I remember, as a kid in the 60s, playing with a neighbors large old floor model radio. It had several odd frequencies which were labeled HAM. You would hear very spooky things on it, esp the number readers. I was told that these were secret codes which were slowly read out loud. Also Morse code and some one reading ship's coordinates.

On a similar note, when I lived a year in Philly, there was a lot of talk about renegade radio stations, run by amateurs, from their house. They would set up an antenna and broadcast different things. One was for an Hispanic neighborhood. I don't hear about these in Baltimore.