N9EWO SDR Reviews : SDRplay RSP1A / AFEDRI

N9EWO's Review : SDRplay RSP1A "WideBand SDR" (software defined receiver)
(earlier model SDRplay RSP1 was tested previously, now discontinued)

*** What is a "SDRplay RSP1A" ?? / No USB 3.0 on Host PC ***

The SDRplay RSP1A is a fairly low cost SDR (Software Defined Receiver) "computer connected" device that features full radio spectrum coverage without any silly converters getting in the way. One SMA antenna connector for all ranges. RSP1A indeed touts a 14 bit architecture, but in reality uses the same ADC chip in the elder non A version. As one increases in frequency this gets reduced down to as low as 8 bits.

There is even decent front end band-pass filtering inside its semi-smooth plastic box and is improved with the later tested A version. Also added is a switchable MW/FM (and DAB for Europe) notch filters that work well. If one lives near powerful MW or FM broadcast station, this could be a major plus (when tuning outside the MW / FM bands) without any add on filters to have to fiddle with.

Power is supplied via the host computer USB port via a USB cable, so no additional external power supplies are required. Low current consumption is around 185ma (vs. around 150 ma for the non A version).

Operates with many operational platforms offered makes for a nifty Android SDR as well (not tested, requires Java with Android). In our testing here we will be limiting the scope to Windows 7 operating systems only (64 and 32 bit). Sorry, we did not test this device on any other Windows OS (Windows 8 or above) or platform.

"Important Note" using USB 3.0 (as experienced in testing) : We had no luck using the RSP1A with a USB 3.0 socket on the test PC. It installed the API-drivers when connected, but did not allow operation (could not find it after). Yes USB 3.0 are supposed to be backwards compatible. As soon as we switched to a 2.0 socket it worked fine. Appears most have not had problems here, so perhaps a PC driver issue in our case ? We were unable to find out why this was happening (the 3.0 port working properly with other connected devices) ?

*** USB Cable Chokes “To Be Or Not To Be ?” ***

Any new owner needs to supply the proper high quality "SHIELDED" USB cable (good idea to keep it under 3 meters in length) and a connecting antenna cable. The SDRplay folk’s recommend that a USB cable be a shielded type (not all are) that has chokes on either end be used to help keep radio interference reduced.

In our testing we could tell no difference with more or less interference (using outdoor antennas with coax feed line) using a standard (non shielded) USB cable with and without the ferrite chokes . This was with a laptop computer or Desktop, cable length under 6 feet. Using with any indoor antenna, this could be a different story ?

But of course this will depend on YOUR situation and no 2 are going to be the same. As they say the shorter the USB cable the better. I would say better quality cable 6 feet (around 2 meters) or less length.

*** Genuine Plastic Case / Cool Operator ***

The RSP1A is still housed in a plastic case , but on the inside now is a sprayed on metallic paint coating. It appears to help with household noise, but not by a major difference in our testing.

Aside from that it is in a most sturdy “plastic box” about the size of an over sized Klondike Ice Cream bar. It is held together with 4 screws, so no heat welded or glued together cases here.

We stuck 4 SMALL soft plastic "stick-on" feet on the corners of all test samples so to eliminate the very light cabinet from sliding around. Please Note : The plastic with the RSP1A was slightly more rough, which made it a bit more difficult for the adhesive with some plastic "stick-on" feet to stick properly. We found these clear 3/8 inch "Shepherd Hardware Products" number 9964 feet to hold properly (Menards and other stores in the USA). As it normally goes with these, please let it sit undisturbed for a good 24~48 hours after application for the adhesive to set.

At one time there was a after market ALL METAL case sold by "RTL-SDR.Com (fit the original RSP1 or newer RSP1A) for about $ 25. USD. We tested one of these and our findings can be found in a separate section at the bottom of this page. Sadly this case is no longer available.

There is a female SMA antenna connector (early versions used a female F fitting) and connection to the computer is via a B type USB socket. Certainly a much sturdier connector being used here say over a Mini or Micro USB.

Being in operation for hours, the case remained cool (only ever so slightly warm). The elder RSP1 model is not using a TCXO (uses "internal" crystal in the MSi2500 MIRICS chip), but overall stability appeared to be most adequate.

With the RSP1A a "0.5 ppm" TCXO was added which made only 4 Hz off frequency (at 20 MHz) before any fiddling. But not that the test sample of the RSP1 was a slouch for stability (it is decent). There is tweak for the reference oscillator in both versions for off frequency adjustments in the EXTIO. Some SDR programs provide a way to adjust this as well (like with HDSDR and SDRuno).

*** Full DC To Daylight Coverage ***

RSP1A receiver coverage is from 1 kHz right up to 2 Ghz with no gaps (RSP1 started a bit higher at 10 kHz). Even the taboo 800 MHz frequency segments in the USA are covered (not that there is anything non digital to listen to there..there isn't).

*** Host Computer : Dual Core OK , but best with a FAST “Quad Core” Processor ***

Yes, one can use the SDRplay RSP1A (Microsoft Windows computer) with a more limited “Dual Core” processor around 3 GHz at say 4 GB of RAM (Memory) and only using a limited scope bandwidth (2 MHz sample rate, IF Bandwidth at 1.536 MHz or less). This is what was used for testing in this report in fact.

The slower the computer the worse the performance / dropouts and even lockups are possible. Any additional programs running along with it makes any limited computer recourses be even worse. Don’t even think of using an old "single core" computer at any speed, you will probably be disappointed (if it works at all).

As it always goes with computer software/hardware, this will vary with the SDR program used. Connected to a speedy 3.0 GHz QUAD core computer and say have 8 GB of memory, it will be dropout / doggy free and the user will be a happy camper.

*** Driver / Tested Software (using "Windows 7" 64 and 32 Bit)***

Mirics API Drivers

The Mirics (API) / SDRplay drivers is the software that needs to be installed before the USB cable is installed for use with ANY software. No installation issues at any time with 4 different Windows 7 computers in testing. API-Driver version tested was 2.13.1. EXTIO version tested up to 1.2 (4.2 with the RSP1).

NOTE : SELECTED SDR Programs come packaged with the SDR Software / API driver and EXTIO install which makes it much easier to install.

IMPORTANT : At the end of the HDSDR "Package" installation, be sure and allow the HDSDR program to be accessed so the EXTIO part of the installation will be properly installed (will ask / point you for the right EXTIO version / hardware, DO NOT let it reboot when you see the prompt...continue on). If this is not done, errors will appear as the EXTIO will not get recognized.This is also valid with the "EXTIO / Driver" standalone version (with no SDR software) that can be downloaded on the SDRplay website (at the time this text was added).

OPERATION SDR SOFTWARE

The 5 FREE software packages tested for this report were (in order of our ratings) :

1. - SDRuno Version 1.22 / 1.4.2
2. - HDSDR Version 2.76a / 2.80
3. - SoDiRa Version 0.100 (Preview 31)
4. - SDR# (SDR Sharp) Ver 1.0.0.1361 (1361) - (RSP1)
5. - SDR Console (V2 tested only with RSP1)

1 . - SDRuno (Version 1.22 and 1.4.2 tested) *** Top Rated ***

SDRuno is the mother ship software first time we tested this was still in its early stages (version 1.04). 1.22 installed with no problems and a EXTIO is automatically done (no EXTIO is required at all for the 1.3 version and above).

We found version 1.22 to be excellent. It does take time to adjust to the "multi screens" and unusual layout, like user set menu's are all over the place (not just in one spot). But after awhile it's not a drawback. Two VFO's was good to see, however they do not store the mode/bandwidth (are the same between them). Memory channels do store mode, bandwidth and tuning step along with a alpha tag.

Excellent GUI overall, including a decent "faux" florescent frequency display and nifty looking analog edgewise s-meter. It does have the most adjustments of any program tested in the lot (expect for the spectrum scope). One can easily select Spectrum Scope or Waterfall or both. Good direct keyboard entry was appreciated as well as the provided band preset buttons. Very handy muting feature, with volume adjustment on the GUI.

Supports FM Stereo and RDS (both work excellent), plus the S-meter accuracy is one of the best ever tested on a SDR device by the author (plus it requires no calibrating at all). Recorder is for IQ "spectrum" recording only. One will have to use a add on program such as Audacity for audio recording (no biggie).

So yes SDRuno makes to our top pick for general use.

Version 1.4.2 Excellent with a MAJOR Caveat

- 1.4.2 verson of SDRuno came out on Novenber 16, 2020 . New Version 3.07 of the API/HW is also included in the SDR Uno version 1.4.2. The version 3.07 API/HW will NOT work with earlier versions of SDR UNO. IMPORTANT NOTE : You also CANNOT have 3.06 and 3.07 co-exist on the same PC.WARNING : As of this text being typed API/HW 3.07 does NOT work with other SDR programs. So HDSDR and SoDiRa etc. will no longer function (hopefully this will get fixed in time with both programs ?) . As indicated you are not able to have 2 versions of the API/HW driver loaded on a PC (cannot co-exist). We have tested the version 1.4.2 and must say it is much improved over the old 1.22 we were using. Now also supports plug ins.

Version 1.22 was also the top with DSD Plus in our testing (more later in this report). Also worked equally well with 1.4.2.

2. - HDSDR (Version 2.76a / 2.80) *** Top Rated ***

(click on photo for screenshots)

Installed with no problems and easy to use. EXTIO plug in is required after installation and before use with HDSDR.

Spectrum scope colors (but not easy to do) and all of the important adjustments are there and EASY to use and understand. Does have a nice looking S-Meter, it over reads at default settings however there is a easy way to calibrate it. Direct keyboard entry is provided but a bit confusing to make work for newcomers just as with SDR Console (but not bad after adjustment to GUI).

One can adjust to even turn off the waterfall and or spectrum scope (or change the displayed sizes from default, but is not obvious). Text as taken from the old Winrad V1.32 manual (which is still useful to get started with HDSDR as it's based on that) :

"The upper window is divided into two panes, the waterfall and the spectrum. It is possible to choose how to assign the available space between the two panes by using the right mouse button. Just place the mouse pointer on the frequency scale. The pointer will change shape, indicating that you can drag left and right the portion of the spectrum that is displayed (keeping the left button down) or you can drag up and down (keeping the right button down) the frequency scale which divides the spectrum from the waterfall. Much more complicated to explain than to do…". Just be sure when you adjust this that the receiver is in operation.

If you only desire the Spectrum Display using these adjustments and then desire the frequency indication ruler on the BOTTOM like I did (not on the top), then set in Options > Visualization > Swap Spectrum / Waterfall Position . Another important spectrum display user note , by hitting C on the computer keyboard will CENTER the receive frequency (excellent feature).

Features include: Noise Reduction, IF and RF Noise Blanker, Manual and Automatic Notch Filter, AFC. Excellent ECSS that holds lock very well and operates on both sidebands or LSB or USB (selected in a 3 loop cycle by left clicking the mouse on the ECSS button). ECSS does add bit of bass kick to the audio. Built in recording interface that records the spectrum or audio (right click on the RED record button to configure). Even includes a scheduler as well. Sadly it does not offer FM Stereo but it does have memory storage ("FreqMgr" icon) and quick band presets. Even can download and import the latest EiBi data.

DRM with the DREAM software (and Virtual Audio Cable, same as with DSD+) worked quite well in our tests with fairly easy decode. HDSDR has a Digital mode that presets everything to make it easier. But this offsets the frequency for some strange reason so we had to move it a bit to make work (tested with Radio Kuwait on 15540 kHz).

Dream Update : Sadly the Dream software is no longer usable with most DRM broadcast as I type this text. The program is lacking the xHE-AAC Codec that most DRM broadcasters are now using (you will decode nothing). We hope that this major bug will get corrected in time ?

Using it with DSD+ is mixed bag with 2.76a, but for some reason was improved using with 2.80 beta11. Depends greatly on settings as it does with any of them, but here is a bit more finicky (but overall works OK).

With the new 2.80 beta11 version : Adds "Band selection" and "frequency step selections" on main window (excellent as it also stores the mode and step with these presets). Auto-LO option and keep Tune when LO is changed are also 2 additional and welcomed features.

HDSDR uses the least computer resources to operate out of the lot (it's actually now a horse race with SDRuno version 1.22 in our later tests). If you have an older slower (dual core) computer that chokes with the others, this is the one you should try. Is really the ONLY one that will work with the elder Windows XP OS. Overall is a winner for overall use and performance. It’s simple, sounds good, fun and recommended for anyone starting out using a SDRplay RSP1 (or any SDR). Great program to get your SDR feet wet and learn the ropes and for general use after.

3. - SoDiRa (Versions .099 and 0.100 , Preview 24, 25 , 27, 29 , 30 and 31)

(click on photo for screenshots)

Not the most feature packed application (it's not) , but Bernd Reiser's "SoDiRa" does not only decode FM Stereo BUT C-QUAM "AM STEREO" as well. During skywave nighttime conditions (at the time this text was added), we received CFCO in Chatham Ontario (Canada) on 630 kHz in beautiful AM STEREO. This of course would also work in the SW part of the spectrum for that "pirate" that may show up using AM STEREO (which has indeed happened over the years). This program requires a EXTIO just as with HDSDR.

It indeed has built in DRM (no separate Dream program required). But takes a MUCH stronger signal over using HDSDR and Dream in our testing. In fact its more like near useless in North America with DRM broadcast near "nada". Using the Dream software separately with SoDiRa (with the here VAC of course) also performed MUCH better over it's built in decoder ! (DRM UPDATE : DRM reception is not normally possible anymore, either with the SoDiRa's built in decoder or even with the Dream software. Most DRM broadcasters now use the new xHE-AAC codec and is not properly supported as I type this . A "loose-loose" situation for all here !)

Decent ergonomics and logical layout, but as with all SDR GUI's, there is a learning curve. Decoding has Simple and Universal decoding selections (please remember that default is selected for NO decoding). No easy volume adjustment on GUI which is a bit of a disappointment. As normal with any of them, FM "Wide" Broadcast reception takes more computer resources. But overall it's winner again including it's built in AM STEREO decoding (also has decent selectable sideband Sync Detector as well). It worked excellent with the separate DSD+ decoder too (see more below on this subject).

NOTE : Version .099 (which is included with the 0.100 previews up to 28), was unstable in our tests. Preview 26 was not usable (it blew up right from launch, but was fixed quickly with Preview 27 and even better in 29). Older versions are NOT archived on the web site. But overall this is a very easy to use SIMPLE program and we liked it. Hopefully improvements will continue. A most worthy program, excellent job Bernd !

Important Updates : Via user reports, 3.03 API/HW (driver) and above does NOT work with SoDiRa (not tested). Preview 32 was NOT usable with the AFEDRI SDR (see separate review below, Preview 31 worked fine). Bernd has informed us this has been fixed but we have been unable to make it work with the newer API's (still API errors). Anyone have better luck here ?

4. - SDR# (SDR Sharp) (RSP1 only)

This program was tested with the older original RSP1 version. An older version of SDR# (SDR Sharp) was required to operate, version 1361 (1.0.0.1361). Also a older EXTIO version 3.7 MUST be used with 1361 which is not easily found anymore (do your own searches). It is common knowledge that more current versions of SDR# do not work well with SDRplay RSP1 (if you can make it work at all).

Worked well enough and enough adjustments to satisfy most folks, easy to figure out. Not the easiest to deal with changing frequencies, but has a useful memory window and that is easy to enter and edit. We found the Spectrum scope not to be so user friendly or eye pretty (or usable for that matter), but is big and one can turn off the waterfall. Sadly the SDRplay RSP1 does not work with any of the SDR#’s extensive plug Ins.

Program has no S-Meter and only very limited color changes possible on the spectrum scope. Works adequately with DSD+ with the Virtual Audio Cable. Even with this working OK with the SDRplay RSP1 OK, it was not left installed after testing. It does support FM Stereo where HDSDR does not.

5. - SDR Console (V2 - Tested with RSP1 only) *** Program Good , But Bottom Rated Because of Expiring Scheme ***

Was the easiest to use and most appealing GUI. Easy to install and to get up and running. No other software (EXTIO) was required for operation aside from the API and SDRPlay drivers.

SDR console V2 at the lower spectrum bandwidths were most usable provided nothing else was running in the background with a lesser computer. In fact it was the second runner up for using the least computer resources to operate. Supports FM stereo plus RDS.

Memory operation (V2) was straightforward and useful, however direct frequency entry was quirky / difficult and sometimes locked up the program. Important tip : Be and enter the proper leading zero’s (a pain). Features include: Noise Reduction, Noise Blanker, Manual and Automatic Notch Filter, Double Sideband AND LSB / USB "Synchronous Detection / ECSS" which holds lock well. Excellent AGC (Fast-Med-Slow) with adjustments. "Span" adjustments were first rate.

A huge downside and the reason it was BOTTOM rated, as this report was being complied , “SDR Console” uses an expiring license scheme. So whatever version you are using it turns into pumpkin sooner or later. Not a good scenario here in our view (in fact this is totally unacceptable to the author). We did not test the RSP1A with SDR Console (V2 or V3).

*** Generally Great Audio and AGC Performance ***

Audio quality was decent with all tested programs. We wish there was at least say a 5 band EQ adjustments in these programs to tweak audio frequency response a bit (included in standard software, NOT having to use a plug in) . However many sound card / drivers allow for limited bass / treble tweaking.

To our ears the AGC was tested as excellent with all programs. Sync detection helping the cause greatly with AM mode "HF fading" distortion. If any transmitted signal contains distortion, the RSP1A will let you know.

*** Dynamic Range / Sensitivity and General Performance ***

To make matters more fair we compared sensitivity with our original RSP1 sample using a standalone Yaesu VR-5000 wideband receiver. For my review on the discontinued Yaesu VR-5000 (click here).

Testing (ears method) here was done only with SDR Console V2 at default settings (which we found out are the best settings to use) :

- LNA turned OFF
- RF Gain at –50db
(other settings in the Mirics API also at Default)

Antenna’s Used (for both receivers) :
- SW/HF Outdoor Antenna : 55 foot RF Systems MLB (long wire)
- VHF/UHF Outdoor Antenna (above 30 MHz) : 19 inch ground plane at 25 feet height.

Dynamic Range : While tuning the ShortWave / HF bands “Dynamic range” (overloading) was never experienced during the testing period with the SDRplay RSP. It behaved itself very well even in the 49 Meter band at night. No FM Broadcast overloading either.

Receiver Noise : SDRplay RSP1 was the overall winner here. But in some areas the Yaesu actually won the battle.
Selectivity : Of course the SDRplay RSP1 blew away the Yaesu VR-5000 here , no real comparisons required.

***** Sensitivity Winners (RSP1 model as compared to the long discontinued Yaesu VR-5000) *****
(very weak signals and audio recovery, mode and bandwidth setting changed as required) :

- MW / AM Broadcast : Yaesu VR-5000 (SDRplay RSP1 was OK on MW , but the VR-5000 was the clear winner even with it’s attenuator on)
- SW 11 Mhz : SDRplay RSP1 (by a hair). Signals were about equal, but the lower noise floor made recovered audio from the SDRplay wins easy here, especially with the Sync Detector on.
- FM Broadcast 93 MHz : Equal. Perhaps a very slight edge to the SDRplay RSP1. But it’s pretty much an even showing here.
- 162 MHz : Yaesu VR-5000. Audio was heard better from the Yaesu here for some reason, but a near equal signal on SDRplay was present. Another close one.
- 450 MHz : Near Equal. S/N goes to the SDRplay here.

In general it’s a very sensitive device, just as much as the elder Yaesu VR-5000. Of course the overall performance edge has to go to the computer connected SDRplay RSP1. But the elder Yaesu VR-5000 held it’s own. The Sync Detector with SDR Console works fantastic. Double sideband ECSS or just LSB or USB selections. Holds lock with even signals that are near into the noise.

*** Spurious Signals Issues ***

Some users have reported STRONG local FM Broadcast signals bleeding (overloading) into other parts of the tuned spectrum with the original SDRplay RSP1. We did not experience any of this at our test location. Any image signals were also absent at the test location. Please note, we do NOT live in a large metro area with excessive broadcast signal levels. Of course the RSP1A has bandpass filters to help tame FM broadcast signals, where the original RSP1 did not..

*** "DSD Plus" Program (see our set up information on the bottom of this page)***

OK….we normally only cover Short Wave / HF part of the radio spectrum here with any reviews, but in this case we just had to try and make work the DSD+ program with the SDRplay RSP1A.

DSD+ is a popular Windows Computer software program used for decoding digital speech such as P25 with SDR receivers. With the tested version 1.101, includes an event log that shows call target and source ID history and an audio waveform screen, which can help determine if DSD+ is receiving audio correctly (a very useful feature as we found out). Has the ability to decode the following digital modes (and is automatic too). Please make note the DLL's are downloaded separate and when unzipped are placed into the same directly as the program files.

• D-STAR
• NXDN4800
• NXDN9600
• DMR / MotoTRBO
• P25 Phase 1
• X2-TDMA
• ProVoice

It can be used as stand alone program as well. In other words one can take a stand-alone scanner receiver, tap the discriminator audio output and feed that into the computer (line and or Mic input jacks). But in our case we desired to use the same computer that hosts the SDRplay RSP with the DSD+ program. To do that the use of a Virtual Audio Cable (VAC) is required. We used a FREE donation-ware version.

After installation of the VAC and with certain adjustments and procedure (whew!!), it performed adequately espicaly with SDRuno and SoDiRa. This program decodes digital modes that are not covered on most standalone scanners as well. Trunking is not normally possible with only "one" SDR receiver. Success depended on the software used as well as careful adjustments (especially when using HDSDR which required higher levels).

That is the stinker with making DSD+ to work with the SDRplay RSP1A, frustrations and hours in the battle of setting it up. Provided below are my PERSONAL notes what I did to make it function. This of course it cannot cover everyone’s situation (computers, sound cards etc), so treat this only as a base. Some parts may be more my feelings and not facts.

Please keep in mind these tests were done using a Windows 7 “DUAL Core 3 Ghz” computer with 4 GB of memory. Your experiences may vary and could (should) work better with a more zippy and QUAD core processor computer? More memory does not hurt either (say 8GB). Again when using the SDRplay RSP1A (and especially with DSD+ in the mix) with a lesser computer one should not have ANY other applications running. Otherwise decode dropouts and other nastiness are possible with any of them.

IMPORTANT NOTES : Of course use FM mode (with no filtering) at around 15~20 kHz bandwidth for most digital modes. Setting of the VAC audio level is extremely important. If it's too loud or too soft, decoding will be choppy or even not at all. So watch your audio level (metering bar on the VAC in the Audio Properties).

So our the Preference list for the best program using DSD+ with the SDRplay RSP1A :

(SDR# [SDR Sharp] was not included in these tests as it is no longer available for the A version) : Was not tested with SDR Console but that program was good with the non A version test sample with DSD+).

1. SDRUno. Plain and simply the BEST decode and near zero dropouts with enough computer horsepower. (Remember the FM filtering needs to be turned off).
2. SoDiRa. Works good with DSD+ (pretty even with SDRuno).
3. HDSDR. Most usable. Only minor dropouts after a bit of level tweaking.

*** Final Word ***

The SDRplay RSP1A is clearly the winner in its price point for a REAL SDR device plus for DC to daylight frequency coverage. Gives for greatly increased performance when compared to those under $ 50. RTL-Dongles that we see sold all over the place at time this report was compiled. The improved front filtering with the A version is a nice improvement plus the added TCXO for a more accurate frequency display (before any tweaking). SDRuno was extremely desirable program after one gets used to it. It also works very well with DSD+ once set up PROPERLY (and with adequate computer horsepower).

Dave N9EWO
© N9EWO, all rights reserved
Ver 9.9

Our sincere gratitude to Hal H. as he made this "AFEDRI SDR Net " review possible.

The decent AFEDRI SDR NET Software Defined receiver. Rev 3.0 Tested (with it's optional Hammond metal cabinet)
Even now a bit "long in the tooth" (12 bit device), it's one of the few SDR's available that includes a LAN connection.
(around $ 250. USD with the case as this report was typed, not including shipping from Israel) (N9EWO Photos)

Approx. Serial Number of Test Sample : 353263xx (HF Version)
Board Version : Rev 3.0
Firmware : V.1035
Country Of Manufacture : Israel

Tested With Software :
- HDSDR : Version 2.80
- SoDiRa : Version Preview 30

Test Antenna's :
- RF Systems MLBA-MK2 long wire (55 ft length - 24 ft height at peak)
- Comet H-422 Dipole (24 ft height - Straight Configuration)

Tested Accessory : Chinese 3.5 to 30 MHz “Band Pass Filter” (PL-259 connectors)

N9EWO's Review : AFEDRI SDR NET (software defined receiver) 0.1 to 35 MHz ShortWave Version, Standard Configuration with BNC connector. (NOTE : Test sample was a older Rev. 3.0 version. There should be no major performance differences with current production units.). Versions are also available that offer 100 kHz to 1700 MHz coverage and "Dual Channel" operation (not tested).

PRO :
- USB 2.0 or LAN "Network" operation.
- Optional BNC Female Antenna Connector on Request, no extra charge (nominally a SMA female).
- Comparable Decent Sensitivity to the RSP1A and other standalone HF receivers (side by side comparison testing).
- Easy FE and RF Gain Adjustments (see con).
- Robust (optional) Hammond Metal Cabinet with Stick On Soft Plastic Feet.
- The 2 very annoying front panel LED's can be turned OFF (needs to be done every time it's powered up).
- Powered via 2.0 USB or External Power (see con)

CON :
- Pricey for It's age.
- Local MW Station Breakthrough Into Entire SW Spectrum (Lacks Front End Filtering).
- Limited Dynamic Range. Even with MW Breakthrough fixed with Added Bandpass Filter, can still overload (this is not a serious problem, see text).
- FE Gain Adjustment Of No Use (keep at Minimum 1.00, go no higher !).
- Fairly High Current Consumption at around 460 ma (from Host Computer via USB or External Power).
- Limited 230 kHz Spectrum Scope Range when using USB connection (Rev. 3.0).
- Lacking TCXO (but has most adequate stability).
- Firmware updates are not for the faint of heart and use the LAN connector and external power (Note :Some batches of "Rev 5.2" PC boards and above are missing parts and until those are replaced firmware updates are not possible).
- Reports have indicted more receiver background noise when the LAN-Network cable is used (not tested, see text).

The AFEDRI SDR NET receiver with the all metal Hammond case (optional and recommended) is one solid robust device and sized at 4.7 length x 3.07 width x 1.18 thick inches large (120 x 78 x 30 mm). Operational power is via a "short" MINI USB cable or via external power with it's 2.5 mm x 5.5 mm DC input socket (please note again is using a 2.5 mm center pin, NOT 2.1 mm). For most later and current samples the extremal DC power requires a strange 7.5 volts with some hefty current requirements, When powered via USB 2.0 port (sorry no 3.0 support) it just makes the under the 500 ma limit. It actually comes with a DUAL plug USB cable, but to use that is only normally required with the HF-VHF and other versions where the current draw is near 800 ma's (not tested). A better quality "single plug" 3 foot MINI USB cable worked perfectly in testing with no issues (this could very depending on the host PC and your cable). We did not test the receiver with the LAN connection.

It's architecture uses more traditional SDR "Direct Sampling" innards that includes use of a FPGA and internal microprocessor. It does not use a compromise TV Tuner chip as does the SDRPlay devices. Once the USB cable is inserted (Important : All LED's are ON before ANY SDR program is started) Windows automatically installs the required drivers. You will also see a added AFEDRI Audio "Line" item added in the Recording devices (sound card, see the manual for important information here). 3 LEDS are located on the front panel : RED for Power, YELLOW for Front-end IC initialization / input ADC overload (flashes when overload occurs) and BLUE (constantly flashing) that the front-end IC is functioning properly, including all electronics. The YELLOW and BLUE LED's can be turned off if desired (WHEW !). But this needs to be done every time the SDR is powered up.

Tip : When the host computer is placed into standby/sleep mode, be sure and physically disconnect the AFEDRI from the USB or LAN port BEFORE. Otherwise It will not restart properly. If you forget just remove and reinsert the connecting cable (SDR Program not being restarted until all three SDR's LED's are back on).

Antenna jack is normally a female SMA type. However if one desires at time of purchase a female BNC can be substituted (no additional charge ?), which our test sample had.

“SDR Network Control Box” is actually a EXTIO with a few other files as well. As usual these are all imported into the SDR's program root directory.

There are 2 Gain controls provided in this interface. The “FE Gain” knob controls the “digital” gain of DDC (inside AFEDRI8201 chip). It has a range from 1 to 4 with a red digital indication. MOST IMPORTANT : We found it was best to keep this at 1.00 MINIMUM level FULL TIME. This application also provides many other adjustments including the LAN network settings.

The “RF Gain” is for controlling the gain of an input Variable Gain Amplifier (which they call VGA) of the SDR. Another red digital indication next to the adjustment. Found it was best to just keep the AGC check marked (ON), except at night when overloading hits or for other STRONG signals.

“SDR Network Control Box” GUI (EXTIO)
The samples serial number and current firmware is also located in "About" tab. (N9EWO Photo)

Lack of front end filtering is a MAJOR drawback with the AFEDRI SDR. It only has a lone 0 to 35 MHz bandpass filter (standard version). So if the owner lives near a powerful MW station and using a decent resonant antenna (as at the test location), the SW station you are trying to hear can be mixed with mishmash of your local MW station. This issue was cured by using a (approx) external 3.5 to 30 MHz bandwidth filter (see photo below). However that does not cure it's modest dynamic range and during "peak signal" nighttime listening conditions can be another problem. Good news is this it not a serious issue and usually cured with a slight reduction of the RF Gain control (turn off the AGC check box). But nevertheless is a minor bug that can creep in.

Overall the sensitivity is decent and comparable to the RSP1A and even to the Icom IC-R8600 tabletop set (preamp off) using the same antenna in direct side by side comparison testing.

Chinese 3.5 to 30 MHz “Band Pass Filter” with SO-239 connectors (check on ebay or amazon).
Depending on where you live and antennas used , this may be a required purchase for the Afedri SDR.

Spectrum scope has a maximum bandwidth of 1.85 MHz when the LAN port is used (Rev. 3.0, 2.3 MHz with Rev. 5.0 and above). With the USB connection is used it's at 230 kHz maximum.

Reading reports around the internet that when the LAN-Network cable is used, excessive receiver noise floor and spurs can SOMETIMES occur vs. when ONLY using the USB cable for operation. Of course there are many reasons why this could happen. Another possibility is covered in the owners manual that earlier board rev's used a internal SWITCHING POWER SUPPLY. NOTE : Only the USB type connection was tested and did NOT experience any excessive noise issues at the test location. ANY connected external power supply should be of a clean regulated linear transformer type (if you are using a separate switching type supply either with the external input or in the USB input .....good luck !). Of course ones host computers 5 volt output can be extremely variable as well for added noise (this is a switching type supply too). Oh yes we cannot forget that most (if not all) routers are very dirty RF birds, the device itself and IT'S switching power supply !

Manual Excerpt :
"Attention!!! AFEDRI SDR-Net 2.1 and down have switched DC/DC converter to connect to external power supply (this was done to decrease power dissipation). Because there is switched DC/DC converter that is working on 930kHz frequency, so there interference is possible on this frequency or its harmonics. Beginning AFEDRI SDR-Net rev.2.2 it has linear power supply it does not have interference from embedded power supply."

Firmware updates are offered at times on the AFEDRI web site. It's requires use of the LAN port and a bit of expertise to get properly completed (not tested).

HDSDR and SoDiRa SDR programs were tested and operated the AFEDRI excellent with no issues. With the SoDiRa program one needs to be sure the Input sample frequency is set at 192K. This is the ONLY SDR program that can receive AM Stereo (as rare as that is these days). Of course there are many other SDR programs available that will work with the AFEDRI including SDR UNO (not tested). See the SDRPlay RSP1A review above for more information on software.

We enjoyed the AFEDRI SDR NET. It's performance is very good even with it's MW breakthrough and once in awhile dynamic range issues (both easily dealt with). The SDRPlay RSP1A as tested above indeed has it's merits including greater bandwidth (Spectrum Scope) and still using a USB connection.

For it's age it is overpriced, but if one desires a LAN connection on a SDR the AFEDRI is one of very few that offer this. It can be purchased direct via Alexander Trushkin in Israel.