[R-390] Anyone know what a 2C254 Audio Amplifier Module is?

[Bill Smith]

Hi, ran across a plug-in module which looks similar in assembly to R-390
type modules.  The chassis is 3-3/8" x 7" x 2" deep and is apparently held
to a main chassis by two captured 10-32 screws, one at each long end of the
chassis.

The module is comprised of three tubes and three transformers (input,
interstage, output?) all of which are the same size.  The transformers are
all lined up along one side of the chassis, and the tubes are lined up along
the other side.  The two 6V6's are separated by an assembly of four 20mfd.
oil-filled capacitors which are under a gray cover.  The tubes are (1) 12SJ7
and (2) 6V6.

Underneath, a 12-pin Jones plug provides all input and output.  S201 is a
DPDT toggle switch (function?) and S202 is a 1-pole 6-position rotary switch
with a 3/8" black round knob with a white-painted screwdriver slot in the
end.  Both are accessible from a rectangular slot cut in the side of the
chassis.

Someone has penciled "2C254 Audio Amp" on the chassis.  Any ideas?
Schematic?


73 de Bill, AB6MT
billsmith@ispwest.com