[ARC5] History and Context of the ARC-5 sets

[gordon white]

    Just a few points:
            
    The army was the prime driver of the A.R.C. "Command Sets" which 
included short-range radios designed for plane-to-plane communications 
as well as local area field-to-plane work. Arnold and others routinely 
flew up to Boonton, N.J. from Washington for scotch and poker with Drake 
and others at A.R.C. (Highly illegal today, but in thr 1930s it worked 
well.)

    There was long a lot of tension between the Air Corps and the Signal 
Corps, headquartered at Ft. Monmouth. The Air Corps' technical center 
was Wright Field, at Dayton. There was a major battle over a DF 
navigation set the Signal Corps wanted to foist on the Air Force, but 
that's another story.

    As the war neared, the Signal Corps wanted the Air Corps to use a 
crystal-controlled set, which was actually put out for bid and built, 
the SCR-240, if memory serves. The Air Corps rejected it on two grounds 
- it was "the size of a foot locker" and crystals were in short supply, 
in days before multiplier circuits could generate multiple frequencies 
from a few crystals. The Navy was also suspicious of crystals, after a 
fleet problem in the 1930s during which units could not communicate 
because of the wrong crystals being provided.

    In my opinion, it was largely Ft. Monmouth that kept the Army from 
buying the A.R.C/ Command Sets before the Navy.

    I doubt if there was any vhf at Midway - probably RU 
tuned-radio-frequency receivers and their accompanying GF transmitters. 
Probably a few ARA/ATA MF/HF "Command Sets" and maybe, in PBYs, RAV 
receivers.

    The first commonly-used vhf set was a British unit, nomenclatured by 
the U.S. as SCR- 522 and built here under license.

    Of course vhf is a much shorter-range system than MF-HF. Excellent 
for plane-to-plane and landing control.

    RE the air mail: The equipment that failed during the air mail 
disaster was the then-current TRF gear, and what was bought as an 
upgrade was just improved TRF receiver gear and "better" transmitters. I 
believe the air mail generated the design of Aircraft Radio Corp's Type 
K and the ARA/ATA, AN/ARC-5 equipment, (All of it quite similar) but it 
was not immediate. There were a lot of other reasons that Air Corps 
pilots, trained in good weather (hard to fight in bad weather, as we saw 
during the Battle of the Bulge) were not able to fly the air mail in 
miserable late-winter weather over the northeastern U.S. but radio 
inadequacies were part of that equation.

- Gordon White