Suppressor grid g3 action measurements
I have posted several plate current sweeps to illustrate the effect of Suppressor grid g3 on plate current.
The plots can be found at
This last tube type was designed for strong control action by the suppressor grid g3.
The effect of g3 for the other tubes is fairly week for negative voltages down to -40V, while positive voltages at +40V and +150V were found to add a tetrode characteristic to the plate current.
A subtle but significant effect was found with the application of +7.4V to g3 of the DF97. Voltage gain increased by 3x, with an increase of 3x in plate resistance. See:
The effect of the suppressor grid was also addressed at these threads:
The Suppressor grid G3 characteristics for the EF50 have been posted.
A overview of the operation of dual control pentodes has been posted.