41
Installing the Antenna
Description, Specifications, and Installation Manual
Installing the Omni Fiberglass Antenna Models
NOTE
: No tuning is required for this model.
“Figure 9 Omni Antenna Installation Example” on page 42.
To install the Omni antenna, do the following:
1. Install antenna, (using installation bracket or equivalent) as high as possible, such
that the antenna cable and obstacles allows, and install on side of pole closest to the
receiving station.
Install a service loop when routing antenna cable.
NOTE
: Objects around the antenna affect the antenna, keep antenna away from
objects, and at least ¼ wavelength from siren pole.
(λ = C/f, where C = 1.18 x 10
10
in/sec)
2. Ensure antenna cable connections are tight. Seal all connection points with heat
shrink or tape and seal with Scotch Coat, or equivalent.
3. Apply RF power to the antenna at the transmit frequency to be used at that antenna,
and check the VSWR (Reflected power). Reflected power must be less than 10% of
the forward power.
If the VSWR specification is unattainable, replace the cable (A simple ohm meter
check of the cable does not guarantee that the antenna cable is good, due to the
DMM not having the ability to check the cable at high frequencies). If that does not
take care of the problem, replace the antenna.
Figure 8 Yagi Antenna Installation Example
