[Amps] alpha 78

[Mike Schatzberg]

Hello Amp Fans:

I agree, I would bring the amp up slowly, watching the rise in high voltage,
that it is increasing proportionately with increasing line voltage.

Keep you eyes and nose close to the amp, looking for any tell tale signs of
component failure.

But, I would disconnect the anode clips before doing that.  First check the
amp's power supply, which is your main concern with the aging, beyond the
triode condition.

After everything looks good with the high voltage supply at full voltage,
allow the filaments on the triodes to operate for a few hours, before
applying high voltage to the plates following reattaching the anode clips.

The filaments may re-getter the tubes in a few hours at full line voltage.
If you do not have a variac to bring up the voltage for the power supply
check, at least disconnect the anodes and give the tubes some time at full
filament voltage before reconnecting the anode clips.

Regards,

Mike Schatzberg
WB2AJI


----- Original Message ----- 
From: "Marc Wullaert (ON4MA)" <marc.wullaert3 at pandora.be>
To: <hcawthra at sbcglobal.net>; <Amps at contesting.com>
Sent: Saturday, July 02, 2005 10:37 AM
Subject: Re: [Amps] alpha 78


> I should first inspect inside.Remove dust anyway.Check parts.Than use a
> variac to bring it up.
> ok?
> on4ma
> ----- Original Message -----
> From: <hcawthra at sbcglobal.net>
> To: <Amps at contesting.com>
> Sent: Saturday, July 02, 2005 4:29 PM
> Subject: [Amps] alpha 78
>
>
> > Just received a Alpha 78 amp. The 78 has been sitting on a shelf for 10
> years. Is there anything I should do before turning it on ? Replace ps
caps?
> >  Howard KA6IOB
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