"rijo1" wrote in message
...
No Ken , the tubes are used in a RF circuit . I can't take a amp reading
off the
circuit without loading the circuit with RF . That is the problem .
The voltage is too high and is driving the tubes too hard and turning the
plates
RED in a matter of seconds . The tubes cost $ 93.00 each and I don't want
to
kill them . There is no RF on the filaments but only on the plate caps .
Thanks

Can't you disconnect the plate current so you're just running the filaments,
then measure the current? You could always use trial and error, start with a
resistor you know is too many ohms and then tweak it until you get it right,
they even made wirewould adjustable resistors for tasks like this, not sure
if you can get them anymore though.