It would take a wind pressure of over 750 psf to bend a 4' section of 2" SCH
40 pipe to the point of permanent deformation. 750 psf is about 30 times as
much pressure as would be generated by a 100 mph wind. Strength-wise it
would be no problem for a vhf antenna at this length. Interference-wise,
the VHF antenna is really too small to affect the HF antenna even at close
wavelength. At VHF, 4 ft is substantially enough wavelength away that the
HF antenna that it should not adversely affect the VHF performance.
KM5VI
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of David
Thompson
Sent: Friday, September 14, 2012 2:21 PM
To: Michael Zeglen; towertalk@contesting.com
Subject: Re: [TowerTalk] Antenna spacing on mast
Please don't use Sch 40 water pipe even for a VHF antenna. Exposing 4 or
more feet increases the chance of it bending in the wind. Water pipe
strength is a flow inside not outside wind strength.
Dave K4JRB
----- Original Message -----
From: "Michael Zeglen" <kl7ai@hotmail.com>
To: <towertalk@contesting.com>
Sent: Friday, September 14, 2012 2:42 PM
Subject: [TowerTalk] Antenna spacing on mast
>
>
>
>
> Want to mount my 2m - 440 small beam antenna above my Pro57B. How far
> shouuld I space it or or does it really matter as long as there is 3 - 4
> feet spacing. I realize the more the better. What do you suggest? What is
> good rule to follow. Sched 40 pipe is NO problem my son is a plumber!
> _______________________________________________
>
>
>
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>
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