[Amps] 4CX250B Ratings in Dentron Clipperton V

[Jim Brown]

I've just fired up a Dentron Clipperton V modified for 6M operation per 
Dentron instructions. It uses a single 4CX250B in Class AB2. The bias is 
adjustable, and the factory recommends 50mA plate current with no signal. It 
takes about 15W to give me 250W-300W out. 

My question is about power ratings. I want to use it on both CW and SSB. How 
hard can I push it without damaging the tube on SSB? The DC current rating is 
250mA. In SSB mode, I can get 200W indicated on a Bird with an indicated 
plate current of 200 mA or so (this is with modulation, not tune-up). I'm 
tuning up with high speed dits, so that I should be tuning for that peak 
power. Is this a reasonable way to run it, or am I pushing too hard? 

When I run CW,can I increase the envelope power on CW if I stay below 250mA 
average current (as indicated on the plate meter), or do I need to stay below 
250mA when I tune key-down?   Can I change the bias to get more than 250W 
out, or do I need to make other changes to the circuit to change the load Z?  

73,

Jim K9YC