Hans said:
>Series tuning a coil varies the reactance, doesnt it?
To cover 80 through 10, you need roughly a 10 to one variation in inductance.
However, the coil resistance stays the same, so the unloaded Q goes down at the
'low inductance' end - if everything else stays the same, it's reduced by a
factor of 10. Further, because the inductive and capacitive reactances are high
while the circulating current is (hopefully) the same as in the conventional
case, the voltages are very large - so dielectric losses go up, too.
Unless the series capacitor is big, you need a bigger inductor for the low end
than is the case with the conventional approach.
Not very practical........
73
Peter G3RZP
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