Campbell Scientific RF310, RF312, RF313 Narrowband Radios - Manual (Page 32)

Section 3. Radiotelemetry Network Components
3-10
3.3.1 Antenna Mounts
Antennas must be mounted above any surrounding buildings or obstacles.
Antennas must be properly oriented in relationship to the other antennas for RF
communications to work. Antennas have various mounting options. Table 3-7
lists mounting specifications for several common Celwave antennas. Specific
questions regarding antennas can be directed to Campbell Scientific, Inc. or
Celwave. Celwave's address and phone numbers are:
Celwave
Route 79
Marlboro, NJ 07746
(908) 462-1880 or (800) 321-4700
FAX (908) 462-6919
3.3.2 Antenna Orientation
Antennas must be oriented correctly to allow communication between RF sites.
First determine if your antenna is omnidirectional or unidirectional.
An omnidirectional antenna will transmit/ receive in a full 360 degree circle.
Generally, an omnidirectional antenna will be a straight cylindrical rod which is
to be mounted vertically at the top of a tripod.
A unidirectional antenna is designed to transmit/receive in a particular
direction, or in a specified sector. There are various shapes of unidirectional
antennas. The most common is the Yagi antenna (see Figure 1-2). The
elements of a Yagi antenna can be mounted either vertically or horizontally,
corresponding to either vertical or horizontal polarization.
FIGURE 3-4. The PD237 Crossover Plate Antenna Mount
Normally, all antennas will be mounted with vertical polarization. Whichever
polarization is used, be sure to keep antennas at all sites identically polarized.