[TowerTalk] Change in Frequency As Antenna Height Rises

john at kk9a.com john at kk9a.com
Wed Jun 1 06:53:00 EDT 2016


Interesting. I trust antenna modeling but I wonder why linear loading is
less influenced by the ground.  I also wonder if coil loaded elements
react the same.

John KK9A


Re: [TowerTalk] Change in Frequency As Antenna Height Rises
from [Dan Maguire via TowerTalk]	[Permanent Link][Original]
To:	<towertalk at contesting.com>
Subject:	Re: [TowerTalk] Change in Frequency As Antenna Height

100% length (69.79 ft), no loading, +218 KHz change from 30 ft to 60 ft.
85% length (55.93 ft), 3.297 uH coils, +137 KHz change from 30 ft to 60 ft.
70% length (46.06 ft), 6.721 uH coils, +78 KHz change from 30 ft to 60 ft.

So it seems that more loading results in less change in resonant frequency as
the height above ground is varied.

Dan, AC6LA



More information about the TowerTalk mailing list