If the trees are so close that it turns vertically but not horizontally,
that will only last about 3 months, then he won't be able to turn it
mounted vertically.
Besides if the antenna is very low, mounting it vertically will loose a
lot of gain. For example, over average ground a 3 element Yagi at 40 ft
might produce 12 dBi gain at 24 degrees take-off angle. The same
antenna turned vertically will produce 6 dBi gain at 12 degrees
elevation (or 3.3 dBi at 24 degrees elevation). The vertically mounted
antenna will have a much wider lobe in the azimuth direction (about 50%
wider).
The higher the antennas are, the less difference in gain there will be
between mounting vertically and horizontally. If it is over salt water,
the answer will be considerably different.
Then there is the mast interference problem to solve.
Jerry, K4SAV
Robert Pack, NX5M wrote:
>The only thing he is going to gain is being able to put something up that he
>can turn. He cannot go high and he has tree issues that prevent him from
>turning it if it is horizontal.
>
>----- Original Message -----
>From: "Mark Robinson" <markrob@mindspring.com>
>To: "Robert Pack, NX5M" <nx5m@txcyber.com>; <towertalk@contesting.com>
>Sent: Tuesday, June 19, 2007 7:41 PM
>Subject: Re: [TowerTalk] Trapped Tribanders Turned Vertical
>
>
>
>
>>What does he hope to gain by mounting the tribander vertically?
>>
>>
>>Mark N1UK G3ZZM
>>
>>
>>----- Original Message -----
>>From: "Robert Pack, NX5M" <nx5m@txcyber.com>
>>To: <towertalk@contesting.com>
>>Sent: Tuesday, 19 June, 2007 8:00 PM
>>Subject: [TowerTalk] Trapped Tribanders Turned Vertical
>>
>>
>>
>>
>>>Without going into great detail with the reason this question is being
>>>asked......local guy wants to put a tribander up (an A3 I think) and
>>>wants to mount it vertically. He asked me what I thought about it. My
>>>first thought was water getting into the traps and not draining out, or
>>>draining out too slow.
>>>I have never seen a vertically mounted tribander (other than triband or
>>>better verticals). I will admit that I have never looked closely at a
>>>trapped vertical so I do not know if there is anything different in the
>>>sealing of the traps or not. Is there?
>>>
>>>Could this fellow actually put his three element tribander vertical?
>>>Should he seal the top ends of the traps and maybe put small pin holes on
>>>the bottom ends so water can drip out? Any electrical or structural
>>>issues that come to mind?
>>>
>>>I will print and pass along all replies.
>>>
>>>Thanks.
>>>Bob NX5M
>>>_______________________________________________
>>>
>>>
>>>
>>>
>>>
>
>
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