> mounting hardware. I would not use the Pi-L numbers in
> the ARRRRRRGGGL
> handbook as they have been wrong for years,IMHO.
Bob,
Are you sure the ARRL handbook is wrong?
There are many reactance combinations that will work in that
circuit configuration. There are many combinations with the
tuning and loading caps at about a 2.5 ratio that work.
For example, a double L Q of 4 and an intermediate impedance
value of about 1400 ohms will produce about that ratio. So
will a pi tank Q of about 20 with an intermediate impedance
of 500 ohms.
As a matter of fact you can use a 2.5 ratio and by setting
the ratio of the two inductors move the tank Q all over the
place. The higher the Q, the lower the intermediate
impedance has to be. The lower the Q, the higher the
intermediate impedance has to be to maintain a 2.5 ratio.
If Sunair sold amplifiers that worked (and I would bet they
did) they probably optimized the networks for that
application. They didn't reach around to a place near their
back pockets and pull a Q and tell the rest of the world
that would be the only Q that works. If they said the ratio
was 2.5, I'd bet money that ratio is optimum for their goals
which would be bandwidth and harmonic suppression
requirements.
I don't understand why so many people think there is only
one combination that "works", and why we go through so much
trouble to obtain a "Q" that at best is just a wild guess of
an optimum value. What do we think, only one Q value will
work?
73 Tom
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