Thread: Testing 807's.
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Old 12th Jul 2018, 5:27 pm   #4
Hartley118
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Location: Cambridge, Cambs. UK.
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Default Re: Testing 807's.

I find on my AVO VCM MK4 that some 807s give randomly high anode current readings. I've always assumed that the reason is RF instability, but have never gone so far as to put a scope on them (VCM and scope live in separate sheds!). Presumably some feature of the internal VCM wiring encourages occasional oscillation, though why particularly on 807s I don't know.

I find that the general fix is to plug the valve into an actual amplifier and measure it in circuit.

Martin
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