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Antenna Mast Guying for
Simple Ham Radio Antenna Installations This article will explain the proper guying heights and guy lengths
when guying ham radio antenna masts. It will help you determine ahead of
time the proper length of guy wires and the distance from the base of the
mast to the anchor points. All of the information contained within the
article is based on Rohn engineering specifications for their H series
telescoping masts. All masts represented in this article are in 10 foot
telescoping sections and Rohn recommends guying every 10 feet. Distances
from the antenna mast base to anchor points are shown and suggested
lengths of guy wires from anchor point to mast guy point. You will need to
make each longer for securing them on both ends.
Do not use any information in any part of this
article for guying towers!
See drawings below.
20 Foot Mast Recommended guying
above
30 Foot Mast Recommended guying
above
40 Foot Mast Recommended guying above
Notes and
disclaimers:
This article only recommends lengths and heights of guy
wires and guy points and does not recommend any particular hardware for
attaching guys to mast, hardware, or the type of anchors. Refer to
the Rohn specification links below for more detail.
Rohn Telescoping Masts and instructions: Pdf Download
Also see How To Find Unknown Guy Wire Lengths
when you know height of tower or mast
and distance to the guy anchor! Uses some simple math to determine the
unknown guy length.
NEVER
install a mast near AC power lines. All
points of the installation including guy wires MUST be a safe
distance from power lines if any part of the installation falls or fails.
Note that if a guy wire breaks under stress or if the mast falls, it will
usually fly back or land in the direction of "Murpheys Law".
If
it can't happen, it will! Be SAFE ahead of time! Don't do it by yourself,
get plenty of help! Watch those electric power lines. A good rule of thumb
is to have at least 1 1/2 times (or more) of the mast height from its base
to the nearest power line...if your not sure, add more! Remember, when a
guy wire breaks under stress, it may act like a sling shot and may
land on power lines!
Note that there are 2 methods of attaching guy points recommended
by Rohn - 3 guys at 120 degrees apart and 4 guys at 90 degrees apart.
Refer to drawings above.
You may use either one but the "4 guy" method
would be the strongest.
Antenna load (top load) should not exceed an effective
projected area (EPA) of 2 square feet for this type of mast (see your
antenna specifications).
The drawings in this article are based
on Rohn H Series Masts.
This heavy duty series of Telescoping Masts
uses 1-1/4" 16 gauge galvanized tubing for top section.
All other
sections are 18 gauge.
It is always better to "over guy" rather
than skimp to save money. A penny saved may not be the best idea when you
have to put it all back up!
After it falls, it is too late to say "I
wish I had put it up the right way"!
This article is NOT intended as an installation guide for
installing any antenna mast.
It should only be used for determining
the lengths needed for guy wires and their suggested guy points for Rohn H
series masts or equivalent. If you use your own homebrew mast, use every
safety precaution and over design it.
We assume no responsibility for
your installation.
Graphics and other portions of this article
copyrighted by Rohn Products LLC.
?2009 ROHN PRODUCTS
LLC
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