Very Interesting!
My Viewstar had the same problem.
Ended out building new capacitor mounts as exact replacements not available
here.
Used new German hi spec resistors. No problems since.
73
end
Barry Kirkwood PhD ZL1DD
Signal Hill Homestay
66 Cory Road
Palm Beach
Waiheke Island 1240
NEW ZEALAND
www.waiheke.co.nz/signal.htm
----- Original Message -----
From: Tom Rauch <w8ji@akorn.net>
To: <amps@contesting.com>; Phil (VA3UX) <phil@vaxxine.com>
Cc: <K4SO@aol.com>
Sent: Thursday, 04 October, 2001 12:23 AM
Subject: Re: [AMPS] Noises in electrolytic capacitors
>
>
> > 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
>
> --
> FAQ on WWW: http://www.contesting.com/FAQ/amps
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
>
>
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|