> At 06:46 AM 5/10/2004, Steve Meuse wrote:
>
> >At 10:49 PM 5/9/2004 -0500, Lance Peterson wrote:
> >>I'm deploying an antenna on my residential rooftop for 2.4GHz wireless
> >>for a community LAN and I was wondering the best way to get 20' high
with
> >>no guy wires. Currently I am using a 3ft tripod with a 1.5 OD 10' piece
> >>of heavy wall conduit...very rigid and withstood a heck of a windstorm
> >>yesterday, but not quite high enough. Loading is minimal with one radio
> >>and a 70" antenna on top. What supports and materials would be best for
> >>this application. I was really hoping there was a 20' mast I could use
> >>that would fit in my current roof tripod that accepts 2"OD max.
> >>
> >>If I have to, I could settle for 15'...
> >
> >Try locating a fencing contractor, they usually have 20' lengths of
> >conduit that would be acceptable for a small antenna.
>
> Be very careful with this idea. In many cases not only is the top rail of
> chain link fence actually pipe with no structural rating, but also it is
> often a
> long piece of flat steel rolled into a tube and held together (?) only by
the
> galvanizing.
It's welded and very strong. At least the stuff I've purchased has been.
>
> Personally I would NEVER use fence rails--unless I knew for a fact that
> they were drawn or extruded and had a structural rating that I could
> verify.
There is nothing wrong structurally with this kind of pipe. I used it for
my Gin pole to handle loads in excess of 150# and it works fine. He's only
using it for a small antenna and most likely could even use thin wall except
for the movement..
Even the structural steel tube which extends 30 feet above the top of my
tower that supports the antenna array is rolled and welded. At least I
purchased it from a steel supplier as structural. On at least two occasions
now it has withstood winds in excess of 70 MPH.
I'd not advocate using the fence rail for a large antenna but a Wi-Fi
antenna is quite small (tiny) The size/gain is limited by regulation. .
Come to think of it, I have a 21 foot tall 144/440 duo-band vertical on one
the end of a 20 foot length of fence rail. The stuff is stronger than
schedule 40 pipe, but more springy.
Roger Halstead (K8RI, EN73 & ARRL Life Member)
N833R, World's Oldest Debonair (S# CD-2)
www.rogerhalstead.com
>
> --John W0UN
>
>
----------------------------------------------------------------------------
----
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.675 / Virus Database: 437 - Release Date: 5/2/2004
>
----------------------------------------------------------------------------
----
> _______________________________________________
>
> 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.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
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.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|