"timlad28" wrote in
message ...

Hi,

The R.F gain on my AR88D has to turned almost fully
clockwise to hear
any stations. I can pick up stations across the bands but
can only hear
them clearly when the R.F gain is full on. I thought the
pot (R46) may
have failed.
I detached the RF gain pot and tested, the pot measured
from 0K to 68K.
The two resistors to ground are both in tolerance.

All bath tub capacitors were replaced. I had to replace
dud capacitors
in the RF unit to get all bands working and the odd
resistors that had
gone high. Up until recently the set was working OK. Then
the issue with
low RF gain.

All tubes have been checked and OK. I'm endeavouring to
understand the
RCA wiring schematic ;-) Has anybody encountered this
issue before?

Many thanks,
Tim




--
timlad28

Have you checked the tube voltages, if not do that
first. I think there are also stage gain values in the
handbook. These will help in finding where the signal is
disappearing. Using a good scope as a signal tracer will
also help.
RCA draws schematics with the tube bases shown as they
are which often makes them difficult to decipher. Sometimes
re-drawing a part of the circuit helps.


--
Richard Knoppow
Los Angeles
WB6KBL