Coaxial Cable (Ulearn Network Technician Core Skills) Flashcards
All coaxial cables will consist of
center conductor, dielectric, foil/braid, jacket
Two types of leakage
Egress and Ingress
Coax carries both
RF and AC
Underground coax contains a _______________ between the outer conductor and the protective covering
Flooding compound
What component of coax cable is responsible for keeping the two conductors separate?
Dielectric
Over-the-air signals entering the cable network through shielding defects such as loose connectors, cracked cable, un-terminated tap ports, etc.
Ingress
Undesired emission of RF signals from the HFC network, which is sometimes called signal leakage
Egress
CLI
cumulative leakage index
Signal leakage limits between 54 MHz and 216 MHz
20 μV/m at a distance of 10 Ft. / 3 m
Signal leakage limits at 0 to 54 MHz and above 216 MHz
15 μV/m at a distance of 100 Ft. / 30.48 m
The characteristic impedance of the coaxial cable in cable telecommunications networks
75 ohms
Three things that determine the characteristic impedance of coaxial cable
The inner diameter of the outer conductor, The outer diameter of the center conductor, Type of dielectric material
The difference between the transmitted power and the reflected power in dBs
Return loss
Most coaxial and HFC systems aim for return loss (RL) greater than or equal to
16 to 18 dB
RL
Return loss
