[TowerTalk] Tall verticals

[Eric Gustafson]

Hi David,

See my comment below.

>From: "DavidC" <eDoc@netzero.net>
>Date: Wed, 10 May 2000 09:56:43 -0400
>
>> > You specified "tall" towers.  What about a 65 foot Rohn 45
>> > tower with tri-banders at 45 and 70 feet?  Would the side-
>> > mounted beam problem be as pronounced on that?
>> > 
>> Probably NOT.  It should work OK on 160.  Forget 80M.  Use a
>> separate vertical.
>
>So, it would be about a 1/8 wave on 160?
>
>Why would it not work as a 1/4 wave on 80m?
>
>If I insulate the side-mounted beam by covering the mast with
>PVC will its proximity, even if electrically islolated, cause a
>problem?

How do you plan to effectively isolate the feedline for the
insulated beam from the vertical radiating system?  If you can do
that, it will probably work OK.  But it might raise lightning
damage control isues.  If lightning isn't a big concern at your
site, this isn't a big issue.

73, Eric  N7CL


>
>80m is far more important to me for emergency communications
>than is 160m.  Are there changes in the configuration of the
>tower and antennas that would make it more suitable to 80m use?
>Must I eliminate the side-mounted beam entirely?
>
>> > I want to load it for 80m and want to make some choices
>> > about the type of base I use, where and how I side-mount
>> > antennas and anything else that may impact performance on
>> > 80m.  I have the tower but the pouring of the base has yet
>> > to be scheduled.
>
>- Thanks! & 73, DavidC  K1YP in Hudson, FL

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