[Elecraft] HF Verticals?

[Stuart Rohre]

Thanks for the comments Earl.  I got to typing too fast and should have
included the following:

I should have clarified that extensive modeling work by L. B. Cebik, W4RNL,
and published by him at his www.cebik.com web site, shows that CENTER FED
vertical dipoles, at the heights he modeled, do not show much effect from
the addition of ground screen under them.  I refer those with questions to
L. B.'s excellent web comments upon this point.  He has been right on with
all his modeling, and I know from personal correspondence, he checks things
with all the available programs, even the professional ones, not ordinarily
available to hams.

The bottom fed half wave, as Earl reports, certainly might suffer earth
loss.  I have not seen modeling for this case as yet.  (End feed, with and
without added ground under it).   I have not been worried about small
improvements less than a dB or 2, but certainly, some might feel those
should be pursued.

Most antennas would benefit by improved RF earth in the Fresnel Zone, but
that is out of hams control in most locations, being some 2 to 5 wave
lengths away from the antenna.  But, this area is the one you can somewhat
control by locating your antenna on the edge or top of a high location.

vertical dipoles, (center fed),  are an underexplored resource available to
hams for 20m and up, and in the capacitance hat loaded forms now being
offered, for 40m and up.  My work with 5 band models has been most
encouraging, and our lab has acquired some more from Force 12 for our HF
experiments.  I hope to build an all band model without loading coils myself
to see if there is good improvement from that effort.  I would hope to use
parallel vertical dipoles supported by the one for the lowest band.  Sleeve
feed would be possible it seems with such an arrangement.  That works well
in beams and horizontal antennas thus should be a natural for the home made
vertical.
73, Stuart K5KVH