gqrx VS nrsc5

There's an issue open for this: https://github.com/gqrx-sdr/gqrx/issues/1104

I could really use some help from a software build expert. Gqrx and all its dependencies would need to be built in CI with Apple silicon support, and I don't know how to do that.

If you don't need the web interface and your usual desktop SDR software supports rtl-sdr tcp mode, you can easily set up a small board that calls rtl-sdr with the appropriate parameters so that it will wait for a remote connection from the above software, not unlike what happens with WebSDR, but you would be using your usual desktop SDR application which would be native and much more snappy than a web browser. Here's an example using gqrx.

https://www.youtube.com/watch?v=74jDcHuDCmE

https://gqrx.dk/

GQRX works pretty well for me. There is also CubicSDR and SDRAngel afaik - you might just want to play around with them and see which you are most comfortable with.

SSB/CW (also (W/N)FM/AM/Raw) using GQRX

For most signals (including analog AM and FM modes) you can use a laptop with an RTL-SDR USB dongle (fairly cheap), or another SDR, and a reasonably tuned antenna. Various RTL-SDR models can tune from around 500 kHz up to 1.75 GHz with 3 mhz of bandwdith, and works with free software like SDR# for Windows and GQRX for Linux. It works with lots of other software, too, for ham modes, digital modes, etc.

Some of the Crossfire modules have a rudimentary spectrum analyzer function on them that might help you identify if there are other devices operating in the 900MHz band around that area, but I'm not sure the nano TX is one of them. I have a couple RTL-SDR dongles or equivalent I'd use with GQRX as a cheap spectrum analyzer if possible.

Good old GQRX for me https://gqrx.dk/

There is loads of software that will work such as SDR++, GQRX, CubicSDR, and SDRangel just to name a few. For HD radio reception, there is nrsc5. Nrsc5 only works with an rtl-sdr, so you will need one if you want to receive HD radio.

That decision was made by the original author (Andrew Wesie), but I think it makes sense because nrsc5 only needs a tiny fraction of the functionality that GNU Radio provides. Implementing the functionality directly in nrsc5 avoids the need for a large and complex dependency.

One downside is that we don't get the broad hardware support that GNU Radio provides, but maybe we'll someday take another crack at integrating SoapySDR. (See https://github.com/theori-io/nrsc5/pull/131 for an earlier experiment with that.)

That's HD radio, the sidebands are digital audio. It can be decoded with nrsc5 and an rtl-sdr.

An article called "Decoding and Listening to HD Radio (NRSC-5) with an RTL-SDR" links to a security researcher's write-up called "Receiving NRSC-5" about how they wrote the software to do it. That links to the actual nrsc5 software on GitHub.

There is loads of software that will work such as SDR++, GQRX, CubicSDR, and SDRangel just to name a few. For HD radio reception, there is nrsc5. Nrsc5 only works with an rtl-sdr, so you will need one if you want to receive HD radio.

In theory could https://github.com/theori-io/nrsc5 be listening to all hd radio at once?

HD Radio is closed and proprietary, but there is at least one FOSS receiver out there: https://github.com/theori-io/nrsc5

NRSC5 is a decoder that I use. If you are on windows there are a couple of extra steps you have to take compile it, but it works well! They have a newer one with a GUI that can also display album art.