When you were working at Defense Electronics I’ll bet you came across a few old articles and references to the pre-communication satellite days and how the military especially the navy handled this in a nuclear war scenario.
While EMP can be handled by hardening and charge dumping circuits there is still the whole problem with a totally disrupted natural ionospheric layers. Under those conditions, it is predicted that long range HF radio just wont work on most bands most of the time.
What started out as a way to listen to Soviet radio and radar transmissions was utilized by the US Navy for a short time as a assured way to get intercontinental communications as long as the moon is in the sky. Although it is usually expensive to get started with Earth-Moon-Earth (EME or commonly called “Moon Bounce”) communications, I have found a nice site that covers using a lower powered 2 meter (144 MHz) setup that most of us could afford.
Here is a site about a hobbyist who watches for EME-bounced TV stations in Australia with simple gear
While communications ranks far lower than food supply, location, a simple defensive battery, and sustainability it is nice to know that you could contact prepared family, or even just listen for
signals from elsewhere on the planet even if a solar, nuclear, or other event were to cut off HF and normal amateur radio or commercial satellite communications. Kol Tov – David in Israel