You can set up an AFE822x Diversity Receiver with PowerSDR for under US$400. Great value and performance to get started in SDR spatial filtering.
My recommendation for SDR software for the AFE822x diversity receiver is PowerSDR. Linrad is another good choice, but more on that later.
PowerSDR was developed as the software client for the original Flex radios. Subsequently, users adapted it to support other gear, especially the HPSDR hardware. PowerSDR was first used for diversity reception with the Flex 5000 containing a second receiver. The feature was called Enhanced Signal Clarity.
The PowerSDR variant you want for an Afedri receiver is OpenHPSDR-PowerSDR mRX PS and you can download the latest version here. After installing the software, use the Afedri Control Box to put the radio into dual diversity mode, and then connect with PowerSDR over Ethernet using the “Hemes” protocol.
It’s that simple. You now have your AFE822x diversity receiver in operation, as shown in the picture above. With the PowerSDR Phasing Control, you can:
- Listen to either receiver independently or sum their signals together
- Vary the phase and amplitude of each channel using the graphic “radar” control. Moving around the circle varies the phase. The length of the vector varies the amplitude.
- Do spatial filtering with a different antenna on each channel.
In the future, I will post some videos of this set up in action. In the meantime, watch this demonstration of PowerSDR diversity reception with the Flex 5000.
AFE822x Diversity Receiver – A Few Niggles
While this configuration with PowerSDR works really well, there are a few niggles. First, PowerSDR does not suppress the DC spike at the center of the passband. This results in a phantom carrier. You can work around this by doing frequency translation within the passband using the Click Tune (CTUN) feature.
Second, as you change bands, the RF Gain setting in the Afedri radio will sometimes change mysteriously. You can mitigate this by keeping the Control Box open and making manual adjustment. I still have not figured out how or why this happens. It’s a minor irritant. Perhaps it has to do with how the “Hermes” protocol interacts with the AFE822x diversity receiver.
Third, for the life of me, I cannot get PowerSDR to send audio to my PC speakers. Fortunately, this gets resolved using the software’s built in virtual audio cable and routing to the speakers.
Finally, and this one is really silly, PowerSDR tuning steps are not mode dependent. You can work around this by setting up band memories with the proper tuning step. Otherwise, change it manually.
Having said this, the AFE822x PowerSDR combination is really good. The software does most things well and is easy to learn and use. And, of course, PowerSDR is open source.
So, mission accomplished. An SDR diversity receiver for under US$400 that works great!