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Re: [TowerTalk] Obstruction Lighting

To: "Doug Rehman" <rehman@surveil.com>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] Obstruction Lighting
From: "K8RI on Tower talk" <k8ri-tower@charter.net>
Date: Tue, 5 Jul 2005 15:55:07 -0400
List-post: <mailto:towertalk@contesting.com>
You need lighting on a 54' tower? (70' over all)  You must be almost right 
along side the runway or within half a block off the end of a runway. 
Normally, you'd almost need to be on the airport property if you aren't 
right off the end of a runway.  As I recall, there is a clear zone right off 
the end and then it goes to a 20:1 slope which starts at the end of the 
runway. Beyond some specific distance it goes to 100:1 up to 5 miles from 
the end of the runway.  I've been trying to find these distances and ratios 
in the FARs or AIM, but nothing so far.  We have 2 and 3 story houses within 
a city block off the south end of 18/36 at 3BS.

If you don't mind me asking, what field are you near?  You can e-mail me the 
designator and details if you wish.  I'm interested in why they'd require 
lighting on a 70 foot installation.

The regulations on lighting can be a royal pain as if you have reached the 
point where the FAA (not the local government) says you need to light the 
tower, then you have to notify the FAA every time the lights are off and you 
only have a short time in which to do so.  Then it is added to the Notice To 
AirMen (NOTAMs) so it comes up in preflight briefings. in the following 
form:
Pinconning MI (Gross) [52I]: July NOTAM #25 issued by Lansing MI [LAN]: 
Tower 910 (300 above ground level) 1.76 east-northeast lights out of service 
(ASR 1005779) until July 17th, 2005 at 11:48 PM EDT


> Due to my proximity to a small airport, the FAA is requiring obstruction
> lighting (L-810 light or lights) on my tower; painting is not required
> though. The tower will be a Tri-Ex LM-354HDSP 54' crank-up with 15' of 
> mast
> out the top.
>

My system is directly on the centerline for the approach to 06 and just a 
tad under 5 miles out so I fall in the 100:1 and could go to just shy of 200 
feet without lights.  I'm at 130.

One night I head a helicopter sounding quite close.  I could see their 
running lights were well below the top of my tower and within a few hundred 
feet.  There was a sherrifs car near my driveway so I hurried over and 
pointed out the tower.  They assigned a car to set there with their spot 
light on the antennas.  They were hunting for an elderly lady who had walked 
away from a health care facility.

> 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.
>
> The next decision isn't quite as easy to make. I can use a standard 110 
> VAC
> light that costs about $120 or a 12 VDC light that costs $223 (Dialight
> model 860-1R03-001 from www.unimar.com). Either option only requires a
> couple of amps.

Even with a couple of amps at 12 volts you wouldn't want to go far.

>
> I will have mast mounted preamps for 6m, 2m, and 70cm mounted at the top 
> of
> the tower, so I need 12 VDC there anyway. I could run 110 VAC to a NEMA 
> box

You are probably going to want the 12 volt supply up there any way which 
means running the 110VAC  up there as well.

> with a 12 VDC power supply in it to feed the preamps and use the 110 VAC 
> to
> feed a standard L-810 light. A heavy outdoor extension cord, or stranded
> THHN, encased in flexible conduit would be used to run the 110 VAC to the
> top. The tower will already have 110 VAC at the base to run the winch.
> Alternatively, I could use the more expensive 12 VDC L-810 light and just
> run 12 VDC to the tower top for everything; running the preamps and light
> from a trickle charged battery would provide for emergency power.
>
You must be in a warm climate.

> I'm leaning strongly towards the last choice (all 12 VDC on the tower), 
> but
> looking for input from the collective wisdom and experience of the group
> before committing.

Me?  I'd go with the 110VAC in metal conduit to the top, but right now I 
think I'm going to go to 3BS and do some flying.

Good Luck,

Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com


>
> Thanks,
> Doug
> K4DDR
>
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with 
> any questions and ask for Sherman, W2FLA.
>
> _______________________________________________
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> 
_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

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