Radio Towers: Frequently Asked Questions
If you’ve never dealt with a radio tower before, here are some typical questions and answers.
NOTE: A more thorough discussion of each topic is included in the book “ UP THE TOWER – The Complete Guide To Tower Construction.”
1. What is a tower?
A tower is a typically steel structure used for safely supporting some sort of antenna or camera; e.g. WISP, WLAN, public service, amateur radio, broadcast, etc.
2. What kind of towers are there?
Towers come in two flavors – self-supporting (or free-standing) or guyed.
3. Which one is better?
Self-supporting towers require less real estate. A 100’ self-supporting tower base can be as little as 6’ x 6’. A guyed tower needs guy anchors 80% of the height away from the tower so a 100’ guyed tower needs 3 anchors 80 feet away from the tower, an area 0.6 of an acre and a footprint 170’ square.
They both get you the same thing – height – but the guyed tower is a little cheaper since the inexpensive guy wire replaces a lot of the steel needed for a self-supporting tower.
4. How much height do I need?
Chances are that your requirement is line-of-sight so you’ll need to be able to see from one end of your path to the other. That means you’ll need to clear trees, buildings and other obstructions. If you can’t easily get high enough to visually check out your path, one quick way to do it is to rent a crane with a man-basket or other kind of power lift and actually get up to the desired height. There are path analysis websites on the internet as well.
5. What do I need to know in order to specify a tower?
The two basic parameters are local windspeed conditions and proposed windload. You can get the windspeed from your local building department or look it up at http://www.championradio.com/windspeed.php although your building department windspeed may be higher due to local requirements. The windload is the sum of the square footage area of the proposed antennas; the square footage is available from the manufacturer.
6. Will I need a building permit?
Probably. Check with your building department for more info. As part of your building permit application package you’ll probably need a set of stamped PE (Professional Engineer) plans. These can run from $500 to $1000 or more.
7. How do I get it built?
You can get a local concrete contractor to install the base and anchors if needed but you’ll need a qualified tower crew to install the tower and antennas. They’re around and may not be local to your area but you might have to do a little detective work to find them.
8. What’s it going to cost?
For a typical tower less than 100’, the whole thing can cost between $5-10,000 including the tower. The major costs are the tower itself, the concrete and labor.