Campbell Scientific RF320-Series Ritron VHF/UHF Radios - Manual (Page 19)

RF320-Series Ritron VHF/UHF Radios
o Connectors
- All exposed RF connectors should be weatherproofed. A good
method is to apply overlapping wraps of a good quality mastic
tape, extending several inches beyond either side of the
connection, then cover the mastic tape with tight, overlapping
wraps of a good quality vinyl tape.
- Maintain electrical connectors in a clean, corrosion free condition
by means of a periodic application of a good quality aerosol
based contact cleaner.
• Radio Placement
o Minimize Electromagnetic Interference (EMI) by not locating the
radio in close proximity to EMI sources such as other radios, video
equipment, AC motors, computers, and lighting ballast.
• Antenna
o Polarization
- One characteristic of an antenna (more precisely, the
electromagnetic wave emitted by the antenna) is polarization.
Polarization is defined by the orientation of the electric field of
the EM wave with respect to the surface of the earth. A vertical
dipole antenna is vertically polarized. The polarization of a Yagi
antenna is determined by the orientation of the radiating elements.
To match the vertical polarization of the dipole antenna, the Yagi
must be mounted so that the radiating elements are vertical
(perpendicular to the earth’s surface). Failure to match the
polarization of the antennas will lead to significant signal loss.
o Elevation
- In general, the greater the antenna elevation above the local
terrain, the better the RF signal propagation. The trade-off is
increased cable loss and higher installation cost.
o Placement
- Locate the antenna in an area that provides an unobstructed line-
of-sight to remote sites.
- If using a directional antenna, mount it in a manner that allows
for properly aiming the antenna in both azimuth and elevation,
and maintains the alignment when subjected to the loading forces
of wind, snow, and ice.
- Mount the antenna to a mechanically-sound structure in a location
that will protect it from damage but will allow safe access for
maintenance.
- Avoid locating the antenna in close proximity to other antennas,
utility lines, or other sources of signal noise.
o Lightning Protection
- Antennas, by nature, are susceptible to lightning strikes. It is
strongly recommended that in-line surge protection be utilized.
Campbell Scientific offers the Antenna Surge Protection Kit
(CSI# 16980) for this purpose.
7. Operation
The RF320-series radios operate over a range of synthesized, narrowband
channels in the VHF and UHF spectrum. The RF320 operates in the VHF band
(136 to 174 MHz), while the RF321/322/323 operates in the UHF band (400.5
to 416.0, 411 to 429, and 450 to 470 MHz respectively). The radio can be
programmed with up to eight selectable operating channels, each with
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