Headphone rm-radio: on weak signal, if I put my hand
up near it, it pulls in MUCH better.

Long ago, I recall that a tiny "transistor radio"
(1958? Japanese) would REALLY pull-in (AM I think
it was) when I put it next to a radiator-pipe.

What's happening -- and how to make it happen without
having to hold my hand up near my ears?

Thanks,

David