[TowerTalk] JAMAICA Antenna Question

[David Jordan]

Hi Folks,

Now that the F2 layer is producing some good refraction I've got a question about the NVIS Jamaica antenna.

A few years ago I built this Jamaica antenna, basically four 1/2 wave wires or two full way dipoles fed in phase and spaced 1/2 wave apart.

It was a cold day in winter when the antenna went up. I cut the wires to 70ft ea. and spaced the dipoles at 70ft. Used 600 ohm open wire for the phase line and drop to the coupler. It was easy to match on 40m.  The wires are 18ft AGL.

The antenna works as claimed when NVIS is supported by the F2 layer. Much better than a dipole at 50ft for stations within a few hundred miles. I've always wondered if it would be worth the effort to go back and prune the wires...

The question is would performance of the antenna improve noticeably by pruning the elements to resonance on 40m?
 
73,
Dave
wa3gin