I am in the process of acquiring 40 ft of Rohn 25, a tri bander, rotor and Hazer.
I believe that the tower will have to be guyed with the tribander at 40 ft given the wild winds we get here. Tentatively the tower will right next to the back of the house centered on the width of the lot with one guy going to an anchor near the back fence, the other two anchors will be on each corner of the front of the house. I really would like to use pieces of 2 7/8" oilfield tubing about 7 or 8 ft above ground cemented in the ground to keep the guys out of the way.
W8JI addresses in ground guy anchors but I've never seen anything regarding above ground guy anchors. Anyone have any input?
What is the practical limit of a hinged base? I'm thinking of using one so the Hazer can be installed while on the ground, tower raised, the tri bander installed. I like the idea also of having the hinged base as a back up in lowering the antenna should the Hazer become inoperable.
I have an elevated guy point on one of the guy wires on my main tower. It consists of a 12 foot length of "75 pound" railroad rail. Now the 75 pounds is "per yard" (25 pounds per foot) and the anchor weighs 300 pounds. It is 4 feet in concrete. The anchor is in the back corner of my backyard and gets the guy 8 feet above ground at the end.
The late Metz Shatman, WA5KKJ, worked for the railroad and got me the length of rail for free. I know that it "might be" a "bit" of overkill. However, the anchor has been in place for 39 years and it is still going strong! Besides, the price definitely was "right" (FREE)!
A lot of Texas amateur radio operators have used "drill stem" (from oil drilling rigs) successfully for elevated guy points. A piece of damaged "drill stem" can often be had for the asking in oil country.
STH: Any special cementing like a footing or do you just go with a round hole?
Originally Posted by K9STH
I'm familiar with drill stem - a 32 ft joint weighs about 600 lbs, just a tad lighter than railroad rail but I doubt anyone would notice.
I just dug a hole about a foot to 15 inches in diameter, with a clam shell type of "pole digger", put in the rail, and then filled it with "Sackcrete" ("Quickcrete" is the brand that is now available at places like Home Depot). Digging a hole in north Texas "gumbo" soil is not a task for the feint in heart! However, since that same soil has the best conductance in the entire 48 contiguous states, it is a good "trade off".
If it's only 40 feet, why not use a good (Rohn) house bracket, properly installed, the tilt base, and a winch with cable attached to the tower to crank it over? 40' of 25G with a rotator and typical tribander is only about 250 lbs total, not much of a load.
When you have a Hazer and a tower next to the house, you can't lower the beam any lower than the roof, anyway, so it will never come down to the ground.
If you have a good house bracket installed >10' above the ground and well anchored to the house, you probably don't need any guys.
Would a concrete base not work , then it could be free standing ?
You really DON'T want to free stand 40 feet of Ronn 25 even with a pretty small antenna. Having a Hazer and a tri-bander is NOT a small load! House bracketed at about 10 feet above ground and 30 feet above that, a "free standing" Rohn 25 is rated at no more than 3 square feet of load. With no house bracket the rating is even less.
To me, there's a difference between an antenna support and an antenna support I'd want to climb.
I don't want to climb 40' of Rohn 25G that's not guyed. However that doesn't make it unsafe for a small beam.
With a guyed tower, the base is mostly to keep it from sinking into the ground; with an unguyed tower, it's there to hold the tower up! Big difference. Takes a much bigger foundation for an unguyed tower. A pier pin can support a guyed one.
In this instance I'd use about 1-1/2 yards of concrete at the base, plus a house bracket, and that should be okay for 40' if the bracket is at least 10' above ground. I wouldn't use the Hazer except as a last resort. With the Hazer, the load is offset from the center axis of the tower -- by quite a lot. If I used a Hazer for this installation, I'd guy the tower. And the problem is, you can't guy the Hazer itself, you have to guy the tower, and then untie the guys (at the bottom) to bring the Hazer down. That's "work," and should probably only be done on a calm day.
Then, I like climbing towers so I never actually owned a Hazer (although I've installed them for a few people). For me, in the amount of time it takes to disconnect guys and run a Hazer down, I could have strapped on a climbing harness and just gone up there.
A few years back I would have said the same thing about the Hazer vs my climbing the tower but now that climbing is out for me, I suppose it will be my poor man's telescoping tower; I know it's not a telescoping tower but getting the antenna low enough to work on is what counts.
The house is only about 10 ft high at the highest point - flat roof house as far as using the bracket which it does come with.
I'd like to know more about using a winch to crank the tower up and I suppose down the day it needs to be lowered. Years back I saw a few of those but now I don't remember what the detailed set up looked like.