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
|