There were a few things done by those who didn't understand the tech or how such things could cause problems. That sort of thing can cause a signal to splatter across a lot more than the intended channel. Another significant problem was using unauthorized amplifiers. People would buy stuff that wasn't approved by the government, crank it up and generate harmonics. The 2nd harmonic of 27 MHz is 54 MHz, which is right at the bottom of TV channel 2. The 3rd harmonic, at 81 MHz, could interfere Ch 5.Or was it the 500:1 compression being used in the mic amp...
1972got my amateur ticket in 1973