Why is having a low SWR important in a coaxial cable feedline?

Having a low SWR (Standing Wave Ratio) is important in a coaxial cable feedline primarily because it allows for efficient transfer of power and reduces losses. When the SWR is low, this indicates that most of the power transmitted from the transmitter is being effectively delivered to the antenna without being reflected back into the coaxial cable. High SWR means that a significant amount of power is reflected back, which can lead to wasted energy.

Additionally, with low SWR, the cable experiences less heating and strain, which can prolong the lifespan of both the feedline and the antenna. While other factors, such as reducing television interference, may also play a role in the overall performance and environmental impact of the setup, the fundamental reason for maintaining a low SWR is the efficiency of power transfer.