Hi Bill,
> Previous posts indicate that the numbers Rich used below were NOT for a
> G2DAF Amp, but for a "bastardized" version. Rich has a "Thing" against the
> so-called G2DAF, and his comments are to be taken with caution.
>
> Bill-W4BSG
I don't think the G2DAF is a good system either. It has to be, at
the very least, very unreliable for IMD quality.
It does everything wrong I can possibly imagine. It loads the exciter
with a time-varying and power sensitive load, the screen voltage
moves all over the place, and there must certainly be phase-shift
between the screen voltage and the drive voltage.
Probably the only thing that "saves it" in some cases is the high
amount of negative feedback.
I'm sure there are cases where it will work, but then I've even seen
class C PA's produce "acceptable" IMD at certain power levels and
certain tuning conditions.
IMO, the fewer G2DAF systems on the air the better off we all
are....even if some seem to be "OK". It has to be one of the
poorest circuits available for a linear amplifier, short of out-and-out
self-biased class C.
73, Tom W8JI
w8ji@contesting.com
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