At the moment I have 5x RTL-SDR dongles streaming into a box on different bands (137, 433, 912, 978, and 1090 MHz). They pick up all kinds of things, from local weather stations to the water meter for my condo to ADS-B/UAT transmissions from local aircraft. I even see the tire pressure monitor signals from cars that drive by (some of you guys need to add air!).

Mostly it's just fun. I like peeking at all the ambient transmissions in the area.

A while back I was more deeply involved in the SDR space and even reverse-engineered some pager signals. At least a few years ago, pagers were still widely used in hospitals (totally in plaintext, by the way).

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bartwr 2 hours ago | parent [-]

I am learning about radio and modulation using SDR (with professor Claude - incredible for learning! Especially if you know exactly what you want to learn and have a strong enough background in somewhat related fields - audio and image DSP for me - to make exercises it writes for me short, relatable, and yet illuminating) and our second lesson after cheap 433 remotes was FLEX and pagers - plenty of that stuff in the city, with about half messages from a hospital a few blocks away. Still very widely used in the US (I live in NYC). Seeing what gets broadcasted there 100% unencrypted was quite a shock. Patient names, ages, and conditions; doctor names, rooms, departments, requests for medications and assistance... Insane amount of super private PII.

	▲	goodmythical an hour ago \| parent [-]
		off-topic, but "with professor Claude - incredible for learning! Especially if you know exactly what you want to learn " This always strikes me in the "oh no look at all the cheating!" anti-ai takes. Like, the cheating only blew up because there was/is the gap in teacher/professor/moderator understanding of the tools. Kids were copying wikipedia back in the day, and if the kid had a decent vocab, went completely undetected for a time. Then everyone thought they could do it and scorers got suspiscious enough to create a demand for an "is this wikipedia" software such that companies made them and scorers implemented them. We even saw reversions to written exams, and have had continuous use of written exams in 'critical' tests like SAT et al. And of course, the only reason that the teacher's ensure that the students aren't cheating is because they know the students are heading for tests they can't cheat. So, there's new cheating, there will need to be new detection. A motivated learner today has unprecedented capabilites compared to a motivated learner of even 10 years ago. Assuming, of course, that the learner is practicing universally accepted study/research methods such as never implicitly trusting single sources, especially when they're third hand summaries of unverified sources. I've had proffesors give me incorrect information with every bit of certainty an LLM offers, but it wouldn't be their fault if I just nodded along with either of them.