What is the most common cause for failure of coaxial cables?

Moisture contamination is indeed the most common cause for failure of coaxial cables. Coaxial cables are designed to be used in various environments, but when moisture seeps into the cable, it can lead to several issues. Moisture can degrade the insulator material, leading to short circuits, corrosion, and excessive loss of signal quality. This is particularly problematic in outdoor installations where water exposure is more likely.

Before moisture can cause these failures, good installation practices and weatherproofing techniques are essential to protect the cable. Ensuring that coaxial connectors are properly sealed and using dielectrics that resist moisture can help mitigate this issue. Other environmental factors like UV exposure or physical damage from chemicals can also contribute to cable failures, but moisture is the most prevalent cause.

In contrast, while gamma rays can affect sensitive electronic components, they do not typically cause failure in coaxial cables. The velocity factor exceeding 1.0 does not occur as coaxial cables are designed with a specific velocity factor that reflects the speed of the signal. Lastly, overloading can lead to equipment damage rather than cable failure, as coaxial cables are rated to handle specific power levels safely, so long as those limits are adhered to during use.