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I saw an article on something like this myself, There was this guy that had a tower with very wide face (20 ft.) and wanted to have an omnidirectional pattern so he tried the yagi approach and actually ended up with a great omni pattern but the gain ended up being unity or slightly above due to the interaction of all the lobes of the yagis. Anyway that is how I remember the outcome.
tom n8ies
----- Original Message -----
Sent: 3/29/2005 10:44:00 PM
Subject: Re: [Repeater-Builder] Re: A Good 440 Antenna
Skip
This type antenna setup is of interest to me. We have our repeater antenna atop a 150 ft water tank but the cell antennas have taken over. The owner told us we would have to live with the cell people as they were paying customers and we aren't. My idea is that we could use four yogis around the rails with the power divided into four equal parts with the yogis fed in phase and get somewhat a round radiation pattern. Any info as you said would be greatly appreciated.
Thanks.
de Tom Manning, AF4UG
skipp025 wrote:
re: Multiple feed antennas around a tower:
This type of antenna was written up in Ham Radio
Magazine (rip) some years back. I just thumbed
past it the other day.
The math and the information to cover around a
large tower with a quasi Joni pattern using
directional antennas was shown.
If I see it again, I'll scan it and send it
in. I sure miss Ham Radio Magazine...
skip
Mike Morris WA6ILQ <[EMAIL PROTECTED]> wrote:
Years ago I saw a weird situation - a pair of 4-bays
on opposite sides of the tower, fed by a KM 2-port
power splitter. Later at a different site I saw a custom
pattern engineered with a 4-port splitter and 4 beam
antennas.
How they kept them from interacting and screwing up
the pattern I'll never know...
In your case you might be able to mount the dipoles
to the tower leg itself, perhaps with some magic
distances to get an Joni pattern. This would leave
the top of the tower bare ... let the tower itself be
the lightning rod.
I'd measure the tower face and make up a drawing
showing the 4 sides (or 3 sides?) of the tower, and
your mounting concept. Then contact the engineer
at the antenna company (via email or phone) and fax
the drawing to him and get his ideas.
Mike WA6ILQ
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- Re: [Repeater-Builder] Re: A Good 440 Anttena Thomas Oliver
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