Ian Jackson wrote:


The 'loop' probably refers to what was originally used in some types of
LW and MW radios, ie a large-ish, multi-turn air-cored loop.



** This pic shows the sort of air cored loop antenna I was referring to - along with a ferrite stick core version.

http://www.pbpix.com/Radio/loop-antenna.jpg

Air core loops were common in portable and AC powered valve radios until ferrite versions took over sometime in the 1950s.

When pocket size transistor radios appeared, a compact ferrite rod antenna was the only usable type.


.... Phil