Why not use a pad inside of the amp at the input link or tap?
Looking at the tube specs Im not sure the 5894 screens are up to GG use.
Its pretty close to a pair of 6146's in that respect. In AB grid driven
it is a very linear tube.
Link coupling will make it easy to tune out any reactance from carbon
comp resistors. I do this with a partially HB 6M transverter with a 6360
driving a 4X150A which started out as a P&H 6-150 TX converter with a
5894.
That is the unit I use to test all my 6M conversions as it has more than
sufficient power to drive anything.....so far.
Carl
KM1H
----- Original Message -----
From: "Glen Zook" <gzook@yahoo.com>
To: <Amps@contesting.com>
Sent: Wednesday, February 11, 2009 1:44 PM
Subject: [Amps] Dual tetrode in grounded grid
> Although not a "high powered" amplifier I am thinking of trying to use
> a 5894 (dual tetrode that is the next step up from the 829B) in
> grounded grid rather than the "normal" grid driven configuration on
> the 222 MHz band. The peak output would be around 100 watts.
>
> One of the reasons is because I have between 5 and 10 watts out of my
> transmitting converter and that is way too much for driving the grids
> of the 5894 in a grid driven linear application. Due to the design of
> the transmitting converter (also home brew with a 6360 dual tetrode
> final amplifier) I would have to use an attenuation pad between the
> converter and the linear instead of just dropping the power from the
> converter by detuning, etc.
>
> I started to build the amplifier in the usual push-pull configuration
> and then got to thinking about grounded grid. Anyone have any
> experience with running a dual tetrode with push-pull output in a
> grounded grid configuration? The 5894 has a single cathode connection
> for both tetrodes. Also, since it does have a separate cathode I
> don't have to think about a filament choke.
>
> Glen, K9STH
>
> Website: http://k9sth.com
>
>
>
>
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>
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