[TenTec] 422 Centurion blowing fuses...

[Bry Carling]

Thanks - I really appreciate the sage advice from you guys... it's a pity that the primary fuses 
and inrush circuit didn't properly protect the transformer, but to be fair it is an old one. Serial 
number is 11A10162. I wonder what year that signifies... I did notice that the core looks a bit 
stained or maybe rusty?

This amp only lasted for a few weeks after buying it used.  You can be sure I will add a fuse 
in the secondary after I repair it, and take a few other steps to better protect it. It seems 
obvious that these transformers from TenTec are being run to their absolute limit in the 
Centurion and should probably be derated a minimum of 10% in the future at this station. I 
will not be running at more than about 800-900 watts output after this bad experience. I think 
I will go the rewind route since the guys rewinding them has a great reputation, and will 
probably create something better insulated and more reliable than the original.

I probably shouild have spent more and bought a new amp to begin with, but it's difficult to 
spend the tens of thousands on ham gear that some guys are able to do...

Again many thanks to each person who shared comments and ideas.

Brian AF4K

On 31 Jan 2014 at 11:39, mcelmer1 wrote:

> I would keep it factory - the guys with the slide rules, pocket pens
> and 
> letters after their names usually are qualified to design and/or the
> transformer.
> 
> Mike
> W8TRN
> ----- Original Message ----- 
> From: "Mike Bryce" <prosolar at sssnet.com>
> To: "Brian Carling AF4K" <bcarling at cfl.rr.com>; "Discussion of
> Ten-Tec 
> Equipment" <tentec at contesting.com>
> Sent: Friday, January 31, 2014 09:45
> Subject: Re: [TenTec] 422 Centurion blowing fuses...
> 
> 
> Brian, Bob, and the group,
> 
> Let me pop in here with a bit of wisdom and a question
> 
> was the $385 rewind from ten-tec or from another company?
> 
> If if remember correctly, ten tec had some issues with their
> transformers 
> used in some of the amps.
> 
> If you have it rewound by a third party, you might end up with a
> better unit 
> than a new one from the factory.
> 
> Personally, an external high voltage power source always scares the
> snot out 
> of me. It´d keep it factory and used either rebuilt or new.
> 
> Mike Bryce wb8vge
> prosolar at sssnet.com
> 
> 
> 
> On Jan 31, 2014, at 7:39 AM, Bry Carling <bcarling at cfl.rr.com>
> wrote:
> 
> > 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
> >>
> 
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