Why is coaxial cable the most common feed line for amateur radio antenna systems?

Coaxial cable is the most popular feed line in amateur radio simply because it is incredibly convenient and forgiving to install. Because the electromagnetic field is entirely contained between the center conductor and the outer shield, coax can be routed alongside metal pipes, taped directly to a tower mast, or even buried underground without severely affecting the signal. Many newcomers incorrectly assume coax is the best performing or cheapest option. In reality, open-wire feed line (often called ladder line) has significantly lower signal loss and can handle much higher power than most coaxial cables. However, ladder line is difficult to work with because it must be kept several inches away from metal objects and the ground. Because coaxial cable does not require these strict standoff distances or special routing considerations, its ease of use makes it the standard choice for most ham radio installations.