Hello Bill:
The circuit will work only for tetrodes that have screens and control grids
that can dissipate a large amount of power (many watts). Thus, the 4-400
and 4-1000 will work fine in grounded grid.
None of the ceramic tubes will do this (Maybe a 4CX10000 will). They do it
with sweep tubes, simply because it used to be a cheap way to get a lot of
power.
If you had a truck load of 4CX800 tubes for free (I have heard there are
some Russians in that position), you might try it, but you would be better
off doing it right or selling the tubes to get a triode. Besides, the
Russians can get the triodes easily.
A second problem with the design is that there is no cathode input circuit.
This loses about 5 db in intermodulation distortion.
73, Colin K7FM
> [Original Message]
> From: Bill Smith <ko4nrbs@yahoo.com>
> To: <k7fm@teleport.com>
To: <amps@contesting.com>
> Date: 10/23/02 5:59:35 AM
> Subject: 4CX800A Grounded Grid
>
> Is a design like this realistic?
>
> http://ru3ga.qrz.ru/LAMP/6.htm
>
> 73,
> Bill Smith KO4NR
>
> =====
> Bill Smith KO4NR
>
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--- COLIN LAMB
- k7fm@teleport.com
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