[Amps] screen grid current question on gu-84b

[ka1mwp]

I assembled the amp over the last few months using the TETRODE boards. 
Info:      plate voltage = 2350
            Grid 1               -65v
            Grid 2               365v
RF        Input                 50ohm to ground
 
You can see the schematic at
 
http://home.comcast.net/~ka1mwp/gu84b_hf_amp.htm
 
question is.
 
Bringing the power up after going thru the tank circuit calculations
(they could be off ) first pass.
 
I'm watching the bleed current thru the 30k 10w bleeder. ( the current
meter is adjusted with shunt to read 10ma 
I marked the face scale at that point to make it zero) When I apply
power (10w or so) I see  the screen grid current 
Which is to cathode (ground) drop
Down to either zero or negative. I read someplace that it takes some
amount of power in to get the current to start
Going positive? I'd like some clues to help me understand what might be
going on here. This is with 10 watts in
And I'm getting 3-400w out at this point..I can vary the tank vacuum
caps and it makes no difference. in other words
Slightly off tune the tank..i'd like to keep pumping in the RF power but
at this point I'm stopping. I'm doing this
With the ALC disconnected from the boards.
 
Thanks. Let me know if I am explaining this correctly, I tend to run on
LOL
 
KA1MWP