[TenTec] 1999 Centurion amplifier - grid goes negative/output goes to zero

[Mike Schatzberg]

You can remove one tube, greatly reduce drive, and see if there is any output. Make sure the anode cap from the removed tube is clear of everything near it and not shorted. Replace all safety screening. 

You can test both tubes, one at a time. 

73,

Mike
W2AJI 

Sent from my iPhone

> On Mar 9, 2018, at 12:48 PM, Stan Gammons <s_gammons at charter.net> wrote:
> 
> Sounds like one of tubes shorted. If they are still under warranty, I'd contact RF Parts and see what they say.  They replaced a tube I had that shorted.
> 
> 
> 73
> 
> Stan
> KM4HQE
> 
> 
>> On March 9, 2018 11:11:45 AM CST, Bob  <w3hkk at roadrunner.com> wrote:
>> Bought this  used  from an estate sale in 2014.  Worked great for 3
>> yrs. Then a tube short blew a fuse.  Replaced both finals  and all was
>> well until a few months ago. The  amp  worked well for a few
>> transmissions, then the output went to zero.  After a few  cycles of
>> this I noticed the grid current which rested at zero began to migrate
>> negative.  As it   got worse, the output dropped to nil.
>> 
>> One suggestion was that one of my new tubes  ( from RF parts)   is
>> failing.  Another was  a possible problem in the AGC circuit.  
>> 
>> Other suggestions?  Also, I may need  a repair tech and don’t want to
>> ship the amp, so someone in Ohio or driving distance from central OH
>> would  be a plus.
>> 
>> Thanks.
>> 
>> Sent from Mail for Windows 10
>> 
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