Mxsmanic wrote
When was A-N retired? I have trouble just finding information about it; I
guess nobody who uses computers is old enough to remember it.

Well...it was properly called "radio range" and my Navy Advanced Training
Instrument check ride in the S-2F Tracker included a radio-range
orientation followed by a radio-range approach to the Alice, TX (ALI)
airport. This was followed by a radio-range missed approach with one engine
feathered. Then a single-engine mdf (manual direction finding)
approach...yes, using the loop mode and manually rotating it to find the
null. This was all way back in 1959. Not only do I use computers, I built
my first one from a hand full of parts back in the MITS Altair days,
probably before you were born, 1975 as I recall.

Bob Moore