> One can not use an "it was off value, so it MUST have been a VHF
> parasitic" as proof of the cause of damage. Many things, including
> temperature and time, cause carbon resistors to go off value.
I have an old SB-200 on the bench now that has the original factory
supplied tubes. This amp has been in constant use all these years.
Out of curiosity, I measured the two 47 ohm Rsupp stock Heath
suppressor resistors. They both had changed value identically to
59 ohms. No signs of heating; the color bands are bright as new.
Talking to the owner, this amp has never had any glitches of any
kind. One of the filter caps in the HVPS has just quietly "passed away"
and lowered the HV from 2400 to 1650.
I strongly suggest all owners of suppressors with carbon resistors
replace them with more modern units during the next annual "cleaning
and oiling." A very cheap and easy PM project.
(((73)))
Phil, K5PC
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