Fairly certain it's a line filter.
Who knew that would lead to a career in computers.....
.......
The glow of the dial in a dark room, headphones on, these boys were discovering there was a far larger world out there than just their little town as Radio Netherlands, HCJB (Equador), the BBC and other big signals rained down on the bare wire strung through some trees.
Some of us couldn't afford a Halicrafters - or didn't know anyone who had one. Others like me just ordered a Heathkit short wave radio and built it ourselves. Who knew that would lead to a career in computers.....
Cheers,
David
Yep, that's exactly how I spent a large part of my childhood
I was 13 when my father purchased a used Heathkit GR-64....
still have that radio today, and it still works ! I also had a bunch
of QSL cards from those stations like BBC, HCJB, VOA, etc....