I’m beautiful and tough like a diamond…or beef jerky in a ball gown.

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Joined 9 months ago
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Cake day: July 15th, 2025

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  • I was surprised by that, too. When I went looking for a way to decode them with RTL-SDR, I assumed it wouldn’t be parsing the audio but a narrowband data stream. TIL also.

    Edit: It does kind of make sense with it being AFSK encoded in-band, though, or maybe I’m just so used to it being that way. I always thought the screeches were there to demand attention (and also be something that headend equipment can pick up and respond to). So it’s interesting they’re doing double duty as both an unmistakable audio cue to pay attention as well as containing the actual alert data.

    Plus there are NOAA stations all over the country rather than centralized like the time signal transmitters. It was probably cheaper to do it in band at that scale.