"Frank" wrote in message
news:1Iw6l.480$PH1.385@edtnps82...
There are some in our group who really, REALLY think that the vertical
is the way to go, and I need some debating points. So, if I had a
decent ground-mounted vertical, should I expect to get the ground wave
distances that G4FGQ indicates in his calculation program?

Is there any area / radius that would be covered by a ground-mounted
vertical that wouldn't be covered by an NVIS horizontal (assuming that
we're operating below the critical frequency)? I have always assumed
that by the theory behind NVIS, the answer would be no... NVIS should
cover everything out to a radius well beyond groundwave distance.
But, I suppose we could install NVIS antennas AND verticals and switch
between them to see which one works best at any given time. Does seem
to be a wasted effort but WDIK?

While I'm at it, how do I estimate antenna efficiency? What is the
average range of efficiencies normally seen with a quarter-wave
ground-mounted vertical, with an adequate ground radial system, in
average soil?

Note that radiation from the end of a low dipole is vertically polarized.
Antenna efficiency, and surface wave field strength, can be computed
with NEC.

Frank, VE6CB

Given the type of antennas you mentioned with 100 W. If they are facing end
to end,
and, over an average ground, you should expect: 21uV (S7 - 8) at 20 mi, and
14 uV ( S6 - 7) at 30 mi. If the antennas are parallel then the signals
will be
10 db weaker. I used NEC for the analysis.

Frank