It appears after reviewing my QSK board problem and the blown fuses in
my Centurion, that I mis-wrote what happened.
I indeed had the same symptoms you had: Blown fuses for no apparent
reason. In my case the QSK board was blown, but in talking to Ten-Tec
service yesterday, they said the sequence happened like this: There was
a high voltage short from one of the 3-500Z tube plates to the top of
the cabinet, causing the fuses to blow. Guess when I had replaced the
tubes, one of the plate straps was too close to the top of the case and
arced over. The blowing of the fuses created a surge, or a spike,
which blew out the QSK board. The QSK board is very sensitive to the
fuses being blown, for whatever reason.
You may find, that the QSK board is blown in addition to the transformer
being shorted. The symptom will be that the standby/operate switch does
not work as it should, and the transmit light will be constantly on. If
that is the case, then you can get the "kit" to rebuild the QSK board,
or send the board to Ten-Tec for them to re-build, or have them send you
a new QSK board (Cost = $97), and/or the "kit" to rebuild your old
board and have as a spare. That is what I did. The Kit consists of 2
IC's and 5 Transistors, and cost about $20, as I remember.
I know you are concerned about putting so much money into the amp., but,
in my view, it is both necessary, and worth it, especially since you
already will have the big bucks invested in the re-wound transformer.
Again, Bry, good luck !
73, Donald K6RV
Message: 14 Date: Tue, 4 Feb 2014 06:18:44 -0800 From: Bry Carling
<bcarling@cfl.rr.com>
To: Discussion of Ten-Tec Equipment <tentec@contesting.com> Cc:
"tentec@contesting.com" <tentec@contesting.com> Subject: Re: [TenTec]
Centurion Amp. Problem Message-ID:
<42FCECBC-F96D-40EC-ACBB-A21415410F44@cfl.rr.com> Content-Type:
text/plain; charset=us-ascii
Thank you so much. They never brought up that possibility during my
calls to Tentec while troubleshooting. However the previous owner did
mention to me that the QSK board had already been replaced. This amp is
trying my patience. It's not just the money but the time. If I end up
replacing the QSK board too then I will have enough into it to have
bought a nicer amplifier. It's disappointing to think a QSK board could
cause main fuses to blow. I will try to learn how to troubleshoot that
section while my transformer is away being rewound. Thank you so much
for the insight about the QSK circuit. Bry AF4K
Best regards - Bry Carling
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|