Re: Pentode amp experiment.
It's not surprising the EL34 takes a lot of current with zero bias!
As a triode with 250V on the anode/g2 and -15.5V on the grid (g1) it is supposed to take 70mA. With zero bias it goes off the data curves somewhere in excess of 250mA! To wind it back even to 10mA would need nearly -30V on the grid or somewhere around a 3.3K cathode resistor (bypassed for RF by say 100nF).
As an RF amplifier, in triode form it may well be unstable, if it's got any useful gain. Using it as a pentode would seem a better bet.....
Chris
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