Often when those glass tubes set for a while they collect gas,
Usually people will turn the amp on for a day or so after storage without
High Voltage to let the filiments draw the gas out of the tube,
If you apply HV too soon, the gas could ionize and blow a hole in the grid.
Usually with a nice sounding pop....
If you see the purplish color at the top of the tube when you key the TX,
you got some gas in the tube.
This is the most prevelent cause of Tube death for tube amps.
Check the tubes....
Best wishes,
Rich
K5SF
>From: Ken Brown <ken.d.brown@verizon.net>
>Reply-To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
>To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
>Subject: Re: [TenTec] Centurion
>Date: Fri, 09 Dec 2005 21:32:42 -1000
>
>Hi Henry,
>
> >Centurion Gurus -
> >
>No, I'm not, but I'll venture to guess anyway.
>
> >I heard
> >a small pop -
> >
> >Resting plate current at first division - about 70 ma.
> >Plate voltage only 2000 volts and transformer hum sounds like the supply
>is
> >loaded heavily but showing only the 70 ma on the plate meter.
> >
>I wonder if a fault in the HV power supply rectifier or filter is
>loading the transformer, making the HV supply low as well as other
>control system and bias supplies that come from other secondaries on
>that transformer? Maybe that pop was a diode in the HV recifier going
>bad, although I understand they usually make loud pops when they do that.
>
>I would not recommend leaving it turned on for very long while it is
>making the hum like heavily loaded.
>
>DE N6KB
>
>
>
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