[ARC5] 13.5 to 20 Mhz ARC-5 on Ebay

[David Stinson]

Tom Norris wrote:
> OK, not an ARC-5, but a CBY-46083.  Had an email conversation a while  
> back on this particular radio, but didn't save it.  So do I smell a  RAT 
> here, ummm, so to speak?  Not seen one before now.  Anyone have  more 
> info?  Here's the auction info.
> 
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5824973340

The 14 volt RAT and 28 volt RAT-1 were the first production sets
which later came to be know colloquially as "ARC-5."
There were four "flavors" of RAT produced:

CBY-46083 13-20 MC 14 Volt (black nomen tag)
CBY-46084 20-27 MC 14 Volt (black nomen tag)
CBY-46108 13-20 MC 28 Volt (blue nomen tag)
CBY-46109 20-27 MC 28 Volt (blue nomen tag)

A total of fifty of each receiver model were produced
and less than ten of each is known to have survived,
making them genuinely "rare" by my lights.
Only two complete sets (both receivers, two receiver rack,
dynos and control box) are known to exist in private hands.
Dynamotors, control boxes, racks, mounts and accessory drawers
were all serial-numbered distinctly from the receiver to
which they were attached- so, while you will not find
an RAT receiver with a serial number over 50, you
can find dynamotors and accessory drawers numbered
up to 100.  (i.e. complete RAT set number "1"
would have two receivers numbered "1,"  rack, mount
and control box "1," but dynamotors and accessory
drawers marked "1" and "2."  Therefore, the
"correct" configuration for RAT 13-20 MC receiver
#5 would be receiver #5, dyno and drawer #9.
RAT dynos were painted unwrinkled gloss black.

The most likely explanation for this particular
design (we have no first-tier information on
the RAT's mission)
was to provide receivers for a Navy
"G-" series liaison transmitter that worked
up to 27 MC.  At the end of the 1930s, the Navy
was experimenting with using these freqs from
aircraft (later abandoned).
However, this theory does not explain
why they designed the receivers to start at
13 MC instead of 12, where the common Navy
transmitters topped-out.  We have an eye-witness
story of the units being used, pre-American
war involvement, aboard British aircraft
for surveillance of these freqs, the high-HF Brit
equipment of the time being too heavy and
insensitive for the mission.
This is just a first-hand "story" with no
evidence to back it up; of course, I wouldn't
expect to find any evidence of such a project.
Take it or leave it as you judge best.

The Navy was so happy with the RAT and RAT-1's design
that they ordered receivers built in this style
that would cover 190 KC all the way to 27 MC.
This resulted in the huge and, frankly, unwieldy RAV,
which consisted of two racks of four receivers
each to cover the range.  An estimated 46 complete
sets were built.  They are far and away more
"rare" than the RAT, as only *three* examples
of the receivers are known to exist in private hands.
I know of none of the accessories surviving.
We have another eye-witness story- again;
no documentation- that the RAV sets were used
in the Med and were all sent to "Davy Jones Locker"
at the end of the war, having long been replaced
with receivers like the BC-348 and RAX, which
were much easier to use in the liaison role.

About the same time the Navy was ordering the RAV
for liaison use (1940), it decided to order a new,
more powerful Command Set based on the RAT/RAV design
which was first designated GT/RBD,
but later re-designated ATA/ARA,
which morphed into SCR-274N and AN/ARC-5.

And that's how the whole mess got started ;-).

73 DE Dave AB5S