[ARC5] ARC-5: More on the RBD Nomenclature

[David Stinson]

As we've discovered,
the radio set that became ATA/ARA was first nomenclatured GT/RBD.
The RBD identification was later reissued 
to a none-aircraft set similar to the RAX.

I've recently acquired a Navy Radio Materials School
text on direction finders.  The book is dated August of 1940.
In the chapter on aircraft direction finders, there is a section
dividing the aircraft RDF units into several groups, 
mainly by the type of aircraft in which they are mounted.
In several of these groups, we find the passage:

 "DFs in this group are used in conjunction with a 
  communications receiver Model RU, RBD or RAV."

Thus we see that the switch to the ARA/ATA nomenclatures
had not been completed by August of 1940.  
Also interesting to note the mention of the RAV.

This being the case, there should be GT/RBD nomenclatured 
radios out there somewhere.  And this leads me to another 
question:  Were RAV and RBD radios reworked and 
tagged "ARA?"  The practice of reworking older sets
to fit newer standards was certainly practiced at the time.
There are little or no electrical differences between
the RAV and the ARA; the A.R.C. drawing 
and part numbers are identical.
This may be the case for the earlier RBD.  
It could have been as simple as installing a new nomenclature tag
to turn an RBD (or an RAV) into an ARA.
If so, I would expect that only the 1st-run ARAs
(those with dated contract tags) would be candidates.

I have a DM-32 dynamotor tag that was flipped over
and restamped for the later D-10.  
It's possible that- were we able to look under that ATA/ARA tag, 
we might see a GT or an RBD.
I'm not going to pop mine off to look.
At least, not before finding some way to determine if
they've been flipped.

73 Dave S. AB5S