[GJim]

Good lord!

It was once common knowledge that VHF radio ("FM") typically doesn't travel over the horizon, LW and MW radio ("AM") travel by ground wave and are regional, but that you need shortwave kit for international and global communications.

Quite how a reader on a modern technical news site is unaware of this (no, you can't send direct messages to spies half way around the planet to be received on an "AM/M" car radio) shows just how common public knowledge of radio communications has faded over the last few years.