Dirtywhiteboy, I biased amp so that it would draw 40mA. That is 10mA per transistor. I originally biased circuit for 4.5 volts. But I found out that it is not long before replacing mosfets. I used part of design from the Ranger 94VHP. Also took a few ideas from the ARRL Amp Classics book section on mosfets using the 510 and 511's. Between the 2 this gave me a good place to start. I can't believe it only took about 160pF cap. across the output transformer. I usually am used to using something like 5 or 6 times larger.