On Mar 13, 12:33*am, "Lynn" wrote:
* * *Anyone ever bother to check resistor values? During overhaul and repair
of lots of tube era marine electronics, many composition (and films
sometimes) resistors had changed value considerably. Especially those used
in voltage dropping circuits. High value resistors ( half megohm or more)
seemed to be pretty wild too.
* * *Of course checking frequently meant disconnecting from associated
circuitry to check is a real
pain in the you know what, but the end result, (including the condenser
replacements) resulted in amazing results!
* * *Anybody find similar resistor drift?

I do. My general rule is to replace or bridge resistors if they
deviate 15 percent or more from their marked value. However, if their
value isn't all that critical (e.g. a large value resistor in series
with a screen grid), I'll leave it alone. I prefer to replace rather
than bridge; however, if I don't have a suitable replacement I'll
bridge if the resistor has drifted up in value, which is often the
case.

Dave Drumheller, K3WQ