[AMPS] Re: resistance

[w0ex@scan.missouri.org (Richard Carroll)]

>
> > A 2W carbon resistor will show a gradual and steady R increase when run
> > above 1W or so....this is at DC.
> 
> Amen Carl. That's why carbon resistors should NEVER be used in power
> supplies across electrolytics.


  Years ago I worked on a GE High band VHF base station that had blown
the AC fuse in the plate supply. It was an old unit, in service about 15
years. The trouble turned out to be a 100K ohm 2 watt carbon resistor
across the electrolytic filter cap that had worked it's way *DOWN* in
value to 30 ohms.  Quite out of character. The rig couldn't have worked
long at all with the lowered resistance. It must have happened rather
suddenly.

Dick W0EX

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