[TowerTalk] 160 inverted L

Phil Clements philk5pc@tyler.net
Sun, 12 Dec 1999 10:40:59 -0600

> Some time ago some kind person  NU9S I think  put out a number of
> responses about this subject.  I am trying to get an inverted L for 160
> going. It is over salt water of the intercoastal waterway. The previous
> posts suggested 130 feet was the best length to start. This goes up 48
> feet on a boat house and the rest horizontal. Fed at the bottom with the
> center conductor of the coax to the antenna and the braid to a 240 foot
> counterpoise at 3 feet above the water along the pier directly below the
> antenna. At 130 feet total it resonated at 1.58 kc. I cut off 3 feet and
> it resonates at 1.6 kc. I cut off  4 more feet and it moved up only to
> 1.625. Am now at 122 feet!! Some where I read 127.5 feet was supposed to
> put me at  1.9 kc. .   Looks like I will have to cut off alot more
> before I get to 1.9 kc. Am I going in the right direction? Was 130 feet
> too long  to start with over salt water?  Shall I keep on cutting  until
> I get to  1.9kc ?   The coax  is 350 feet long out there. Any help will
> be appreciated.
> Dick W5AA
Hi Dick,
Put up the length of wire that is resonant by the formula for the frequency
on interest. Then cut the counterpoise to resonate the system, not the
antenna wire. I would install a choke balun at the feedpoint to keep the
shield of the coax from acting as another counterpoise.

Phil, K5PC

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