Hi Marlon,
How tall will the towers be? If you're looking at 120 ft or less you might
take a look at AN Wireless.
73, Glenn/.KD0Q
----- Original Message -----
From: "Marlon K. Schafer" <ooe@odessaoffice.com>
To: <towertalk@contesting.com>
Sent: Wednesday, April 29, 2009 11:00 AM
Subject: [TowerTalk] tower advice and suggestions
> Hi All,
>
> I'm working on a grant application for a network expansion and I could use
> some advice on the towers.
>
> Our ground out here is either sandy, solid rock, soil (farm ground) or
> soil
> and rock mix (also farm ground :-P).
>
> I'll want the ability to put a distribution omni near the top (basically
> no
> wind load), 3 sector antennas roughly 8" by 6" by 2'. Around half way
> we'll
> want to run backhaul antennas (don't need to go to the top because we'll
> have the towers no more than 15 miles apart). The backhaul antennas will
> be
> 3 3' dish antennas and 3 2' dish antennas per tower. There will also be
> the
> radio units themselves and those boxes are about 1'x1'x4" on average. So
> there will be from 6 to 15 of them per tower.
>
>>From talking to my rep at Hutton it looks like there are two pretty good
> choices for me. Both free standing towers and mono poles.
>
> The free standing towers would make it easier to add things like ham
> repeaters, public safety systems etc.
>
> The mono poles are nearly half the money. I don't know what the cost of
> mounting accessories would add though.
>
> I do NOT want to use guyed towers if I can help it. No matter what I
> always
> seem to end up with a link that has to shoot through the guy wires. grrr
>
> We're in a 70mph wind zone here, though I've seen it hit 100 in the last
> few
> years. No tornadoes etc. though.
>
> What would you guys use? What factors affect your decision making
> process?
>
> And FYI, the motor home emergency communications project is coming along,
> slowly but it's moving. We did use it to provide free internet to people
> at
> a couple of motorbike races about a month ago. I learned that 3 group 27
> batteries take a LONG time to re-charge once they've been pulled
> completely
> down. And they go down at a surprisingly high rate when you leave the
> furnace on in a 29' motorhome! Using the DC charging port on a Honda 1kw
> generator only give you 8 amps of charge. But the 4kw (built in and much
> noisier!) unit will charge at 45 amps! Even with BOTH running it takes
> the
> better part of 4 hours to bring the batteries full up to speed.
>
> I've decided to install a 3' x 16" x 3" weather tight box on top of the
> motorhome. I'll run a conduit from the cupboard that the radios will be
> in
> to the box on the top. That will allow us to easily make changes to the
> antennas without having much to worry about when it comes to water getting
> into the coach. It'll also leave the inside looking as un cluttered as
> possible and that'll be a good thing for momma!
>
> The mast I built onto the coach (mostly for my backhaul high speed data
> antennas) turned out to be pretty easy. I built a couple of brackets that
> attached to the back of the coach (lag screwed into the solid wood
> framework). They have u-bolts welded on and are painted body color so
> they
> don't look bad at all. I then used a mix of galvanized EMT, fence pipe
> and
> aluminized exhaust pipe. I welded nuts to the largest pipe (two of them,
> 6"
> apart), I made a couple of t-handled bolts to fit the nuts. The middle
> pipe
> and the top pipe are able to be pinned (with captive spring pins like
> you'd
> use on a trailer hitch to keep the couple from rattling loose) at pre set
> heights. I painted two bands on the inside pipes so that I could tell
> when
> I was about out of room to push them up.
>
> All pipes fit with almost no clearance, just enough to slide them up
> easily.
> The inside most pipe is 2" o.d. so everything is strong enough that I
> don't
> have to guy it, even with 2' grid antennas (two of them) on it. I didn't
> put the system all of the way up this time, and I didn't have both
> antennas
> at the very top. But we did have 40ish mph winds and there was NO sign of
> anything loosening up and no damage to anything at all. I can take this
> system up to nearly 30' above the ground and it still collapses small
> enough
> that I can store it underneath if I choose to! If it's left on the coach
> there are NO tools needed to raise and lower the mast and it can be turned
> 360* once it's up to the height that I want it at.
>
> At some point I may drill some holes in the second pipe so that I can
> raise
> it then pin it before tightening the t-handled bolts. This would make it
> quite a bit easier to aim the antennas when needed, now I have to hold
> everything up and turn, then tighten. I may also add a brace from the
> bottom bracket to the bumper so that I can confidently stand on the upper
> bracket while working on things. I don't think I've even got $100 into
> the
> mast so far!
>
> laters,
> marlon
>
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>
>
>
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