[Milsurplus] Pre-WW2 USAAF nomenclature ?

[William Donzelli]

> I understand that in this example, SCR-AQ-183, BC-AQ-430, the letter Q
> is the "production series" -or  is there a better way to describe this?
> Contract?  But what about the letter A before the Q, what does it mean?

The middle codes are explained quite well in one of the (just) pre-War
manuals for of all things, field radio generators. Basically, if the
Signal Corps farmed out design of a new system [1] , the system would
first get a "tentative" nomenclature as it was tested [2]. When completed,
the military would have the specifications set. A manufacturer could make
a set under contract, but it had to conform to those specs. How they did
it was up to them. The variations in the design are designated in the
middle codes. The guy in the field could basically ignore them, and the
sets would work to spec. Under the covers was a different story [3].

I do not think there is any coding to the middle codes - they are
basically arbitrary. They are also not specific to the USAAF, but the
Signal Corps in general. Even the Army's navy used them.

> Has anyone ever seen the BC-183 external CW oscillator for the 
> SCR-183 ?

Yes, have two. One hacked to bits. [4]

> Apparently this style of noting the successive productions was
> abandoned about the time of the BC-224, 1936, or we would
> have BC-AA-224 and not BC-224-A.

I would agree with this. I think the middle codes were in effect for just
a few years.

[1] Note the the "middle code" systems are generally (always?) ones that
do not have the familiar "Designed by the Signal Corps" tags, yet just
about every other 1930s Signal Corps system does.

[2] These are the "T" numbers, like SCR-602-T6. These are NOT training
systems, even though JETDS (the AN/ system) uses it as such.

[3] While the SCR-*-183 sets are all basically the same under the covers,
some of the field radio generators are all completely different and VERY
MUCH depend on the middle codes, as the prime movers could be made by
different makers. To complicate things, the tentative SCR-183s are
completely different under the covers, but they did not last.

[4] One of mine is given the VERY confusing name of
BC-RC-183. 

William Donzelli
aw288 at osfn.org