SDR - Software Defined Radio
Portable World Band Receivers
Portable World Band Receivers
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!
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!
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.
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)
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!)
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.
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.
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.
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!
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!
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.
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.
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.
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.
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:
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)*
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.
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:
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
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)
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