Andy,

the last two pages of

http://www.cs.berkeley.edu/~culler/AIIT/papers/radio/Sokal%20AACD5-poweramps.pdf

is a nice and simple guide to the "two dimensional" tuning of the class E
amplifier. The trick is to get Vdrain make a soft landing on the right spot of
the GND runway :-)

By the way, adjusting L may be easier than adjusting C2, it has the same effect.

73
Johan SM6LKM

----

Andy Talbot wrote 2011-01-10 16:18:
> Well, the first breadboard with only vaguely correct values worked OK  - so it
> doesn't look too be all that critical.  Design Q of teh tank circuit is 5, so
> values won't be that important.   No need to tap the L measure and get it 
> right
> to start with,then use parallel C to fine tune the finished amp.    With this
> sort of Q. "narrow band" for class E probably means > 10kHz