[TowerTalk] VHF antenna orientation

[K7LXC@aol.com]

In a message dated 97-08-29 00:46:25 EDT, you write:

> > Here's an easy one. I am about to install a 10-ft vertical antenna for
>  > 2-meters. If I were to install it at the top of my tower, it would
>  > interfere with the lowest rotating antenna only two feel above. My best
>  > friend insists that it can be installed upside-down without any negative
>  > consequences, while still giving us the height we desire. I say this is
>  > preposterous.
>  > 

     Look at the graphs of vertical antenna radiation. The big horizontal
lobes from verticals come from the bottom of the antenna where most of the
radiation takes place (the current point). Mounting it upsidedown doesn't
really change the antenna characteristics or radiation pattern. 

     Take a look at cellular installations - some omni antennas go up and
some go down. Generally the tx antennas go up and the rx antennas go down.
Mounting them like that provides additional isolation between antennas. 

    You just have to make sure that the antenna will not fill up with water.
Do a good job of wxproofing. You could even drill a weep hole in the top
(bottom) of the antenna for water evacuation.

     Go for it.

73,  Steve   K7LXC

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