You can work DX with almost any antenna. N6BT worked all continents in two
days running 120 watts to a light bulb.
Some people enjoy building their station and maximizing their signal. K6UJ
asked what was the BEST height for a 15m yagi for contacting someone 6000 miles
away. Unfortunately there is no single best height, as conditions vary.
73,
John KK9A
----- Original Message -----
From: David Blake
To: john@kk9a.com ; towertalk@contesting.com
Sent: Friday, March 02, 2012 17:39
Subject: Re: [TowerTalk] 15 meter yagi height for 6000 miles
John et al-
All this may be true to some extent but the majority of us don't have the
option of stacked
HF yagis at 90' HI.
I have never had an tower higher than 48 feet yet somehow have managed to
work ALL DXCCs (#1 Honor Roll). and all 40 zones
on 6 bands. Over 300 DXCCs on 6 bands, etc, etc. My point is that you can
do a lot with antennas at much less than what some
computer program says is optimum.
As Bill Moore says on the LoTW page, "Go work some new ones."
73, Dave -N4DB-
------------------------------------------------------------------------------
From: "john@kk9a.com" <kk9a@bellsouth.net>
To: towertalk@contesting.com
Sent: Friday, March 2, 2012 10:36 AM
Subject: Re: [TowerTalk] 15 meter yagi height for 6000 miles
To get the main lob at 3 degrees the antenna would have to be 200' high
(assuming flat ground). This is a poor choice since it leaves a big null at 7
degrees. I have had good results on 15m with a single yagi around 90 feet
high. Of course stacked antennas are the ideal choice.
John KK9A
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 15 meter yagi height for 6000 miles
From: Jim Lux <jimlux@earthlink.net>
Date: Thu, 01 Mar 2012 18:24:18 -0800
Here's the antenna book data for LosAngeles to EU (LA to Paris is about
6000 mi). It looks like you want an angle around 3-5 degrees, and maybe
a bump around 8-10 degrees. These numbers come from VOACAP, I believe,
so you could get a copy of that load it up, and run it for your link.
HFTA would then tell you how high to make the antenna to make that first
big lobe at 3 degrees.
Los Angeles, Ca to Europe
Elev 80m 40m 30m 20m 17m 15m 12m 10m
1 2.5 6.6 4.1 6.8 4.8 1.8 0.0 0.0
2 4.1 9.1 10.8 6.7 9.6 4.9 4.6 5.6
3 4.2 7.0 15.3 13.7 17.5 20.2 6.2 0.0
4 10.2 11.2 10.8 7.8 13.6 13.5 9.2 0.0
5 6.2 10.2 14.2 5.1 5.6 12.3 15.4 22.2
6 1.7 6.6 12.0 8.3 7.1 6.7 9.2 16.7
7 3.5 3.3 8.1 8.6 6.8 7.4 9.2 16.7
8 3.5 4.6 5.3 11.4 9.3 9.8 13.8 11.1
9 9.3 5.6 2.7 10.0 7.6 9.2 13.8 22.2
10 5.4 11.2 1.6 5.0 6.5 4.9 9.2 0.0
11 5.2 6.5 4.4 5.0 3.4 3.7 3.1 5.6
12 3.5 2.5 4.1 5.0 1.7 1.8 1.5 0.0
13 7.5 1.0 2.8 2.1 2.8 1.2 0.0 0.0
14 6.0 1.6 0.7 2.3 1.4 0.0 0.0 0.0
15 4.6 4.5 0.4 0.6 1.4 1.8 3.1 0.0
16 2.9 3.3 0.1 0.4 0.6 0.0 1.5 0.0
17 4.3 2.4 1.2 0.5 0.3 0.6 0.0 0.0
18 4.6 0.2 0.4 0.5 0.0 0.0 0.0 0.0
19 3.4 0.7 1.1 0.4 0.0 0.0 0.0 0.0
20 1.6 0.6 0.0 0.0 0.0 0.0 0.0 0.0
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