What is a common issue with antenna cables that requires replacement?

Exposed wire braid is a significant issue with antenna cables that often necessitates replacement. The braid typically serves as a shield to protect signal integrity and prevent interference. When the wire braid is exposed, it can lead to several problems, including increased susceptibility to electromagnetic interference and potential short-circuiting with surrounding components. This exposure can degrade the quality of the signal being transmitted or received, leading to poor performance of the avionics system. Ensuring that the cable is intact and that the shielding is properly secured is crucial for maintaining operational reliability and minimizing signal loss in aircraft systems.

The other options, while they may indicate potential issues, do not directly influence the safety or functionality of the cable to the same extent as exposed wire braid does. Excessive length can lead to signal loss but does not necessarily require replacement if managed properly. Unusual insulation color may indicate a non-standard cable but does not imply a functional problem, and old connectors might be replaced if they show signs of wear but do not directly affect the cable integrity like exposed braids can.