Rich,
Mostly shorts because of carbon traces along the ceramic on the outside of
the tube.
The removal of heat in this amp is marginal at best and the chimneys used
love to get bridle and sometimes burn leaving residue that will result in
carbon traces.
The best update to this amp besides changing the input to a tuned circuit is
to close the front opening of the tube deck, drill openings into it for air
passage ( or replace it with a new box) and the most important part....
install a external real blower who blows into the new box. Of course this
also means to use large chimneys but this should not be a problem.
Jamie
.
----- Original Message -----
From: measures <measures@vcnet.com>
To: 'AMPS' <amps@contesting.com>
Sent: Wednesday, October 13, 1999 5:50 PM
Subject: Re: [AMPS] amplifier problems
>
> >
> >A lot of time the step start resistor in this units blow because a too
large
> >fuse was in place; it should be a 1 1/4 amp slow blow ceramic fuse.
> >It will also blow if the relay contacts are bad ( open frame crummy
little
> >things -- bad design to use it in the first place had to change a lot of
> >them during my time working for ETO ( when Alpha Power was still ETO ).
It
> >also fails with a too large fuse AND the crow bar down with open case (HV
> >short) and also of course one of the 8874 shorted
>
> Was this an anode short or a grid/cathode short?
>
> > ( have seen a few of them
> >:-) ). A 20W resistor will work fine in this application I installed a
few
> >of those.
> >
> Thanks for the information, Jamie
>
>
> - Rich..., 805.386.3734, www.vcnet.com/measures.
>
>
> --
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