From: "Will Matney" <craxd1@verizon.net>
> I'm not knocking using 1.8 as that's what I use and it works. The reason I
> broought all this up is that they do not make it clear from what I read that
> these factors are for triodes only that I seen.
I suspect that when that section was written, the League was publishing only
triode amplifiers. For many years until George Daughters published his 4CX1600B
amplifier, all Handbook amps used triodes.
I got the insight into the differences from reading Rich Measures's site. It's
interesting to read the history of his Handbook chapter, which was presumably
rejected mainly for political reasons. As load impedance calculations are based
on the plate-voltage swing, it seems intuitive that the k factors for triodes
and tetrodes/pentodes would be different.
> Also, the terms differences that
> we use where they say the plate load resistance is the same as plate
> impedance.
Assuming the load is matched, the plate is looking into a non-reactive
impedance, so the terms could be interchanged. Considering the load as an
impedance, though, is more in line with the fact that we are dealing with ac
and reactances, not dc and pure resistors. My guess is the confusion stems
mostly from erratic editing of the Handbook. Certain chapters are chosen for
revision and updating each year. Other chapters, even though they may contain
known errors, are not touched. It might pay to take several years' worth of
Handbooks, cut them up, and reassemble them to produce one relatively
error-free copy!
73,
Jim, KR1S
http://kr1s.kearman.com/
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