Thanks so much Bob... The choices are rough - $500 plus shipping for a new
transformer
from Tentec or $385 plus shipping both ways for a rewind job!
Yes, we get lightning, but this occurred when there was no lightning...
Any thoughts or ideas are appreciated. I may have to go with an external power
supply...
Brian AF4K
On 30 Jan 2014 at 22:05, Bob McGraw - K4TAX wrote:
> 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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> >
> >
> > _______________________________________________
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> >
>
>
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