[Milsurplus] More Navy radio in China 1944 - 1945

[W7QHO at aol.com]

In a message dated 6/19/05 9:30:09 PM, WA5CAB at cs.com writes:


> Nope.  The TBW output on A2 was the same as on A3.  And MCW is less 
> effective
> through QRM or QRN than A1.
> 

Actually, the TBW is rated for equal output on A1 and A2.   In the MCW (A2) 
mode, an 800 cycle modulating voltage is applied to the 803 PA tube suppressor 
grid, but the grid is NOT negatively biased to provide for linear operation as 
done in the A3 mode.   Also, in both A1 and A3 keying is done through the 
primaries of the transformers providing the PA B+ and the 800 cps drive to 
suppressor grid.   Don't know what the A2 output wave form looks like but must be 
rough.

Agree, though, that A2 would still be less effective than A1.

Dennis D. q     
Glendale, CA