[jker]

During pandemic I set up a little automated FM radio station for my block and the surrounding ones. It had a voice-synthesized DJ and a big randomized playlist of great music. The whole thing ran on an RPi with a little USB FM transmitter. My neighbors - the ones who still owned radios - loved it.

[nonethewiser]

Just to clarify, was this illegal?

[jker]

I don’t think so, the transmitter was under the power limit for amateur FM, and it didn’t overlap any local stations. That was my interpretation of the law as I read it before I built the station, doesn’t make it accurate or authoritative though.

[RF_Enthusiast]

A legal unlicensed FM transmitter could possibly cover a small area as described.

If it's line-of-sight on a frequency with no interference and stays at the legal limit of 250 microvolts per meter measured at 3 meters, and there's a good receiver with a good antenna, it's possible.