Campbell Scientific RF310, RF312, RF313 Narrowband Radios - Manual (Page 33)

Section 3. Radiotelemetry Network Components
3-11
3.3.3 Antenna Cables and Connectors
The most common cable type to connect a radio to the antenna is a coaxial RG-
8A/U cable. Two connectors are required for each length of cable. The
connector for the radio is a BNC type connector. The connector for the antenna
is usually either a Type-NM or Type-NF. The BNC, Type-NM, and Type-NF
connectors are shown in Figure 3-6. The Type-NM (male) connector is for
antennas with a female receptacle, and Type-NF (female) for antennas with
male receptacles.
A Campbell Scientific antenna cable complete with connectors is specified as
either COAX NM-L or COAX NF-L. COAX NF-L is a coaxial RG-8A/U
cable with a BNC connector on one end and a Type-NF connector on the other.
See Table 3-5 for cable requirements for common antennas.
Due to power loss through the cable, the length of coax cable cannot be
extended to any desired length. The amount of power loss is dependent on the
radio frequency. RG-8A/U will lose approximately 3.1 dB/100 ft. at 200 MHz
and 5.0 dB/100 ft. at 400 MHz. Power loss calculations are reviewed in
Appendix C.
FIGURE 3-5. The PD46 Clamp Mount
FIGURE 3-6. Type-NM (male), BNC, and Type-NF (female) Connectors