"Bill Ogden" wrote in message
...
Really stupid question: When checking resistors while
restoring an older receiver, is it common to attempt to
check the resistor while it is in the circuit? That is,
make a guesstimate of the parallel resistance (working
from the schematic). Or, should I disconnect one end of
each resistor to check it?

(Am working on an S-85. Have replaced most capacitors. No
hum and the B+ voltages are OK, so the original power
supply capacitors seem OK. General sensitivity is still
low, so resistor checks seem to be next on the list. IF
and RF alignment are OK. The last owner had the local osc
above the signal on band 4, which was the only serious
problem. Tubes are OK, I think.)

Why an S-85? It was my first receiver, way back when (with
a Heathkit Q multiplier).

Bill - W2WO
It depends on the circuit. Often even if there is a
parallel resistance path you can tell if a resistor is very
far from its value without lifting it but an accurate
measurement usually does require lifting one end. Carbon
composistion resistors are not very stable so its common to
find very old ones which are way out of spec.


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Richard Knoppow
Los Angeles, CA, USA