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Why rotate the tower? |
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Although there are many reasons to rotate your tower, the four main reasons are:
1) Less real estate
2) Achieve higher gain and selectable vertical angles on a single band
3) Multiple bands can be covered with single tower and rotor when using directional antennas
4) Ease of maintaining system |
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Is it expensive to rotate the towers? |
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Not really, when you compare the cost of multiple towers or masts and multiple rotors. Rotating a single tower becomes more cost effective because it requires less real estate for multi band
coverage.
Although many costs involved with either a rotating or non-rotating tower are the same, there are quite a
few items that are not required with a rotating tower such as guy brackets and guy arms, long (expensive)
masts, mast thrust bearings and large rotors and rotor cable. With a single rotating tower, it is
possible to mount multiple rotating antennas that operate from 3.5mhz up to dishes for microwave UHF all on
one tower, if desired. |
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How do I install and maintain the tower? |
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One large advantage of rotating the tower is that the installation, maintenance and updating of
antennas is much easier when they are attached to a tower face that can be accessed, versus a long mast
pipe that cannot be climbed. Antenna feed can utilize hard-line all the way from the antenna to the ground
without any jumper cables or splices, making it is possible to bring the hard-line off the tower all the way to
the shack, if desired, thus reducing losses. |
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What is the advantage/disadvantage between ground mounted rotors
and elevated base rotors? |
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The elevated rotor base is an
ideal addition to an existing tower or for use with VHF and UHF arrays. However, lower frequency antennas
require much larger stacking separation so more tower needs to rotate. With the ground mount base, all drive
and control parts are at ground level for ease of maintenance when required. Also as mentioned earlier, any
feed-lines do not need to be broken with flexible cables at the rotation to static part of the system.
Installation of the ground mount rotor is much easier to accomplish. The whole 200 feet of tower can be
installed without having to change sequence part way up the tower. |
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How do I install a ground mount base? |
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Installation of our ground base rotors is very simple, yet effective. Reinforced concrete
should be poured into a four ft. by four ft. hole approximately four ft. deep with rebar prior to
installation. After the concrete has set, the base should be located on top of the concrete pad and eight
holes drilled into the reinforced concrete with a hammer drill. (These drills can usually be rented at most
equipment rental places for a small fee).
After drilling the holes, eight lag bolts are installed
into the holes and tightened down. After the lag bolts are tight, the sections of tower can be installed
upon the base. |
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How do I mount my antenna to the tower? |
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There are a number of opinions about mounting antennas to the legs of a tower.
KØXG manufactures various brackets and plates for this purpose, from two leg mount brackets using 6 U bolt clamps,
to
simple leg to boom plates. We also have a series of brackets to allow booms to be mounted at various angles to the
main tower face. (See our products list.)
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How should I guy my rotating tower? |
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Rotating towers should be guyed with the guy anchors much further out from the tower than
with a regular tower. This will allow antennas with long booms to be installed without any chance of the
elements touching the guy wires. Also, this helps the guy ring bearings turn more easily. We usually
recommend that the guy anchors be installed out from the base of the tower at least the same distance as
the height of the total tower (or even further). This will ensure that even the largest antennas can be stacked
successfully. The distance from the ground up to the guy ring bearings can vary depending upon the antennas
being installed. |
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What rotor cable should I use? |
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We recommend that the motor power feed and control lines be separate. Motor power requires
two conductors and a ground. Romex cable is ideal for the motor power. Control cables should be 6 conductor
20 ga cable, the control leads only draw 80 ma because the main power control is located at the base of the
tower
and control voltage is 24 volts DC. |
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How do you bring the cables off the tower? |
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Coax, hardline, and relay and stack box cables can be installed using our tower swing arm gate.
This will allow the tower to rotate 200 degrees without the cable moving.
Because this arm pivots around a single tower leg, we recommend using two arms - one for feed lines and one for
control cables. Use a large conductor ground cable as a carrier for the other less rugged cables. |
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What do I get when I order a guy ring bearing? |
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All hardware for attaching the inner ring to the tower is included, plus three torque arms to
allow the guy wires to be attached to the ring. |
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What do I get when I order a base rotor? |
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KØXG's base rotor comes complete with everything needed to enable installation of the base and
tower.
A motor control relay box is included at the base with everything pre-wired. All that is required at the box is
motor power, usually 110v AC, also a 6-conductor 20-gauge control wire from the operating position to the base
rotor.
KØXG supplies a number of control box options for the shack depending upon your requirements. |
