[Milsurplus] BC-9: Earlier and Later Operating Instructions.

[WA5CAB at cs.com]

Up until shortly before WW-II, components in equipment procurred by the 
Signal Corps had "Nomenclature", just like the assemblies of parts did. 
Thereafter, everything had a Signal Corps Stock Number but with a few notable 
exceptions such as tubes and wire and cable, parts had Part (officially Stock) 
Numbers and assemblies of parts had Nomenclature as well as Stock Numbers. The 
older system did make schematics confusing to people only used to the later 
system. Especially when there was a mix of old and new.

In a message dated 02/13/2017 02:17:09 AM Central Standard Time, 
kk5f at earthlink.net writes: 
> Ken wrote:
> 
> >From the similarity of the circuit AFTER the oscillator tube,
> >I suspect that the two transformers, T-2 and T-3 are simply
> >common 3:1 transformers.
> 
> Ken, there is no T3 in the BC-9-A. There are two T-1 and one T-2 AF 
> transformers. In the BC-9-* schematic, all identical components got the same 
> designation...hence two T-1s, two R-2s, and two R-3s.
> 
> T-1: Signal Corps Coil C-21, 1:4 (plate:grid) turns ratio.
> T-2: Signal Corps Coil C-57, 1:1 (plate:hi-z headphone) turns ratio.
> 
> Mike / KK5F
> 


Robert & Susan Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480
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