Hacker Read

jameshart | karma 19910 | avg karma 4.65 · 2020-12-07 14:22:42+00:00

Outputting a TV signal isn’t inherently a problem, surely? Every VCR and 1980s home computer has a circuit that does the same thing. Would only be an issue if you run it through an amp and antenna, rather than just running a wire to a TV, right?

ddingus | karma 6068 | avg karma 1.19 · 2020-12-07 14:30:51

Those sources are likely shielded and clean.

A transmitter like this will radiate harmonics, and that's the major concern. It is not just a TV signal.

All that said, this is nice work. Analog signals are a lot of fun.

NTSC going away makes me sad. I have abused it to great results many times over the years.

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jameshart | karma 19910 | avg karma 4.65 · 2020-12-07 17:35:53+00:00

But doesn’t that concern about unshielded dirty signals apply to basically any use of a GPIO pin on a dev board?

ddingus | karma 6068 | avg karma 1.19 · 2020-12-07 19:43:06+00:00

Yes and no. Depends on the frequencies, whether the pin is driving a load, and intended to radiate.