For proper performance, the impedance of the cable should match the impedance of the antenna input on the receiver (50 Ohms for Shure receivers). An impedance mismatch causes some of the signal to be reflected back into the cable, resulting in a reduction of signal level ...For proper performance, the impedance of the cable should match the impedance of the antenna input on the receiver (50 Ohms for Shure receivers). An impedance mismatch causes some of the signal to be reflected back into the cable, resulting in a reduction of signal level.
Different types of cable are rated according to the amount of signal loss over a specified length (usually 100 feet). These ratings are specific to the frequency range of the signal being passed (VHF or UHF). The maximum length of cable is dictated by how much the antenna amplifier can boost the signal.
Antennas should be mounted away from large metal objects or surfaces, which cause reflections that can reduce signal strength. Antennas should also be kept away from sources of RF energy, such as computers, digital devices, AC power equipment, etc.