[Milsurplus] tank radio skip?

[Mike Morrow]

Hue wrote:

>I'm not sure what exactly the US FM equipment power was,
>but they were certainly the most powerful of the tank equipment

I think one can say with little fear of contradiction that U.S. HF/VHF-FM
gear was the finest tactical communication equipment in WWII.  The
SCR-508/528 (BC-603/604, 20-28 mc) and SCR-608/628 (BC-683/684, 27-39 mc)
were rated at 30 watts output, usually to an unloaded 10 foot whip.  These
sets were really state of the art for their times.  It's a shame that about
the only people interested in them are military vehicle collectors.

I suspect that in the first year of deployment of these sets, some
surprising long range contacts were possible, especially with the 20-28 mc
sets.  Average solar activity for cycle 17 began downward in 1939, yet it
was still near its cycle peak, and minimum activity at end of cycle didn't
occur until early 1944.

Several Vietnam War UH-1 pilots have told me of times when they could
communicate on their AN/ARC-131 low band VHF-FM sets (30-76 mc) with US
stations all over the Pacific, yet not to their intended station in VN.
That agrees with effects from the peak of solar activity in cycle 20 from
1967 to 1971.

Likewise, cycle 22's peak activity was from 1989 to 1992.  The report of an
aircraft in 1991 communicating with a base thousands of miles away could
very easily be accurate, if the attempted communication had been on the low
band VHF-FM sets that are standard equipment on many military aircraft,
rather than the assumed UHF-AM aircraft frequencies.

Mike / KK5F