[Amps] Dual tetrode in grounded grid

[Glen Zook]

Using an attenuator pad at the input is what I was considering.  Of course I would rather use the power from the transmitting converter for something other than generating heat.  Basically I was seeing if using the 5894 in grounded grid rather than grid driven was possible.  I already have a pad on the input of the transmitting converter (to drop the output of my FT690RII from 8 watts to 2 watts) that I am using as the i.f. for the 222 MHz transmitting converter.  I like to use 50 MHz instead of 28 MHz as the input for my higher frequency units if possible although I am using 28 MHz for my 432 MHz SSB.

I normally do use link coupling above 50 MHz including in the 222 MHz transmitting converter which ends up with a 6360 mixer into a 6360 final amplifier.  I am presently getting a solid 5 watts out of the 6360 and if I tune it carefully I can get a little bit more.

Glen, K9STH

Website:  http://k9sth.com


--- On Wed, 2/11/09, Carl <km1h at jeremy.mv.com> wrote:

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.