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Re: [CQ-Contest] Verticals on the beach (AGAIN)

To: cq-contest@contesting.com
Subject: Re: [CQ-Contest] Verticals on the beach (AGAIN)
From: Jim Brown <k9yc@audiosystemsgroup.com>
Reply-to: k9yc@arrl.net
Date: Thu, 13 Aug 2015 08:53:55 -0700
List-post: <cq-contest@contesting.com">mailto:cq-contest@contesting.com>
The best place to study this is in the early chapters of the ON4UN book, where he talks about situations like this.

Someone suggested HFTA. HFTA applies ONLY to horizontally polarized antennas.

David is right -- NEC does allow two ground models. It would be tricky though -- the key here is the sea water ending in the range of 1,000 ft. So the model would have to start with sea water out to 1,000 ft, then shift to land for the second media. That would yield an overly optimistic view of ground losses, but would take the limited sea water into account.

73, Jim K9YC

On Wed,8/12/2015 7:33 PM, David Gilbert wrote:


I don't remember for sure off the top of my head, but I think that EZNEC+ has the capability of specifying two different areas of ground conductivity surrounding the antenna. You could rather easily see the impact of the nearby salt water if I'm correct.

Dave   AB7E



On 8/12/2015 1:19 PM, Mike Smith VE9AA wrote:
As we continue to look for land around the Maritimes for a small weekend
cottage we occasionally come upon a location that has shorefront on
saltwater, which really is not completely open water all the way to EU or USA, so it's not ideal. The south coasts of VO1, VY2, VE9 and VE1 all kinda
point S/SE


I have found a couple with a clear shot to the Caribbean or Africa, but with
so few contest stations there, it's really not very important, except
perhaps for that rare LP to JA...


A few spots have open salt water towards EU of around 1000', before it hits land again (opposite side of the harbour) then gently sloping up past that.
(0-100/200 feet)


So my question is really, does 1000' of salt water make any difference at all, or not enough to make any difference and the 200' hills on the other
side of the harbour would be more hindrance than the salt water would be
helping?


There must be stations all over the world with a short salt water takeoff
who could comment?


Has anyone done any A/B comparisons or proof at all?


I have read N6LF's and K2KW's and most related stuff on the Internet, but it generally references DXpeditions in the Pacific or Caribbean with completely
open water as far as the eye can see.  I am just wanting to know about a
1000' salt water runway, then low land again.


Thanks,


Mike VE9AA/VE1TTT/VO1TTT/VO2DX


Mike, Coreen & Corey

Keswick Ridge, NB


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