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Re: [Amps] Tuning amplifiers

To: Carl <km1h@jeremy.mv.com>, "ka4inm@tampabay.rr.com" <ka4inm@tampabay.rr.com>, amps <amps@contesting.com>
Subject: Re: [Amps] Tuning amplifiers
From: "Fuqua, Bill L" <wlfuqu00@uky.edu>
Date: Sat, 30 Jan 2010 16:16:19 -0500
List-post: <amps@contesting.com">mailto:amps@contesting.com>
I kind of like the tuning method used by the 30S1. Perhaps a variation of that 
would be useful.
That is, knowing the gain of the amplifier when properly tuned, measure the 
ratio of output power to input power. 
With proper drive ,even pulsed, you can fine tune to that ratio. 
  Does anyone make a power gain meter?
Some old designs in QST  looked at the ratio of input voltage to output voltage 
directly at the tube. This ratio would be correct when
the plate was properly matched to the load.  I recall one that actually varied 
the bias to maintain linearity on high peaks. That is sort of 
a quasi-daf amplifier.
   Speaking of projects I still have to get back to my 4-1000A amp and 30S1 and 
Desk KW.  But where does anyone find spare time
these days?

73
Bill wa4lav

________________________________________
From: amps-bounces@contesting.com [amps-bounces@contesting.com] On Behalf Of 
Carl [km1h@jeremy.mv.com]
Sent: Saturday, January 30, 2010 3:58 PM
To: ka4inm@tampabay.rr.com; amps
Subject: Re: [Amps] Tuning amplifiers

With GG triodes, tetrodes, or pentodes, the grid current is the most
sensitive tuning indicator.

For grid driven tetrodes or pentodes the screen is the most sensitive tuning
indicator as well as the most easily damaged by mistuning.

Carl
KM1H


----- Original Message -----
From: "Ron Youvan" <ka4inm@tampabay.rr.com>
To: "amps" <amps@contesting.com>
Sent: Saturday, January 30, 2010 2:59 PM
Subject: [Amps] Tuning amplifiers


> Anyone:
>
>   I am confused by some of the things I am reading here about tuning,
> but I have long heard triodes and tetrodes are tuned differently,
> I have never figured out why or what, could someone enlighten us and I
> assume pentodes are tuned like tetrodes, right?
> (I have been tuning tube amplifiers for over 40 years now, normally
> with a swept test signal, frequently with -20 dB of drive.)
> --
>    Ron  KA4INM - He who attacks the fundamentals of the American
> broadcasting industry
>                  attacks democracy itself.        -- William S. Paley,
> chairman of CBS
>
> _______________________________________________
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> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps

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