It is very helpful to question what has been done in the past so we can learn
from it.
Making real measurements helps also. I did not see the details of your
experiment
but comparison with directly grounded grids and the original circuit in the
same amplifier
would be useful. I have not seen all the email exchanges on this subject and I
may have
missed the details.
I after my emails are downloaded to my office computer I can't view them with
my home
computer.
73
Bill wa4lav
________________________________________
From: Carl [km1h@jeremy.mv.com]
Sent: Sunday, August 02, 2009 10:38 AM
To: Fuqua, Bill L; Herzog; Ham-amps
Subject: Re: [Amps] grounding grids
Mine is to leave things alone after performing the PM and other improvements
I mentioned earlier.
I get a kick out of a small minority always thinking they are better than
the design engineers. Yet when it comes to providing more than talk the
silence is deafening.
I also mentioned earlier that my spectrum analyzer tests showed a small IMD
improvement with the grids as built. My testing covered 80 to 6M. This was
later confirmed by Jacks report from the Drake L-4 designer.
Carl
KM1H
----- Original Message -----
From: "Fuqua, Bill L" <wlfuqu00@uky.edu>
To: "Herzog" <herzog@frontiernet.net>; "Ham-amps" <amps@contesting.com>
Sent: Sunday, August 02, 2009 12:24 AM
Subject: Re: [Amps] grounding grids
> The question we should ask now what are our preferences in grounding
> grids.
> Mine is as direct to ground as possible with the least series impedance.
>
> 73
> Bill wa4lav
> PS Has the gentleman trying out the 4cx250Bs in grounded grid (control
> grid connected to cathode) gotten any results?
> I would like to know how it turned out.
>
> 73
> Bill wa4lav
>
> ________________________________________
> From: amps-bounces@contesting.com [amps-bounces@contesting.com] On Behalf
> Of Herzog [herzog@frontiernet.net]
> Sent: Saturday, August 01, 2009 6:44 PM
> To: Ham-amps
> Subject: [Amps] grounding grids
>
> RE: What makes you think that the impedance between the grid and
> common changes by a factor of 10:1 between 3.5 and 29.7 MHz?
> 73
> Gary K4FMX
> =============
> That is a red herring. Because the frequency ratio is about 10 to one
> is the answer.
> This begs the question as to whether the impedance is enough to care
> about, and cap or inductive, or a series resonance. Such wonderful
> considerations are why we can discuss this matter after over 50 years.
> Wil
> _______________________________________________
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> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
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