Sorry to learn of the bad news.
There are companies around that can rewind/rebuild that transformer.
Certainly worth checking into as opposed to engineering some other
transformer in its place.
Per chance have you had a lightning strike lately? That will do it.
73
Bob, K4TAX
----- Original Message -----
From: "Bry Carling" <bcarling@cfl.rr.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Thursday, January 30, 2014 9:54 PM
Subject: Re: [TenTec] 422 Centurion blowing fuses...
Thanks Bob, but the power transformer is shot.
It spontaneously died for no apprent reason. Tubes are not shorted, and
the rectoifoers amd
cap are intact.
One of the two primary windings has shorted out completely. The other is
OK.
Anyone have a hypersil transformer they would like to sell?
Brian, AF4K
On 30 Jan 2014 at 17:21, Bob McGraw - K4TAX wrote:
When the power switch is ON there is the HV also applied. Thus I
wouldn't
expect shorted tubes or any HV component. Likely the bias diode
shorted
thus when switched to Operate the tubes fully conduct and take out
the fuse.
Watch for Plate current to peg.
With amp ON and the Operate switch in Standby, you should be able to
see the
HV on the meter. The Operate switch basically changes the control
mode,
thus the internal T/R switching is activated.
73
Bob, K4TAX
----- Original Message -----
From: "Bry Carling" <bcarling@cfl.rr.com>
To: <tentec@contesting.com>
Sent: Thursday, January 30, 2014 2:30 PM
Subject: [TenTec] 422 Centurion blowing fuses...
>I have a Tentec 422 Centurion that is blowing the main 20 Amp
fuses...
>
> Looking for insights to this amp failure. It started
spontaneously.
> I can turn on the main power OK and the filaments light up on
the
> 3-500Zs. The 12 volt power supply is OK because the pilot lights
come on.
> However when I flip the standby - operate switch to the Operate
positionm
> the fuse or fuses will blow. I replaced them with good 250V 20A
cuses.
>
> I checked the plate transformer windings and everything seems
normal for
> all three windings. Nothing is shorted. The safety ground for the
> cover-open condition is not
> across the HV plate supply. I checked that nothing else is
shorting out
> the plate supply
> either.
>
> Does anyone have any idea what might be going on here?
>
> Many thanks - Brian Carling, AF4K
>
>
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
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