6BQ5 Bias Point Help

[Troncones]

Is there a better way to determine bias point and grid volts for different Vg2 volts besides looking at the Vg2=250V curves and guessing?

 

[Tom Bavis]

Use the triode curves and you'll be close, since the current will only go up slightly with higher plate voltage.

 

[artosalo]

Is there a better way to determine bias point and grid volts for different Vg2 volts besides looking at the Vg2=250V curves and guessing?

Sometimes I have made pure experimetal tests by having all variable voltages (supply-, g2- and -g1-voltage) for a tube under test and also variable load resistance.

Then all required combinations can be tested and the results are fully "live".

I see this as the best way if not suitable data is available.
I have used this method for some soviet-made output tubes with good results.

Ofcourse this requires that one has some test equipment available.