Viewing profile — argilo

An SDR's sample rate only limits its bandwidth. Most devices include a mixer, which allows the transmitted or received signal to be shifted in frequency by an amount much larger th…

It's definitely possible to transmit multiple TV channels at once, and I have experimented with that in the past. Since TV channels are 6 to 8 MHz wide (depending on what part of t…

The cars on the map are the locations of people who are hunting for balloons after they have fallen back to earth. SondeHub's "chase mode" allows you to announce your position so t…

The code of nrsc5 (and my transmitter project, https://github.com/argilo/gr-nrsc5 ) would be the best source of information for the undocumented parts. I do have some private notes…

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 …

I am also the maintainer of Gqrx and I would love for it to have a built-in NRSC-5 receiver. The trouble is that some aspects of NRSC-5 are still patent-encumbered, which makes sof…

Most of the details are available in the specification, which is available here: https://www.nrscstandards.org/standards-and-guidelines/docum... The missing parts are the audio cod…

Also, all of those stream types seem to be used across multiple stations. I haven't seen any weird one-off streams.

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. Impl…

It would only be possible if the tuner exposed raw RF samples, the way RTL-SDR dongles do. I'm not sure whether any of the integrated FM receivers do that.

I'm not aware of any digital-only FM stations either. But there are a handful of digital-only AM stations, like WWFD.

Some stations have "HD TMC" (traffic message channel) streams. The others that I've encountered are "HERE Images" (traffic & weather radar images, discussed and mostly reverse engi…

Also, I should mention that Python is not a requirement. The GUIs that people have created so far were written in Python, but the nrsc5 project itself is built entirely in C, and i…

The documents look to be available here: https://www.drm.org/specification/

Models targeting the SDR market (e.g. from RTL-SDR Blog or NooElec) do have some improvements compared to models sold as TV tuners. Most importantly, they often include a more accu…

I haven't investigated the CPU and RAM requirements in depth, but I have used nrsc5 on a Pi 3B without issue. I suspect a Pi Pico would be too small.

RTL-SDR tuners usually have very good reception between 50 and 1000 MHz, which includes the FM broadcast band. It is easy to overload the analog-to-digital converter, so it's impor…

Yes, it is similar. It is used primarily in North America, while DAB is used primarily in Europe.

It might be possible, but I'm not sure whether a typical router would have enough CPU horsepower to do the processing required to demodulate the signal.

Time information is broadcast, but in my experience it's often inaccurate. There's also a special stream for emergency alerts, but I haven't seen it in use. There are various data …

In addition to files, some stations also send out "stream" and "packet" data. There is ongoing work to reverse engineer the formats. See the discussion here for details: https://gi…

Some stations send out traffic and weather images (as well as album art and station logos). The files can be dumped to disk using nrsc5's "--dump-aas-files" option. A few people ha…

My preferred dongle is the RTL-SDR Blog V3: https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/ They also have a new V4 version, but it requires updated drivers that will take a bit…

I've heard that term as well, but the official site denies it: https://hdradio.com/trademark/

DRM broadcasts are definitely hard to find. A schedule is available here: https://www.drm.org/what-can-i-hear/broadcast-schedule-2/