[Amps] 4-1000 Bias

[Wayne Rogers]

I have a 4-1000 g-g homebrew amp.  It was designed 4000 volts on the plate. 
My new supply is 5500 volts under load.

With the grid at ground potential and at 4000 volts on the plate the no 
signal grid current is 40 mA. and the plate current is 170 mA, which seems 
right.

At 5500 volts on the plate and the grid at ground potential Ig is 80 mA. and 
Ip is 300 mA. which seems a bit high. My plan is to add bias to the grid. 
How do I determine what the correct operating point is for grounded grid? 
At 300 mA. I'm dissipating .3 X 5500 = 1650 watts which is way over the 
tubes rating.

Thanks,  Wayne N1WR