A Guide to Coaxial Tecnology

Impedance
There are mainly two impedances used in RF transmission systems. 50
ohm, for higher power signals, such as transmission base stations and
75 ohm for low power signals. 75 ohm offers a lower signal loss than
50 ohm.
It is important to transfer radio frequency energy from a source to a
receiver through the transmission lines with minimum power loss. An
impedance mismatch in a transmission line will cause some of the
signal power reaching the receiver to be reflected back on itself
causing a return loss.
You should never mix 50ohm and 75ohm cables and connectors in the
same system. To achieve optimum results it is best practice to use
cables and connectors of the same impedance.
What is the difference between a 50 ohm and 75 ohm connector ?
The internal materials and structure.
8