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
power.
73
John
>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.
>
>73
>
>Peter G3RZP
|