[TenTec] Centurion and AM

[Kim Elmore]

I didn't mean to imply that it should be tuned at a lower power level. I meant that it should be tuned to its max rated output (most will make more than this but may not be linear when they do) then switch to AM, send a carrier and observe the output. If it's more than 25% of the max output, reduce drive (only! Don't touch anything else!) to 25% of max output. Sorry if that wasn't clear. 

Kim N5OP

"People that make music together cannot be enemies, at least as long as the music lasts." -- Paul Hindemith

> On Aug 1, 2014, at 20:06, "Bob McGraw - K4TAX" <RMcGraw at Blomand.net> wrote:
> 
> Most 100 watt PEP transceivers will reduce power to 25 watts of carrier for the AM mode.  Amps like the Centurion have about 10 dB to 11 dB of gain thus 25 watts of drive will produce about 250 watts of carrier.
> 
> I never advocate tuning a linear amp at anything but for maximum output with recommended drive.   Just keep the grid current and plate current at or below maximum rated values.   Then if one wishes to reduce power or operate at a lesser level, reduce the drive and the amp will always be linear. Tuning at a lower power level will not assure linear operation and it can shorten tube life.
> 
> 73
> Bob, K4TAX
> 
> 
> ----- Original Message ----- From: "Kim Elmore" <cw_de_n5op at sbcglobal.net>
> To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
> Sent: Friday, August 01, 2014 7:34 PM
> Subject: Re: [TenTec] Centurion and AM
> 
> 
>> How about this: Tune the amp for its maximum clean PEP output at whatever drive level is needed. Switch to AM and adjust the carrier level to 1/4 of that output. Then operate happily.
>> 
>> Kim N5OP
>> 
>> 
>>> On 8/1/2014 7:28 PM, george fritkin via TenTec wrote:
>>> 200 to 250 watts AM results in 800 to 1000 watts PEP at 100% modulation. Three 811 tubes can not handle that power.  However if you are using low level AM from your xcvr you probably won't get 100% modulation so it might not be a problem.  If it were me, I would drop the power to 150 watts to be safe
>>>  Just my opinion
>>>  George, W6GF
>>> 
>>> 
>>> On Friday, August 1, 2014 4:57 PM, Robert <rmcgraw at blomand.net> wrote:
>>> 
>>> 
>>> Yes. Run about 200 to 250 watts of carrier BUT tune it for max output with 100 watts of drive.   Then switch to AM mode and adjust drive as necessary. Do not change amp tuning after switching to AM mode.
>>> 
>>> 
>>> 
>>> 73
>>> BOB, K4TAX
>>> 
>>> 
>>> Sent from my iPhone
>>> 
>>>> On Aug 1, 2014, at 5:40 PM, Timothy Johnston <timothy.f.johnston at gmail.com> wrote:
>>>> 
>>>> Can the Centurion (422b) be used with AM mode? The manual does not mention
>>>> it.
>>>> 
>>>> 73 de Tj, K4TFJ ...
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>> 
>> -- 
>> 
>> Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP SEL/MEL/Glider, N5OP, 2nd Class Radiotelegraph, GROL)
>> 
>> /"In theory there is no difference between theory and practice. But, in practice, there is." //-- Attributed to many people; it's so true that it doesn't matter who said it./
>> 
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