[TenTec] Model 411 amp (aka Centaur)

[k8mp at aol.com]

 Thanks Al. I think that's what is going on here.?I don't have a Hi-pot unit.?If I can't fix it easily (and cheaply), it's going back on the shelf...


-----Original Message-----
From: Al Gulseth <wb5jnc at centurytel.net>
To: tentec <tentec at contesting.com>
Cc: k8mp <k8mp at aol.com>
Sent: Tue, Jan 26, 2016 2:54 pm
Subject: Re: [TenTec] Model 411 amp (aka Centaur)

 
 
 
Joe, 
 
Just an ohms check may not be enough. You may be dealing with an intermittent  
breakdown under high voltage. A "hi-pot" (high potential) test with an  
insulation tester etc. would be the only way to know for sure. A winding  
layer to adjacent layer partial short in the HV side could also account for  
your symptoms, and might not be obvious because the winding resistance could  
show right at the low edge of the manufacturer's spec. (I went through that  
scenario years ago with a HV filter choke in a small AM BC transmitter.) 
 
73 es GL, Al 
 
On Tue January 26 2016 11:28:03 am Joe Papworth via TenTec wrote: 
>    Thanks Andy. Was it the HV secondary that shorted? 
> 
> 
>   I isolated the HV secondary from the HV board and it reads open to the 
> frame and chassis. (Reads about 45 ohms when connected to the board) 
> 
> 
>   Thanks, Joe, K8MP 
> 
> 
>  -----Original Message----- 
>  From: P C Andy Anderson <xtraham58 at hotmail.com> 
>  To: Discussion of Ten-Tec Equipment <tentec at contesting.com> 
>  Sent: Tue, Jan 26, 2016 11:52 am 
>  Subject: Re: [TenTec] Model 411 amp (aka Centaur) 
> 
> 
> 
> 
>  Joe, I had a similar problem with my Centurion AMP.  It eventually failed 
>  completely. The secondary of the power transformer shorted to the frame. I 
> had the Xformer rewound at TRS.  BTW this transformer problem is a known. 
> 
>  73' Andy, W3LI 
> 
>  ________________________________________ 
> 
> 
>  Tuesday noontime, Joe: 
> 
>  I have a Centaur..............keep it covered when not in use. 
> 
>  My Elmer told me to always keep it covered..................dust is the 
>  problem. 
> 
>  Even when covered, open it up every two-three years and do a internal 
>  cleaning. 
> 
>  N1MHC/alsirois 
>  ============= 
> 
> 
> 
>  Gents, 
> 
> 
>  Have any of you gone a few rounds with a Centaur amp? 
>  I have a one that blows fuses very intermittently. It vaporizes them both, 
>  simultaneously, so it's apparently a dead-short somewhere. This happens 
> even in stand-by. (i.e. No key-down) 
> 
> 
>  Before I tear into it, anyone have any ideas of common failures in these 
>  amps? 
> 
> 
>  Later, Joe, K8MP 
> 
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