[ARC5] AN/ARC-7 ... Plus AN/ARC-6

[Mike Morrow]

> As a possibility exists that the receiver portion of the set, if
> it is proved satisfactory, may be used separately as a ground receiver
> with Radio Set SCR-522, the receiver is built as a separate unit,
> containing its own power supply.

Jack wrote:

> I'm curious about this paragraph.  I wonder what is
> meant by "ground receiver with Radio Set SCR-522".
>
> Could this paragraph have really meant to say
> "guard receiver" instead?

I believe that's *exactly* what was meant...but it's hard to know for sure.

BTW, the cited section of the "Graphic Survey..." has brief details of the
AN/ARC-6 on pages marked SECRET.  It was to be a 33-frequency, 8-channel
"UHF" set operating voice only between 225 to 285 MHz, about 5 watts output.
The description contains:

"Radio Set AN/ARC-6 (PREP) is an Ultra High Frequency Command Set now under
 development, providing line-of-sight communication of voice only, by means
 of pulse-modulated waves between aircraft and between aircraft and ground
 stations.  The set consists of a combined U.H.F. Transmitter-Receiver with
 dynamotor mounted in a single standard shock absorbing ANB mounting, and a
 control box which enables push button selection of eight preset channels
 which may be any of 33 channels within its frequency range of 225-285
 megacycles. Switches for manual control of the set are located on the
 control box, which is mounted on Mounting FT-240-A. The equipment operates
 on an input voltage of 28 volt D.C. and has an average power output of 4 to
 6 watts into a 50 ohm resistance load. Side-tone feature is available.

"Anti-jamming feature of the set is highly developed. The equipment is a
 narrow band systems [sic] necessitating the use of relatively slow speeds
 of transmission. It utilizes a printer mechanism in conjunction with other
 apparatus. This equipment was designed, not to replace existing
 communication equipment in the aircraft, but merely to supplement the
 present equipment.

"There were no Army Supply Program requirements as of 30 November 1944."

That states some rather interesting characteristics:
   "pulse-modulated waves",
   "a narrow band systems necessitating the use of relatively slow speeds
    of transmission",
   "utilizes a printer mechanism in conjunction with other apparatus",
   "not to replace existing  communication equipment".

I wonder just what all that meant, back in 1944.

Anyway, it's clear what the first ten AN/ARC- systems were:

AN/ARC-1   VHF Command
AN/ARC-2   MF/HF Command
AN/ARC-3   VHF Command
AN/ARC-4   VHF Command
AN/ARC-5   MF/HF Command, VHF Command
AN/ARC-6   UHF (actually VHF) Command (Special)
AN/ARC-7   VHF Command (glider et al)
AN/ARC-8   MF/HF Liaison (AN/ART-13A, AN/ARR-11)
AN/ARC-9   MF/HF Command (Bendix RTA-1B)
AN/ARC-10  VHF Relay (modified SCR-522-A)

Mike / KK5F