[ARC5] F13A

[Mike Hanz]

This is a fairly classic circuit for an aircraft interphone amplifier, 
and being ARC, that's my guess at what it is.  I'll do some digging in 
the docs later this weekend and see if I can come up with something more 
definitive for you.  Clearly post WWII commercial, though.

Best 73,
Mike

Brad Hernlem wrote:
> Here is some more info on this unit. Does anyone know what this was part 
> of or what it was used for? I would appreciate any help.
> 
> The front has a metal plate bearing the following:
> 
> AUDIO AMPLIFIER
> TYPE F-13 A
> SERIAL #566  2.5 LBS.
> Aircraft Radio Corporation
> BOONTON NEW JERSEY
>
> The circuit is very simple. A signal from J-102 pin E goes to the trim 
> pot. Its wiper goes to a transformer T101 that outputs to two resistor 
> voltage dividers to pins 1 of the two tubes. Their outputs drive the 
> output transformer T102 in push-pull. The output transformer has four 
> output connections (two midway taps).