antenna tower

[wingnut]

No cable in our rural area (naturally) and thus I have a BUD (big ugly dish) satellite system. However, for local stuff, I need an antenna and stuck one up on a 20 ft mast - with some 5 feet being above the roof. I want the local antenna higher.
Last year I finally found a used tower (new ones are ridiculously expensive) and over the winter I cleaned all the rust off (wire wheel ... lots of work!) and this spring I primed and painted it. It's ready to go up ... but ... I'm wondering about the adviseability of what I'm planning. Because the planned spot MAY have water and electrical lines under it ... at some unknown depth ... out to the barn, I thought I would anchor the base by putting up a box form, on the ground or maybe at most 6 inches deep, standing up (and securing the tower) in the form and pouring about a 18" to 2' block of concrete. The upper part of the tower will be fastened to the house with a standard mast/tower bracket ... and maybe even an additional bracket to the deck fence on the side.
Would a solid concrete "block" approximately 2x2x2 adequately support the tower (standard triangular 30ft pipe style) with the bracket? Or would I also need to consider guying the structure?

pete

[gws]

How tall you going up, what height? What type of tower. There are cheap alumium and steel towers that looks the same but are very different.

The proper way to do it, is to dig a 3ft hole, place a concreate mount or part of an old tower into the concrete. Add some rebar and fill with concrete.

A few inches in not enough to keep a tower safe. If your only going up 30ft or so then maybe it will work. If your getting over 40ft then you need a lot of base to handle the wind and vertical load. Even bolted to the house you need lots of counterweight.

[GaryM]

Depending on where you live, you may need a permit. If so, they may want you to use the manufacturer's specifications. Even if you don't need a permit, you want to be sure it's done right.

Attaching the tower to the house does one of two things. You can go higher without using guy wires, or you can use a bigger antenna (windload).

If it's a Rohn 25G or similar, the mounting specs are available on the web. Likely the same for others.

Rohn 25G, which is a small tower, specs a hole 4'x4'x4' with #7 rebar embeded. As mentioned, you'd normally have a 5' section of tower embeded in the concrete. Rohn normaly comes in 10' sections.

[pbenven]

We installed a 60' tower at our hunting camp for a CB. It's made up of 12' sections. We drilled 2 holes near the bottom of each post on the bottom section. We used these to attach 4' pieces of angle iron to each post. We dug a hole about 3' - 4' deep (pear-shaped) and stuck in the angle iron end of the assembly. Held it vertical and poured in concrete. Now, to raise or lower the tower, we remove the bolts from the "back" post and one from each "side" post, leaning it down slowly with 2 block and tackles.

No guy lines. No support brackets. Just the footing and it's holding well - but this is for a mono-pole attenna. I have seen 45 footers done in the same way for TV, though.

[Hank]

<font color="purple"> Depending on where you live, you may need a permit </font color>

I kind of thought a HAM or two would chime in here [img]/forums/images/icons/wink.gif[/img]

[GaryM]

I'm getting ready for next weeks appearance before the planning board. I've submitted a permit application for a 70' guyed tower. I'm getting my answers together for any questions or objections.

This weekend I need to measure the height of some trees to compare to the height of the tower.

[Hank]

<font color="purple"> I'm getting ready for next weeks appearance before the planning board </font color>

What do you plan to mount way up there? rotor?

[GaryM]

Ham II rotor

Force 12 XR-5 (10M, 12M, 15M, 17M, 20M 10 elements)

M2 6M5X (6M 5 element)

M2 2M12 (2M 12 element)

And a Comet 6P dual band vertical

That out to do it.

The Ham II rotator is marginal, but i have it so will use it until it fails.

[jray]

Your Local utility will probably came out and locate your lines for you. When I ran electric and water to my barn, the utility sent a contractor out and lcated my phone electrical lines for no charge. [img]/forums/images/icons/grin.gif[/img] Thanks Jray

[wingnut]

30' tower .... and I was (also) trying not to make it less than 30 ft by dropping it too far in the ground. Don't know the make ... it was used - well used - and doesn't have any markings on it. It's rather compact compared to what I used in the past for a Moonraker (last time I used a tower - 25 years ago) ... triangular with about 15" sides. Straight with only about 3 feet at the top narrowing to a point.
Where I'd planned to put it, it would be attached to the deck at 5' and to the house at about 18-20'.
Since I'm in the country ... I'm on a well and that's why I'm afraid of running afoul of the water line to the barn. I know where it exits the house and the chances are 50/50 that it runs inside the "envelope" of safety .... and I'm assuming they put the power in the same trench ...
"All" that will be on the tower is the deep finge antenna with a rotator, as well as (lower down) my Davis weather station that's still (after a year) sitting all boxed up. Anemometer and rainfall gauge.

pete