[ARC5] A.R.C., "ARC-5", "ARC-12" and "ARC-type-12"

[David Stinson]

For general interest:
As with the label "ARC-5," which has become 
"shorthand" for the three different WWII-era 
HF Command Set systems produced by A.R.C. and 
others, it's become customary to refer to all the grey 
sets produced post-war by A.R.C. as "type-12."
Indeed; military manuals covering those sets designed 
for communications refer to them collectively 
as "type-12."

However, A.R.C. itself referred to different combinations
and applications of these sets by differing "type-" numbers.
Examples:
The "A.R.C. type 11" set, with R-11 "Range" receiver 
and T-11 VHF transmitter, which fit the near-universal
"tower on longwave, aircraft on high-band" civil aviation
system of the time.
The "A.R.C. type 17" VHF-only set, with R-15 
and T-11 transmitters.  I built this set.
The "A.R.C. type 15" is a navigation set.

GL ES 73 DE Dave AB5S