On Sat, 29 Mar 1997 22:38:28 -0500 Steve Bookout <sbookout@mnsinc.com>
writes:
>Hi all.
>
>Thought it was time I 'tweeked' the gray matter of the minds on this
>reflector.
>
>I've built homebrew amps over the last 15 or so years, but they have
>all
>been GG amps. Some have worked better than others. My first attempt
>was more of an attenuator; KW in; 100 watts drive and 50 watts out!
>But, I have learned from past errors and look back and laugh.
>
>For years I have wanted to build a grid driven amp and now I have a
>bit
>of an excuse to do it.
>
>The situation is as follows:
>
>I have decided to build a class C amp for 15 meters using a pair of
>4-400's. I ONLY work CW and I have lots of tubes, sockets, chimneys,
>fil xfmrs, etc.
>I would like to end up with close to 1500 watts when I'm done.
Why on earth Class C if you are not planning on AM? The power output
difference between "C" and GG "B" is tenths of a dB; 1500W out in GG
service is readily obtainable for CW (it would have relatively poor IMD
for SSB).
Class C also brings up the neutralizing requirement, plus a likelihood of
key clicks on CW.
Just a few comments from an old Class C builder.
73...Carl KM1H
I have
>the parts to build a stiff 4 KV B+ supply, easily capable of .6 amps.
>This would give me an input of 2400 watts or so. Should be enough.
>Some where I have the Eimac bible, "The Care and feeding of Power grid
>tubes" and my constant current curves for this tube, neither one I can
>find since moving.
>Can any of you all out there give me any insight into this project in
>general? Have you been there, done that?
>Any ideas on the grid and screen voltages I will need? (I need to
>start
>checking on what I have or make a list for Dayton)
>Am I asking too much from a pair of 4-400's?
>Am I nuts?
>Any insights based upon facts or experiences or where to look for more
>info, would be greatly appreciated. The old handbooks seem to be a
>wealth of info, but are dated in some respects (vac tube regulated
>pwer
>supplies and such)
>This could end up being a nostalgic thread.
>
>Thanks 73 de STeve, NJ4F
>
>--
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>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
>
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