[R-390] More "bad" resistor comments and questions (a bit long)

[Barry]

It occurred to me last night as I was about to go to bed about what you're
saying.  I was thinking I was effectively isolating the resistor, but that's
not true.

It also occurred to me that unless that 5000pf capacitor leaks quite a bit
more under operating voltage, the reading I'm getting across the parallel RC
circuit isn't enough out of tolerance to effect things all that much.  If I
were getting 1/4 or 1/10 the expected reading, then, yes, the cap would be
very suspect, but no more than I was seeing, it's probably nothing to worry
about and just some very low-reading resistors.

Barry - N4BUQ

> Hi Barry,
>
> > so I can't account for the
> > difference between the "then" and "now" readings.
>
> Simple. You have a bunch of two resistor voltage dividers feeding
> the screens of various 6BA6s. They are in parallel. If you measure
> a single 27K resistor "in circuit", the reading is affected
> (lowered) by the other parallel voltage dividers.
> That's why you clip one end of a resistor to verify its value.
>
> And your screen resistors are 27K, eh? I'll have to recheck
> carefully now that I'm back home, 'cuz I woulda sworn one
> IF deck had badly out of spec 22Ks.
>
> Regards,
> Gary
>