Towertalk
[Top] [All Lists]

Re: [TowerTalk] Vertical dipole other choices?

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Vertical dipole other choices?
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Thu, 22 Oct 2020 11:33:52 -0700
List-post: <mailto:towertalk@contesting.com>
On 10/22/2020 8:18 AM, Ron Hill wrote:
The vertical dipole is about 60' horizontally from the tower so I would
suspect little interaction.

That's NOT a safe assumption. On the advice of two very smart guys, I did NEC modeling to investigate interaction on 160M, and found enough interaction to show that my tower gave me more than 2dB of gain to VK/ZL using my Tee vertical (with a null to the north), with a separation of 200 ft. N6LF has published work showing that even relatively short towers (and other objects) can cause interaction, both good and bad.

My ground here is very poor - Sandy gravel down to hard pan at 60' depth.

I have similar conditions here. The only band on which I find verticals effective is 160M, and that's because any horizontal antenna I can rig is low as a fraction of a wavelength.

73, Jim K9YC

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>