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

[William Donzelli]

> 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.

Can this really be viewed as absolute? The General Electric RBD could very
well have been placed in aircraft service. It is fairly compact and light
and runs off DC from a dynamotor. The mating transmitter TCX (has anyone
ever captured one) probably was fairly light as well. I know the manual
(or directory, I forget which) says for use on small vessels, but that
never stopped the Navy. 

The "real" RBD, however, was (probably) not yet available at the time of 
the book's publication.

> Thus we see that the switch to the ARA/ATA nomenclatures
> had not been completed by August of 1940.  

I think one very important set of clues can be found in the original 
wording of the contracts. If you could find the writeups for
NOs-74912 (perhaps the first ARA/ATA contract) and NOs-87630 (probably 
the only RBD/TCX contract), you might get some answers.

The only problem is getting a hold of these contracts. NARA probably has 
them, but it also probably involved a trip to Maryland!

> This being the case, there should be GT/RBD nomenclatured 
> radios out there somewhere.

I still doubt it (for the RBDs, anyway). I would think that by the time 
the radios were ready for their tags in the ARC factory, the "real" RBDs 
fate was sealed in contract.

I can see GTs being out there. Certainly a number of sets slipped away 
from the great AN/ system renaming - it would be sensible to think 
that a few GTs may have made it.

> 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.

Possibly, but it was far more common for reworks to get suffices. 
Rebuilts of RE became RE-a. TBF became TBF-a. Sometimes major reworks 
changed the number, as in TBA-6s turned TBA-10s (FSK box added). The only 
instance I know of where the Navy retagged something with a completely 
new nomenclature is QBF to QJA - this makes a lot of sense, as the second 
letter of underwater sound equipments designates the basic technology 
used (mostly in the projector). Anyway, the sonar guys play by their own 
set of rules.

> It could have been as simple as installing a new nomenclature tag
> to turn an RBD (or an RAV) into an ARA.

Simple, yes, but possibly a logistic nightmare. It would have made a 
whole bunch more sense for the Navy to revise the contract with GE, 
saying basically "you are not designing RBDs anymore, you are designing 
RYZs, because we already have a bunch of RBDs". Occam's razor in action.

> I have a DM-32 dynamotor tag that was flipped over
> and restamped for the later D-10.

This could have been ARC surplus, too.
  
William Donzelli
aw288@osfn.org