[Amps] Looking for shematic to set MRF448 into Class AB

[DH5HV]

Hello.

I got a commercial RF-generator for ENI.


It has 4 power modules with two ENI21 transistors per module.

The ENI21 for sure is a Motorola device and due to the fact that each module should bring up more than 300W with two of these ENI21 at a voltage of aprox. 50V up to max 30MHz I would say it should be the MRF448.

Am I correct ? Otherwise correct me !

Now my problem:
Looking into the shematic I see the MRFs in zero bias mode.
The base of each transistor is connected to ground and the modules just get the 50V. Nothing more.


I would like to cut the connection of the base to ground and spend some voltage there to get a current flowing through the MRFs.


I found also an application in the Motorola application book, but maybe someone has a nice design on his PC including shematic and maybe layout to make some prints ?!?

I just have the 50V with looooooots of amperes in the generator to build the bias voltage.....   ;-)
Maybe I can also place a very small second trafo inside, which should be the better solution maybe....



Jochen