> Thinking back a number of years, I had exactly the same experience
> with the equalizers in my Viewstar amp. Two of them were open, with
> absolutely no visual evidence that anything was wrong.
While I have no idea specifically about the resistor used in that
case, when looking at the parts inherited from other "XXXXstar"
bankruptcy purchases many were surplus.
Amp supply had the same purchase mentality. I remember all the
HV 1 megohm meter multiplier resistors purchased from Electronic
Surplus in Cleveland, and how often they failed despite being
operated under their ratings. Obviously those resistors were there
because someone dumped them.
The problem with that is some parts are on the surplus market
because they are rejects, and unreliable. Surplus parts are never a
bargain, because you can usually buy the parts new and with
some assurance they are OK for less money.
Bleeder and equalizing resistors should be high-rel parts. They
should NEVER be carbon or carbon film, and they should be 100%
tested. Wire wound parts are actually just as reliable as film or
oxide resistors, if you get good parts.
Carbon resistors are a huge problem, and should never be used.
The same goes for resistors that rivet or crimp resistance wire to a
terminal.
73, Tom W8JI
W8JI@contesting.com
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