Bill Ogden wrote:
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?

If you check it in-circuit, it will read at or lower than the resistor
value. It could be _lower_ because there is other stuff in the circuit
in parallel with the resistor. It could be _the same_ because that stuff
may not have any DC resistance when the thing isn't powered up. It will
not ever be higher unless the resistor is bad.

Since most resistors fail into a higher than normal value, or open, rather
than into a short, measuring in-circuit gives you a good quick way to find
a large proportion of bad resistors. But it won't find all of them.

(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.)

Where did you check the B+ voltages? I would be apt to check plate and
cathode voltages at each tube and make sure they are roughly sane.

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

Well, why not an S-85?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."