I agree the R390A is quite a receiver. I used one regularlrly from
Panama, Canal Zone during the mid 60s. I was in the Signal Corps and
R390s were standard equiptmen in their Mobile Communications Vans.
Evenings I was able to pickup US BCB stations including at the time
WABC 770 in my
hometown of NYC

We only used a 30 ft. wire strung up in a clearing in the jungle,,Was
really nice hearing hometown news and current music as the local
Panamanian station had older music and very censred news.

Charlie
Essex, Maryland