Microwave Pipes (Jul, 1955)

Long-Distance Microwave Pipe Carries Many Television Programs

Tens of thousands of cross-country telephone calls along with hundreds of television programs may someday be carried in a single two-inch metal tube. The longdistance wave guide, developed by Bell, could be buried underground and would funnel extremely short microwaves up hill, down dale and around corners. It is constructed of thin copper wire, tightly
coiled like a spring under pressure and wrapped inside a flexible outer coating which holds the wire in place. In laboratory tests, microwaves have been carried for 40 miles in a metal tube with the same loss of strength encountered when the waves travel 12 miles in a coaxial cable. The system uses microwaves shorter than any previously used in communications.