The answer to your question is gain. While the G-G configuration is the easiest
to implement, for a given input, the output is considerably less than if it
were grid driven.
My transceiver has 100w output and I can expect perhaps 1,300w with this drive.
However, the tube is capable of gobs of power with more drive. To achieve
higher power, either I will need a brick to drive it in G-G or operate it grid
driven. Yes, there are problems with this approach, but it is worth a look.
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