[TowerTalk] Trapped Tribanders Turned Vertical

[Roger (K8RI)]

> 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

Don't forget to subtract for the metal tower stuck between the elements. At 
least I'd think it would have a detrimental effect.

Roger (K8RI)


> 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 at mindspring.com>
>>To: "Robert Pack, NX5M" <nx5m at txcyber.com>; <towertalk at 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 at txcyber.com>
>>>To: <towertalk at 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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