From: "Will Matney" <craxd1@verizon.net>
> Class AB, K = 1.5
My understanding is that this value of K applies to triodes, where Ep can swing
nearly to zero. For tetrodes, Ep cannot swing below the screen voltage. IIRC,
this has the effect of increasing K.
It's useful to consider the consequences of slight errors in component-value
selection. Assuming your variable controls (plate tuning and loading) have
enough range to get a close match, the negative consequence would be a Q
different from what you calculated. But if you give yourself enough range in
tuning and loading Cs, you should be able to tune for _best linearity_ (more
important than best efficiency) and still get enough Q to reduce harmonics
below FCC requirements.
If you calculate a range of plate loads by varying K from 1.5 - 1.8, and then
calculate tank circuit values based on a Q range of 12-15, you should come up
with tuning and loading cap values that will do the job.
73,
Jim, KR1S
http://kr1s.kearman.com/
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