Snow.

[wa2ise]

Originally Posted by kbmuri

But you're describing the problem I left it at last, to a T. It picks up local UHF channel 15 for some reason, around channel 12 or 11 on the dial, with no antenna at all, watchably but snowy. Maybe it's a harmonic, or maybe my local oscillator's just that far out of whack.

That oscillator would have to be way off, as channel 11 is at around 206MHz, and channel 15 s at about 480MHz. But the oscillator's 2nd harmonic could find itself at 520 or so MHz, as well as 260Mhz, if your IF is at 40MHz.