1. IF-frequency and the varactor diode of the LO, SSB reception is a little adventuresome and nothing for experienced DXers.  But nonetheless, it is certainly exciting for someone who has never listened to ham radio operators.  
Power consumption and the supply voltage range is from 7.5V to 16V at approx. 70mA. A LM380 with a 4 Ohm loudspeaker makes for good reception.
In conclusion, the Junior 1 has a deliberately simple concept, but still is an effective receiver, which shows good audio, high selectivity, high sensitivity and at the same time good signal processing.
The case is made of blue anodized aluminum. The labeling is etched with laser. 



Heinz Stampfl was friendly enough and put a Junior 1 at my disposal for testing purposes.  The radio came assembled, though, because I did not have the time for putting it together.

As can be seen in the picture, the receiver has the serial number 001. It is the first radio which comes out in the open.

I had the Junior 1 on my table for over a month and used it at every opportunity.  I mainly used external antennas for the Junior 1. To make this possible, I added a BNC-connector. To test the potential of the kit, I wanted to avoid interferences in my house. On the front of the radio, you can plug in a piece of wire as an antenna with a banana plug. There is also a connector for grounding the radio. To avoid overloads, I used a switchable attenuator and because the Junior 1 is not made for highly effective antennas, I used a 10 - 20dB attenuation.  Interestingly, there were no overloads. There were hardly any "ghost stations" to be heard and only during the early evening hours and very weak at that. Because the radio is a simple do-it-yourself project, the Junior 1 needs a little warm-up time because the oscillator drifts a little. You can power the receiver with either a 9V battery or an external power supply with 7.5V to 16V.

Because the frequency is not shown, tuning is a little unusual. Starting with the rotary knob all the way to the left,  you have to turn it five times to reach the 40m ham radio band. Then you switch to SSB and scan slowly and carefully through the band with the big tuning knob until you hear a station.  After that fine tuning is done with the left -0+ knobs until you hear the station clearly. With a little practice and patience, it works rather well. The low noise and the bright and intelligible audio are surprising.  Selectivity is good enough to receive SSB signals in the 40m band.  If you tune further down, you will come to the 41m broadcast band.  Then you select AM again and can listen to programs.  Comparisons with other radios showed rather high sensitivity.  Very weak stations on a clear frequency could be listened to well and intelligibly. It is clear that the Junior 1 is no DX machine, but for such a small radio, reception is rather good.


Heinz Stampfl dared to start an interesting do-it-yourself project. For young beginners, who are interested in building a radio themselves, the Junior 1 is the ideal kit.  But also for experienced listeners, the kit is certainly interesting.  For assembling the radio, you need interest and some experience with a soldering iron. It remains to be hoped that the Junior 1 will become a success. Perhaps then a kit will appear on the market, which Heinz will proudly present on his web page. …

The Junior 1 kit is now available at "Stampfl Morsetasten" and costs CHF 72.-

Beginning in 2015, the Junior 1 will be available in the shop of the "Funkamateur" magazine.

The assembly instructions can be downloaded here.

posted November 22, 2014