As a child, neither I nor any chief engineers I spoke with could figure out why I was hearing a 1550 on 1430 with a perfect stability.
That haunted me until many years later when I understood that the missing ingredient in the formula was the 1490 less than half a mile away.
It was at the same time that I also understood the reason that I had trouble hearing a 1580 was because of a marine operator on 2490, the IF frequency higher.
As for that 1490, I also heard it on 580, the IF frequency lower. I was using some pretty god-awful vacuum tube AA5's.
And yes, I did make the mistake of touching the chassis (plural) more than once.