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Afedri LAN-IQ

 

Alexander Trushkin (4Z5LV) has been developing and producing SDR receivers since 2012. These are offered under the "Afedri" brand on its website. Afedri means: Analog Front-End Digital Radio Interface and refers to the DDC chip Afedri8201 from Texas Instruments.
The majority of Alex's products are known under radio amateurs, but less under radio listeners. Now Alex has expanded his range of SDRs with the LAN-IQ, which has very interesting properties. The LAN-IQ is an extended version of the
Afedri SDR-NET, which is a pure black box receiver. This means that the SDR-NET can only be operated via the computer. The LAN-IQ, on the other hand, becomes a standalone receiver thanks to the expansion built into the same housing. This extension consists of a circuit board on which a touch display and all necessary control elements are contained. The aluminum housing from Hammond is kept simple and makes a valuable impression.

 

The most important key data of the LAN-IQ

-- Frequency range: 30KHz - 35MHz> Direct Sampling
-- Frequency range: 35MHz - 1700MHz> Tuner R820T2
-- Low pass filter: 0 - 36Mhz
-- High pass filter: 35 - 1700Mhz
-- MDS (smallest receivable signal above the background noise) at 500Hz bandwidth: -136dBm (30KHz - 35MHz)
-- MDS (smallest receivable signal above the background noise) at 500Hz bandwidth: -136dBm (50MHz - 435MHz)
-- ADC: 12bit - 80MSPS
-- Tuner chip R820T2 (VHF / UHF)
-- Frequency stability: 0.5ppm
--3.5 "touch LC display with 480x320 pixels
-- SMA antenna connections for HF & VHF (also available with BNC)
-- Mini USB connection
-- LAN connection
-- built-in network interface
-- Speaker / headphone jack: 3.5mm stereo jack
-- Operating voltage 5V via USB socket, via hollow socket 7-10V
-- Power consumption: 850mA
-- Dimensions: 120x78x27mm (WxDxH)
-- Aluminum casing
-- Weight: 280g

Scope of delivery:
-- LAN-IQ
-- stylus
-- Y USB cable

Standalone operation

-- Can be operated via touchscreen
-- Operating modes: AM, LSB, USB, CW, NFM, WFM (stereo)
-- Digital modes decoder: RTTY, PSK, BPSK - output in plain text
-- Tuning steps: 1Hz, 10Hz, 100Hz, 1KHz, 10KHz
--Audio bandwidths:
    AM: 5, 9, 20KHz
    SSB: 2.4, 2.7, 3.3KHz
    CW: 250, 500, 1000Hz
    NFM: 6, 9, 12.5, 22KHz
    WFM: 80, 150, 300KHz (depending on the sample rate)
-- Bandwidths of the spectrum: 96KHz, 192KHz, 384KHZ, 768KHz
-- DSP noise reduction
-- Automatic and manual notch filter
-- DC offset filter. Manual removal of the DC peak in the middle of the spectrum.
-- 100 station memories
-- Spectrum views adjustable.

PC operation

-- Operation via LAN or USB
-- Compatible control programs: SDR-Console V3, HDSDR, Linrad, Winrad, Studio 1, CuteSDR, SDrDx, Quisk, PowerSDR_mrx, SDRunoExtIO, SDR # limited to 35MHz
-- Operating modes: AM, AMS, LSB, USB, CW, NFM, WFM (stereo) etc. (depending on software)
-- Bandwidths of the spectrum: 96KHz, 192KHz, 384KHZ, 768KHz -> up to 2MHz (depending on software)

Block diagram of the LAN-IQ

The LAN-IQ works from 30KHz - 35Mhz as a direct sampler and from 35MHz - 1700MHz as a tuner-based SDR with the well-known R820T2 chip.

 

Peculiarities in standalone operation

In standalone mode, the LAN-IQ has a few special features that I will briefly discuss here. A Y-USB cable is supplied with the LAN-IQ. This is required if the device is operated on USB2. If the LAN-IQ is operated with large sample rates, it needs about 850mA. Because a USB2 connection only supplies 500mA, the LAN-IQ is then undersupplied and could not function properly. With this Y-cable you can use 2x USB2 sockets and then have 1000mA available. Of course, this also applies if the LAN-IQ is controlled via the PC. The best thing is to use a USB3 connection or an external low-interference 5V power supply. The device also has a hollow socket for power supply. This can be used to apply a voltage of 7-10V. Unfortunately, it turned out that the LAN-IQ gets very warm if you feed it through the hollow socket. This is due to the voltage converter, which regulates down to 5V. Basically I recommend to supply the LAN-IQ with voltage via the USB connection.

Ideally, the LAN-IQ is operated with the supplied stylus. The touchscreen can of course also be operated with your bare fingers. Then you make a typing mistake very quickly because the typing areas are small. You can quickly find out that if you swipe the lower spectrum over the display, the frequency can be adjusted with the previously selected tuning step. In the upper waterfall display, tap on the display to set the desired frequency. The tap does not set the frequency in the selected step size, but in 1 Hz steps.

Use the "Step + & Step-" buttons to set the step size. The step sizes are not as usual as with a wideband receiver. Each press of the step buttons increases or decreases the step size by a factor of 10. This makes it difficult to set a frequency precisely. Also because the set tuning step is not rounded. The exact setting of a frequency is possible with the direct input via the numeric keypad which can be activated by pressing the frequency display or "Mod." can call.

The AM operating mode was somewhat neglected. The bandwidth filters sometimes have unusual values ​​and the AGC cannot be set. There is no adjustable AGC in SSB either. You don't have the option to choose between AGC "Fast - Medium - Slow". AGC control is certainly present, but it is too fast. That is why the LAN-IQ rushes up quickly during the speak breaks. This is somewhat reminiscent of the JRC NRD-545 DSP, which also had no adjustable AGC in AM.

The other special feature of the LAN-IQ in standalone mode is the programming and operation of the 100 frequency memories. The LAN-IQ has memory banks in which only defined frequencies can be stored. The memory contents must be called up individually by entering the memory location number. It is not possible to scan the memory in the current firmware version, which makes working with the memory functions very difficult.

Memory 0-13 are reserved for amateur radio frequencies. Frequencies outside the amateur range are not saved.
Memory 14-89 are for all frequencies, no matter in which band.
Memory 90-98 are used to store the value of the 1st heterodyne frequency. Applies when the transverter mode is active.
Memory 99 is used to keep current transverter memory.

All other functions can be easily mastered by the experienced operator.

In the pictures below you can see that my LAN-IQ has a tuning knob to the left side of the display. This is not self-made, but can be ordered as an option. However, the manufacturer (Alex) advises against choosing this optionMemory! The problem with this option is that the encoder used is mechanical and does not have a long lifespan. It is also important to note that this option is excluded from the guarantee. My LAN-IQ also has a stand to put it in a comfortable working position. I installed this stand myself and is not included in the scope of delivery.

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LAN-IQ in standalone mode

With the built-in touch display, the LAN-IQ can also be operated without a computer. Due to the small display dimensions, working with the LAN-IQ is a bit fiddly. But if you use the supplied stylus as an aid, you will get along well with the device after a little getting used to it. While browsing the Internet, I came across an option that the manufacturer of the LAN-IQ does not offer directly. Some LAN-IQ devices, allegedly not all, are prepared for the installation of a tuning encoder. On the board on which the display is mounted, there is a place where you can install a mechanical encoder. Upon request, an encoder was installed in my LAN-IQ. Unfortunately, the joy didn't last long. The encoder used is not suitable because it have detents. The reason for this is that each detent gives two impulses. This means that the frequency changes by two steps per detent. Fortunately, I still had Bourns encoders of the same type from an old project. These had no detents. I immediately replaced the encoder. And lo and behold, it works perfectly!
Now it's time to test and compare. The LAN-IQ was tested and compared over several weeks under various conditions. The Malahit-DSP was available as a comparison device. I mainly used the Datong AD370 as an antenna. Overall, it is the quietest antenna here.
So we start at the lowest frequency at which a signal can be received. The Norwegian marine transmitter JXN send on 16.4KHz. In the operating mode CW with + 800Hz offset, the marine transmitter with its FSK transmission is clearly audible. The Malahit-DSP doesn't go that deep. Therefore, the LAN-IQ is the only one that can receive below 50Khz. The telegraph transmitter SAQ on 17.2KHz should be receivable in standalone mode without problems. For all other comparisons I made audio recordings so that everyone can form their own opinion.

Audio comparisons
 
The audio comparisons clearly show how the LAN-IQ behaves in standalone mode. The Malahit-DSP must also be mentioned that it is still under development in terms of software. Some recordings are from stations are just above the noise floor. I therefore recommend using headphones when listening to the audio comparisons.
 
Second 0 - 15: Afedri LAN-IQ
Second 15 - 30: Malahit-DSP
 
60khz CW
Timesignal
1602khz AM
Radio Milano
3703khz LSB
Amateurfunk
4700khz AM
Radio Mystery 21
5140khz AM
Radio Charleston
5505khz USB
Shannon Volmet
6205khz AM
Laser Hot Hits
8743khz USB
Bangkok Meteo
9455khz AM
Radio Free Asia
11575khz AM
Radio Ashna
13605khz AM
Radio Marti
15285khz AM
Radio Cairo
17570khz AM
Adv. World Radio
18138khz USB
Amateurfunk
28257khz CW
BAKE DK0TEN
101.5MHz FMW
Radio SRF1

 

The LAN-IQ can be seen in operation in the video. For standalone operation there is a headphone or an active speaker. In this case the active speaker Bose Soundlink Mini II. It gives the somewhat thinny sounding LAN-IQ a little more sonority. The LAN-IQ can also decode digital operating modes. That means RTTY, PSK and QPSK. Unfortunately, only baud and shift rates for amateur radio operation are available. Pity! In the video from minute 6:10 you can see how the LAN-IQ copes with it. Decoding works well once you have found a station.

 

 

LAN-IQ as a portable SDR

With its concept, the LAN-IQ still offers the possibility of portable use. With a good 5V power bank, the LAN-IQ can be operated outside of the shack for many hours. My power bank has 10400mAh and easily hold 10 hours. The MLA30 active loop is also connected to it.

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LAN-IQ in PC mode

The LAN-IQ can be connected with the PC in two ways. Either via USB2 or via the LAN connection. If you operate the LAN-IQ via USB2 you quickly determine that the spectrum bandwidth with max. 250KHz. Dependent from the sound card of the PC. The LAN connection belongs for significantly more bandwidth. This allows up to 2MHz bandwidth up on the monitor. If you choose LAN operation, you have two functions to connect to the network. You can connect the LAN-IQ directly to the network card of the PC, or you can connect it to a router. If you go through the router, you have the option of remotely controlling the LAN-IQ via the Internet, because it has a built-in network interface. My device is connect on the router, that simplified the configuration.

Choice between USB and LAN connection with the SDR-Console V3.
 
Bandwidth over USB max. 250KHz
Bandwidth over LAN max. 2 MHz

The LAN-IQ can be operated with many programs. Shown below in operation with the SDR-Console V3, HDSDR in connection with the Afedri Control Box and SDRSharp. SDRSharp offers only support up to 35MHz.

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Sensitivity test & audio comparisons

The LAN-IQ is a direct sample SDR with a 12bit ADC from 30KHz - 35MHz. According to the technical data, it should be quite sensitive. An MDS of -136dBm (smallest audible signal above the noise) makes you curious. These are values ​​that the Winradio G33DDC Excalibur Pro delivers. The following comparisons should show whether it is really as sensitive as the G33DDC. Antenna compatibility is also an issue. I use normal hobby antennas like the Datong AD370, the cross loop with the Reuter amplifier RLA4/2E and a few other antennas. Every good hobby SDR should tolerate these antennas without complaint. But now to the comparisons in PC mode!
The Swiss CW beacon HB9AW transmits in the 60m amateur radio band. In order to check the propagation conditions in this band, the beacon transmits in quick succession with five different transmission powers. The distance to the beacon is approx. 68km as the crow flies and is therefore very suitable to test the sensitivity of receivers and antennas. In telegraphy the call sign HB9AW is sent on 5291KHz in CW with 10 W. This is followed by five lines of two seconds each, which are reduced in performance. The first line is transmitted with a power of 10W, the second with 5W, the third with 1Watt, the fourth with 100mW and the fifth line with 10mW. In the comparison below, the LAN-IQ and the Winradio G33DDC were operated simultaneously on the Datong AD370 antenna. The audio was switched back and forth between the two receivers for comparison in order to compare the audibility of the weakening signal. 

 

Differences between the receivers can best be determined with audio comparisons. Of course, this always depends on the settings of the respective receivers. Accordingly, both receivers were set for the best possible reproduction. The noise canceling functions have not been activated. The bandwidth filters and the modulation type were always set the same. The appropriate station was carefully selected so that it could be received as consistently as possible over the recording period so that the differences can also be assessed. It sometimes took several tries. Some recordings are from stations just above the noise floor. I therefore recommend using headphones when listening to the audio comparisons.

 

11.9khz-CW
Alpha Signale
198khz-AMS
BBC4 
1710khz-AMS Serbischer Radiopirat
3685.5khz-LSB
Amateurfunk
6005khz-AMS
Radio Belarus
8743khz-USB
Bangkok Meteo
9420khz-AMS
Voice of Greece
10051khz-USB
Gander Volmet
11253khz-USB
RAF Volmet
11780khz-AMS
R. Nacional Amazonia
13238.2khz-CW
Channel Marker
13720khz-AMS
R.Saudi
14205khz-USB
Amateurfunk
15690khz-AMS
RadioFarda
17750khz-AMS
China Radio Int.
28257khz-CW
Bake DK0TEN

 

Conclusion

Standalone operation

The sound differences from the Malahit DSP are clearly audible. The LAN-IQ rushes significantly more than its opponent. On the whole, this is not tragic, but in the long run it is uncomfortable to work with headphones. This is due to the lack of adjustability of the AGC. The sound in standalone mode is a bit thin, but understandable. The antenna compatibility gave no cause for criticism. I was unable to determine any intermodulations during the entire test period. Overdrive effects only occurred when the RF gain was turned up fully. Unfortunately, a few things have not been consistently implemented by the manufacturer. As a standalone SDR, the LAN-IQ is very tailored to the radio amateur. You notice this in the operation, in the underexposed operating mode AM and in the digital operating modes. I only briefly tested the reception above 35MHz. It receives well on FM, even in stereo but without RDS. Unfortunately there is no tuning step for FM radio! The largest tuning step is 10KHz. There was almost nothing going on in the aeronautical sector due to the Corona crisis. Nevertheless, the tower from Zurich Airport was sometimes heard at 118.100MHz.
The tuning button greatly simplifies frequency tuning! Even if the manufacturer gives no guarantee, I can still highly recommend it. Tip: Do not install encoders with detents!

PC operation

The LAN-IQ shines in PC mode! Its rival, the Winradio G33DDC, has been one of the best SDRs ever since it was released. The LAN-IQ with its 12bit can largely keep up. The sensitivity in particular is on par with that of Winradio. The only differences were in the sound reproduction. Although the LAN-IQ should receive from 30KHz, the Russian alpha signals can be received at 11.9KHz.
The LAN-IQ currently offers a unique concept. A black box receiver with the option of using it as a standalone device. It is small, light and offers very good performance for a 12bit SDR. The possibility to operate via USB or LAN make it very flexible. Yes, even as a portable SDR it cuts a fine figure.
Due to the compatibility with many control programs, standalone operation and portable use, the LAN-IQ is almost the egg-laying wool milk sow.

Excellent price / performance ratio!

Available from: https://www.afedri-sdr.com/index.php/lan-iq-sdr

posted: 01.05.2020

 

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