[Milsurplus] Pre-WW2 USAAF nomenclature

[WA5CAB at cs.com]

In a message dated 11/19/2005 6:41:03 PM Central Standard Time, 
kargo_cult at msn.com writes: 
> Okay, so far we know, for AIRCRAFT at least:
> 
> SCR-AB-XYZ
> 
> X relates to input voltage, of course. 
> 1= 12-14  volt
> 2= 24-28 volt
> 

Sorry, but looking at the rest of the SCR-1nn and SCR-2nn sets that I have 
firm information on, and specifically at SCR-18n and SCR-28n, it would appear 
that SCR-183/283 and SCR-187/287 are the only examples of this "rule".  Sets not 
following the rule that I can see are SCR-188, SCR-189, SCR-280, SCR-281, 
SCR-284 and SCR-288.  So it's much more likely that with the SCR-183 and SCR-187, 
which were assigned around the same time (the radio sets have different 
functions), the assignor merely took advantage of the fact that 283 and 287 had not 
yet been assigned.

> For two different equipment set-numbers YZ, the
> two sets can use some of same exact BC components,
> but have a different set purpose. For example,
> communications for one, and radiocompass for the other.
> 
> Since the unique Y,Z letters place the equipment in the
> series and the purpose is contained in the definition 
> next to the X, Y, Z in the list, letter A probably won't
> be the purpose or type designator.
> 

In position XYZ are numerals, not letters.  So I'm not sure what you meant 
here.  Are you confusing this with the AN/ system?

> I also note that SCR letter B does not need to use the 
> same B letter in the BC nomenclature. To explain,
> SCR-AB-186 uses receiver SCR-AE-179. Neat system,
> yes?
> 

All that that means is that the components and the overall system did not rev 
up every time one piece did (and the receiver would, in your example, be 
BC-AE-179).  But this is true of all of the nomenclature systems used then and 
since.  

> So - was this already speculated here? can letter A 
> represent the manufacturer? I have pawed thru 
> schematics and system drawings in the back of my
> manuals but nowhere is there seen, the name of the
> manuafacturer of the overall set.

Yes, I mentioned and dismissed it this afternoon.  What I said was that even 
in the mid thirties, the Signal Corps had far more than 26 contractors 
supplying systems and system components.  Remember that the Signal Corps nomenclature 
system covered every piece of equipment that they were responsible for, not 
just aircraft radios.

> -Hue

Robert Downs - Houston
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