Plexi bias

[JoeCon]

Guys

So my 6V6 Plexi is my first fixed bias build. I tried EL34's in it and want to be sure I set the bias correctly.
EL34 25W/420V (plate voltage) = .059mA
.059mA x .7 (70%) = .041mA.
So setting my bias pot to read .041mA(mV) across my 1 ohm resistor gives me the right bias for the tube...yes?

Thanks.

[martin manning]

Correct but I'd do it direct: 25W*0.7/420V = 42mA
You'll be less than 70% because you are measuring cathode current which includes screen current, which is maybe 5% of the total.

[JoeCon]

Martin,

Sir, Thanks. So I could float up another 5% and still be "kosher". Excellent...

[roberto]

You can add around 5 mA and still be on the safe side.

[RockinRocket]

Is this way the most accurate way to bias?
https://robrobinette.com/Tube_Bias_Calculator.htm
Plate to cathode voltage( Plate volts minus cathode volts)
And does this require a 1ohm resistor from pin 8 to1 to ground? If not will one there affect the results of this method?

If im not mistaken Jocons method is the one from the metro kit pdf?

[JoeCon]

Rockin
I measured the OT voltage at the tube socket. I knew the EL34 was a 25 water from tube data. I have a 1 ohm 1% resistor that I monitor for setting the bias.
I was lucky my bias supply will do both 6V6 and EL34's no problem.