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Re:Listen to HD radio with a $30 RTL SDR dongle by shane350 on Monday November 06, 2023 @12:13AM (#38159113)
This is actually extremely useful when hooked up to a laptop for traveling, because of the embedded traffic information and maps in the sideband data.
Re:Listen to HD radio with a $30 RTL SDR dongle by ghotli on Monday November 06, 2023 @12:26AM (#38159184)
If you're willing to share more on this subject, color me interested.
Re:Listen to HD radio with a $30 RTL SDR dongle by argilo on Monday November 06, 2023 @12:34AM (#38159229)
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 have built GUIs that display the information in a more convenient way:

https://github.com/cmnybo/nrsc5-gui https://github.com/markjfine/nrsc5-dui https://github.com/KYDronePilot/hdfm

Re:Listen to HD radio with a $30 RTL SDR dongle by argilo on Monday November 06, 2023 @12:42AM (#38159286)
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://github.com/theori-io/nrsc5/pull/308
Re:Listen to HD radio with a $30 RTL SDR dongle by westurner on Monday November 06, 2023 @12:48AM (#38159316)
Are there yet Clock, Weather Forecast, or Emergency Alert text data channels in digital FM radio?

FWIU there are also DVB data streams?

Re:Listen to HD radio with a $30 RTL SDR dongle by argilo on Monday November 06, 2023 @12:56AM (#38159352)
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 streams, but not DVB.

A lot of the details are described in the standard: https://www.nrscstandards.org/standards-and-guidelines/docum...

Re:Listen to HD radio with a $30 RTL SDR dongle by westurner on Monday November 06, 2023 @01:26AM (#38159492)
DVB-T could technically carry clock, weather forecasts, and alerts as text data feeds.

What needs to be done to link WEA Wireless Emergency Alerts with HD radio data streams? WX radio could possibly embed a data channel? If it doesn't already for e.g. accessible captioning?

DVB-T: https://en.wikipedia.org/wiki/DVB-T :

> This system transmits compressed digital audio, digital video and other data in an MPEG transport stream, using coded orthogonal frequency-division multiplexing (COFDM or OFDM) modulation.

From https://www.rtl-sdr.com/about-rtl-sdr/ :

> The origins of RTL-SDR stem from mass produced DVB-T TV tuner dongles that were based on the RTL2832U chipset. [...]

> Over the years since its discovery RTL-SDR has become extremely popular and has democratized access to the radio spectrum. Now anyone including hobbyists on a budget can access the radio spectrum. It's worth noting that this sort of SDR capability would have cost hundreds or even thousands of dollars just a few years ago. The RTL-SDR is also sometimes referred to as RTL2832U, DVB-T SDR, DVB-T dongle, RTL dongle, or the "cheap software defined radio"

From https://www.reddit.com/r/RTLSDR/comments/6nsnqy/comment/dkbv... :

> [You need an upconverter to receive the time from the WWV shortwave clock station on 2.5, 5, 10, 15, and 20 MHz] http://www.nooelec.com/store/ham-it-up.html

From https://news.ycombinator.com/item?id=37712506 :

> TIL there's a regular heartbeat in the quantum foam; [...] https://journals.aps.org/prresearch/abstract/10.1103/PhysRev...

Re:Listen to HD radio with a $30 RTL SDR dongle by KennyBlanken on Monday November 06, 2023 @03:01AM (#38159920)
There's also this thing called "a smartphone"
Re:Listen to HD radio with a $30 RTL SDR dongle by mplewis on Monday November 06, 2023 @04:22AM (#38160378)
Which smartphone do you have that can receive digital FM radio?
Re:Listen to HD radio with a $30 RTL SDR dongle by a6 on Monday November 06, 2023 @07:52AM (#38161899)
My Xiaomi Mi 10T has a built in app for receiving FM radio, and I'm sure my old Samsung galaxy also had it.
Re:Listen to HD radio with a $30 RTL SDR dongle by midnitewarrior on Monday November 06, 2023 @08:40AM (#38162430)
I think those had analog FM receivers. HD radio is digital FM, you need a special tuner for it.
Re:Listen to HD radio with a $30 RTL SDR dongle by a6 on Monday November 06, 2023 @11:17AM (#38164556)
I think in that case it looks like some LG phones had DAB/DAB+ tuners built-in.
Re:Listen to HD radio with a $30 RTL SDR dongle by Fnoord on Monday November 06, 2023 @10:53AM (#38164211)
My old Nokia N900 had a FM _transmitter_ allowing me to broadcast to my car.