RadioBanter - View Single Post - AR88D

timlad28 · September 19th 10, 03:10 PM

Quote:

Originally Posted by Richard Knoppow

"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.
--
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

Hello Richard,

Thank you for answering my post. Today, I managed to check the tube voltages and V12, Anode 3, measures -1.2v, when it should be 30v. All other voltages check out.

- Tim