At risk of having missed something obvious why is it that once you have measured the voltage across the screen resistor, it then neccessary to use the voltage between screen and cathode to calculate resistor dissipation at idle? Can't you just square the voltage and divide by Rsc?tubeswell wrote: Measure the (quiescent) voltage drop across each resistor, then divide that by the actual DC resistance of each resistor, and you will get the screen current at idle (its likely to be somewhere between 2mA - 4mA or in that ballpark) Multiply this screen current by the voltage between each screen and the cathode and you will get the dissipation of the resistor at idle. Double this dissipation value to get a 'safely' rated resistor.
Proper type of switch for choke/standby/resistor setup?
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