What is a disadvantage of air core coaxial cable compared to foam or solid dielectric types?

Air core coaxial cable is often chosen for specific applications due to its lightweight and flexibility. However, one of its main disadvantages is its susceptibility to moisture infiltration. Unlike foam or solid dielectric cables, which have insulating materials that help block moisture, air core designs rely solely on the air within them, making them more vulnerable to humidity and water exposure.

If moisture penetrates an air core coaxial cable, it can negatively impact the electrical performance, leading to increased signal loss or failure over time. As a result, special handling and installation techniques must be employed to ensure that the cable is protected from moisture, such as using weather-tight fittings and keeping connections elevated.

On the other hand, foam and solid dielectric cables have superior moisture resistance due to their insulating properties, making them more reliable in wet or humid environments. Thus, the need for special techniques to prevent moisture-related issues is a significant drawback for air core coaxial cables as compared to their foam or solid dielectric counterparts.