[TenTec] 422 Centurion blowing fuses...

[David Propper]

Hi Bry,

Just thought that I would throw my 2 cents in as well. I purchased a used Centurion back in 2005, ran it for several years and then had the HV xfmr fail. Failure mode was an open secondary.  I chose to purchase a new one from TenTec which has run well for several years until I took the amp off line for other reasons.  There is truth to the history that TenTec has a reliability problem (i.e. failure at 15-16 years of age) with the earlier/older model Centurion HV xfmrs.

fyi and 73,
Dave, K2DP


On Jan 31, 2014, at 1:08 PM, Bry Carling <bcarling at cfl.rr.com> wrote:

> 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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> 
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