Very severe interference on the AM band.

[dtvmcdonald]

I have a minor problem with FM at my house. There are carriers every 31 kHz across the FM band, worst between 96 and 104 MHz. They appear at some other frequency
ranges from 27MHz to 300 MHz, and not at all at some other places.
They drift about at harmonics of 31+-0.5 kHz.

Luckily its FM and they are weak enough to be audible only if within 3 kHz of the main carrier or 38kHz, as they are 30 dB below the 19 kHz signal. They are not from
my apartment.