First off, you 'have' measured the actual voltage with the tubes in-circuit,
correct? Just reading the voltage from the unloaded transformer will give
you an incorrect reading.

Secondly, the tube characteristics are published. Use those figures to
calculate the current draw, and Ohm's Law to figure the resistance value and
power rating for the dropping resistor. Most likely you'll need a wirewound
resistor of several watts rating.

Thirdly, if the voltage is indeed too high, you might simply place a four
amp diode in series with the transformer lead to drop the voltage to almost
the exact value desired.

Last, but not least, make absolutely sure that some other fault is not
causing the problem in the first place.

jak


rijo1 wrote:
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 ,

Ken Weitzel wrote:

rijo1 wrote:
Thanks James , I can't read the amp load because this is a Radio
Frequency circuit. Any suggestions ? Thanks ,

RF on the filaments?

Ken