[Amps] AB2

John T. M. Lyles jtml@lanl.gov
Tue, 14 Jan 2003 08:44:19 -0700

I am designing with a 500 kW tetrode-based (Thales TH781 tube)  AB2 
amplifier at 200 MHz right now, running the loadline/fourier 
analysis. If i ran AB1 the thing would not produce what I want. But i 
am not looking for superb IMD for SSB, but only linearity to support 
'linear' power control in a closed loop over say a 20-35% range of 


>Rich said:
>>AB2 grid-driven makes rotten splatter with 4-400s.
>Not necesarily. But you do need a well regulated screen supply, a 'stiff'
>bias supply that doesn't move with grid current (mine moves under
>50millivolts), some RF NFB in the filament circuit, and about 3600volts on
>the plates.
>Pappenfus explains why AB2 can be more linear than AB1.
>Peter G3RZP