[Amps] What Is TheOptimum Bias For GS-35b Tubes?

[Mel]

I have a GS-35B Bias question.
I constructed a 2 tube GS-35B amplifier; it has separate filament transformers and bias systems for each tube.  My transformer runs 4200 VDC unloaded; I set the Zsac for each tube separately, I have each tube running at exactly 425 mills at idle.  At 425 milliamps, the X-former drops to 3900 VDC (with one tube disabled by removing cathode fuse).   Both tubes are set to draw the same amount of current.
 
When I put both tubes in service, instead of getting 850 mills of Zsac, my idle current is 740 milliamps and my B+ is at 3750 VDC.
 
With RF drive the B+ dropped to 3375 VDC @ 2.0 amps and delivered around 4000 watts output; at increased drive levels, the B+ did not drop any lower than 3375, it  (the X-Former just drew more current from the mains; I took plate current up to 3.5 amps and B+ held solid).
 
What’s the optimum level of bias to run on a GS-35B and, based on my observations, should I crank my bias up a little higher in setup knowing that when the 2 tubes are run together they drag the B+ down which changes the affect of the bias setting?
 
There is a lot of information at GS-35B DOT com but, I would really like to hear from someone with recent experience on their construction / conversion using the GS-35B tube.
 
koØm
 
http://www.network54.com/Forum/142608/
 
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