My verticals on the beach use 2 elevated resonant radials and had great
results. There are lower losses because of the saltwater side but the
significant improvement IMO is due to the very low angle gain
improvement from the near and far field effects of the salt water.
Landward, the pattern is just like any similar vertical over regular
earth. Some put beach verticals up with radials in contact with the
earth, but then they are in contact with a lossy material, which defeats
much of the benefit IMO. If a "no touch" multiband radial system is a
requirement then maybe that is an acceptable tradeoff if a standard
radial complement is used. I use banana plug jumpers to make my
elevated radials quickly adaptable to 2 or 3 bands 20 > 10m. A
telescopic whip tunes to resonance, usually low 30's ohms. A CrankIR
for 40 and up.
At the North Cooks, the 160m extended CrankIR vertical performed very
well near the beach, but the single elevated radial voltages were truly
awesome. The vagaries of 160m prop are beyond my pay grade, but for 80m
I don't think there is much debate about lowest angle is best for long
haul DX.
Grant KZ1W
On 1/20/2019 10:23 AM, Wes wrote:
Personally, I don't understand all of the fuss about HFTA. In the
general case (sans 200' towers), aren't you pretty much stuck with your
environment with little to do about it?
But regarding the benefits of saltwater locations, I wonder whether they
are the result of lower angle radiation peaks or simply the increased
efficiency of the ground plane. In this query I'm considering 80-meters
and more particularly Topband, where higher angles that get through the
E layer quicker can be beneficial.
Wes N7WS
On 1/20/2019 9:59 AM, VE6WZ_Steve wrote:
...
This analysis of an 80m vertical over sloping ground certainly shows
that a significant low-angle gain benefit of up to 11dB over a flat
terrain vertical. I include a comparison to other plots from Johns
book showing how a vertical over saltwater shows a similar outstanding
low-angle response, which we have all heard in action from various
well place DX-peds on the saltwater. I extrapolate this to 160m.
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|