You could always try a Hygain AV-6110 for $250 bucks.
Grabbing my handy Lightning Calculator copyright 1932, I see my coil
would be about 300 microhenries and the few on line references about
such a loading coil tend to show 42 to 70 microhenries. Where my coil
would be 6" diameter and 4" long with 12 turns to the inch, a 50
microhenry coil would be 3" long, 2-1/2" diameter and 12 turns to the
inch. And if it wasn't enough inductance for resonance, it would still
definitely improve the load Z for the tuner.
73, Jerry, K0CQ
On 8/15/2010 9:54 PM, Ken Brown wrote:
Fundamentally the 43 foot
vertical is way too short for 160 and needs a BIG loading coil
containing about 77 feet of wire, and forcing that to be done in the
tuner will tend to smoke the tuner.
You are correct that a 43 foot radiator is way to short to be resonant
on 160 meters, and either an added length of wire or an inductance can
compensate for the capacitive reactance to make it a non-reactive,
resonant load. I do not think that you are correct to say that a
loading coil would require 77 feet of wire to provide the necessary
inductive reactance. Because of the coupling (mutual inductance) of the
multiple turns of the coil, the necessary inductive reactance will be
had with less than 77 feet of wire. If it is not wrapped into a coil,
then 77 feet would be about what you would need.
DE N6KB
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