"clive & kristi ingram" wrote in
message
m...
hi. i've got a hallicrafters sx-42 that has developed a
strange s meter
problem.the receiver works on all bands but the s meter
works normaly only
on the first 2 bands,broadcast band and band 2 (1.6 to 5
mc). when I switch to band 3 (5
to 15 mc) and bands 4, 5 and 6 i hear signals but the s
meter indicates zero. occasionally
there will be a very slight negative indication with the
needle moving below the zero. it
must be getting ok avc on the first 2 bands but not on the
others. does anyone have any
suggestions?
73 ci

I am not sure the S-meter measures AVC action directly.
On my Hallicrafters (and other) receivers it measures
cathode or plate current in some tube. These meters are
usually reversed, i.e., when off the pointer goes to the
right (high end) of the scale. The meter in the SX-42 is
switched and also acts as a tuning meter for FM. It also
appears to be switched for different bands but the
schematics are confusing and I have not traced out the meter
circuit.
Check the tube socket voltages and resistances for a
start. Also, it should be obvious if the AVC is working or
not regardless of the meter.
The SX-42 is notoriously difficult to work on so I wish
you success and a good supply of patients.



--
Richard Knoppow
Los Angeles
WB6KBL