I discovered mysterious hidden signals on a public radio channel (2013) [video]

This was a such a refreshing talk. She was monitoring the FM channel using a spectrum analyser (as one does, of course, haha) and got curious about this strange signal showing up next to the FM radio Channel.<p>The talk is about her attempts to learn about the Radio RDS (Radio Data System) standard, using a sound card to decode signals, finding a bit of bus-related information in that stream is weakly encrypted and proceeding to chasing it down. Very entertaining.<p>I&#x27;m so glad such people exist. I wish I could be one of these fearless and supremely knowledgeable people!

I found on her website [1] that she released a RDS decoder tool [2] relatively recently (compared to the 2013 of the video at least). Looks like it works with a USB RTL-SDR [3] receiver or a pre-recorded file in a number of formats.<p>[1]: <a href="https:&#x2F;&#x2F;www.windytan.com" rel="nofollow">https:&#x2F;&#x2F;www.windytan.com</a><p>[2]: <a href="https:&#x2F;&#x2F;github.com&#x2F;windytan&#x2F;redsea">https:&#x2F;&#x2F;github.com&#x2F;windytan&#x2F;redsea</a><p>[3]: <a href="https:&#x2F;&#x2F;www.rtl-sdr.com&#x2F;about-rtl-sdr" rel="nofollow">https:&#x2F;&#x2F;www.rtl-sdr.com&#x2F;about-rtl-sdr</a>

Are there still apps and the underlying hardware in smartphones to receive and decode FM RDS? IIRC some phone chips had FM radio receivers, but there were limitations like needing a wired headphone plugged in so that the headphone cable could be used as an antenna. I know a USB SDR could do it, but it would be neat if this were still a latent capability in the phone.<p>Of course I did a search in the Play Store but it&#x27;s crowded with streaming radio apps and SDR apps.

One thing I often wonder about with RDS: How do they stop the traffic alert (“TA”) feature being abused by stations to grab listeners?

&quot;So I got to work&quot;...<p>I love that hacker mindset :)

Wow, was that 2013? I saw this talk irl, can&#x27;t believe it has been that long

I was picking up WCBS in NYC at 5.105 GHz, near the antenna at Empire State. Never could figure it out, their engineers didn’t know why either.

Not sure whether it’s part of her talk, but this demonstration of the RDS stream she uploaded on Soundcloud is pretty cool:<p><a href="https:&#x2F;&#x2F;soundcloud.com&#x2F;windytan-1&#x2F;rds-mixdown" rel="nofollow">https:&#x2F;&#x2F;soundcloud.com&#x2F;windytan-1&#x2F;rds-mixdown</a>

This was great, I love these rabbit holes people go down, and it&#x27;s great when they then share the results. Very fun watch.

This makes me wonder, how do you reliably and securely encode steganographic content for distribution within a noisy medium?

I love the CCC website and the fact they host their own videos for a lot of reasons, but for some folks here is the YouTube video link:<p><a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=CnnbFWTNxZI" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=CnnbFWTNxZI</a>

We need a tl;dr on this one!

The actual title of the page is &quot;My journey into FM-RDS&quot; which definitely gives a better summary than what the current HN title says.

(2013)

I’m curious how folks who have the know-how to dissect a phenomenon “miss the forest for the trees” when they stumble upon a “mysterious” signal.<p>Alternate data streams in FM like RDS, IBOC audio and FM time are not some new-fangled tech. This would&#x2F;should be the first place to go to if you saw a signal that’s not modulated to analog audio.<p>Of course, the whole mystery aspect is just a hook and helps move the story along.