[TowerTalk] Obstruction Lighting

[Gene Smar]

----- Original Message ----- 
From: "Doug Rehman" <rehman at surveil.com>
To: <towertalk at contesting.com>
Sent: Tuesday, July 05, 2005 12:06 PM
Subject: [TowerTalk] Obstruction Lighting

> My first decision is where to mount the light(s). I was planning on a
> VHF/UHF vertical on the top of the mast. If I do this, then I'm going to
> need two lights since the light couldn't sit on the top of the mast. To
cut
> the lighting cost in half, I will probably make a sidearm for the VHF/UHF
> vertical to mount on pointed downward, thus allowing the light to sit on
the
> top of the mast.
>
Doug:

      When you mount a vertical antenna in the inverted position as you are
contemplating, you need to allow for drainage of any accumulated water from
within the radome.  (There is probably a small hole near the bottom/mounting
bracket of your selected antenna for this purpose for normal mounting.)
Take a look at the construction of your selected model and see if you can
drill a small weep hole in the cap, etc.  Also, take care to seal off the
coax connector to minimize water ingress in the first place.

     An alternative would be to mount the vertical normally, but on a
sidearm BELOW the tower top.  Radiation center of the antenna is the same
either way, but you don't have water infiltration to be concerned about.

73 de
Gene Smar  AD3F