Large Dish Installation Guide
Pouring The Pad
IF you elect to proceed with the installation of a large aperture antenna
yourself, you will need to construct a foundation for the mount. In the case of a
pole-mount antenna, a steel pipe is placed in a hole in the ground and
embedded in concrete, Because it will take a few hours for the concrete to
harden, it is a good idea to set the pole the day before you construct the
antenna. You also can buy quick drying concrete products which will set up in
less than an hour. Be sure to use a level to ensure that the pipe is “plumb”
before the concrete sets. Other types of dish mounts will requite a concrete
pad for the foundation. Concrete piers extending well below any frost line
should be incorporated into the pad design. Certain types of antenna mounts
merely need a level surface. Detailed instructions are supplied by the dish
manufacturer.
For rooftop installations, the roof structure must be able to support the weight
of the dish, as well as withstand the uplift forces of several thousand kilograms
resulting from moderate and high speed winds. After all, nobody wants the roof
torn off and the dish flung through the sky.
Because roof top installations are more susceptible to microwave interference
than those on the ground, a site survey with a spectrum analyzer or an on-site
rooftop demonstration with a small potable dish is an absolute necessity in any
country where microwave interference is a major potential problem. If several
of your neighbors have antennas, you can check with them to see if they
experiencing any interference problems.
Mount Alignment
The pivotal axis of a polar mount antenna must be accurately aligned to true
north. Even when this alignment is done with an engineer’s transit, slight
inaccuracies in the measurement may result, causing uneven tracking of the
geostationary satellites. Corrected compass readings may be even further off
the mark. While compass readings may be useful during the site survey for
locating a clear view of the satellites, the real test of your polar mount’s
alignment is the video reception which you obtain.
When mounting the antenna onto the pole, tighten the bolts just enough to
hold the antenna in place. Tightening the bolts down firmly on the pole should
be one of the very last things you do, and should be one of the very last things
you do, and should be done only after you have gotten the dish to track the
Kiwi Antennas Limited
www.kiwiantennas.co.nz
