On Oct 2, 2006, at 3:50 PM, Bob Green wrote:
OK, I've got the grids of the 572's grounded through 33 ohm resisters in
parallel with 940pf of capacitance. No smoke!!! Plates are NOT glowing!! I'm
getting a reading of approx 80-90 ma of plate current as read on the meter.
This looks normal, as far as I can remember. Things are looking up!
I must be really dense, but I still don't know how to hook up the meter to
read grid current though. Can anyone help, PLEASE!
Bob -- Grid current eventually gets back to the negative HV. It flows through the 33-ohms, to gnd, and from gnd through the grid-I meter shunt-R to HV-neg.
Typical values for the shunt-R are c. 1.0-ohm with a small, few k-ohm calibration resistor in series with the meter to make it read accurately.
cheerz
73,
Bob Green W6BBL
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