chapter  2
10 Connectors
Pages 1

Parallel tubing (air dielectric) 0.95

Coaxial line (air dielectric) 0.85

Coaxial line (solid plastic



Two-wire line (wire with plastic


0.68 to 0.82

Twisted-pair line (rubber


0.56 to 0.65

Table 2.3 Velocity factor for various types of feeder

Figure 2.40 Coaxial connectors (from left to right: PL-259, BNC, and N-type)

Figure 2.41 Method of fitting a BNC-type connector to a coaxial cable

Connectors provide a means of linking coaxial

cables to transmitting/receiving equipment and

antennas. Connectors should be reliable, easy to

mate, and sealed to prevent the ingress of

moisture and other fluids. They should also be

designed to minimise contact resistance and,

ideally, they should exhibit a constant impedance

which accurately matches that of the system in

which they are used (normally 50 Ω for aircraft