Over the years, various manufacturers have made different recommendations for the installation of rigid coax line. The following procedure is what we feel is the best.

Rigid transmission line should be stacked from the bottom up, after the horizontal run has been determined to be free of tower obstructions to allow for expansion. Two fixed hangers should be placed in the lower sections at the start of the vertical run (to be removed later). The placement of these fixed hangers prior to stacking the line is important. If the line was being installed in the middle of the average operating temperature, the horizontal run would be absolutely level. Tower clearances have to be considered when there are temperature extremes at the time of installation. Normally, rigid coax requires about eight (8) inches (+ or -) expansion room from center line of the horizontal run at average temperature. The lines should then be stacked on the tower one at a time and, for speed of assembly, can be temporarily bolted with every other bolt. The pressure plates provided with each system should be at hand in case of a change in weather conditions. The vertical spring hangers should be completely aligned prior to stacking any vetical run.

When stacking the line from the bottom up, the weight of the line tiself helps compress the "O" -ring below it. It allows for more accurate torque on the bolts during assembly and allows the installer to pressure check the sections of line he has assembled during that day. At the end of each assembly day, the stacked line should be charged with nitrogen. The pressure should be checked the following day prior to further assembly. It is important that this be done immediately so the line is not subject to any undue stress. All pressure checks and electrical tests should be completed before the tower is unrigged and the rigger is dismissed.

Please consult S.W.R.'s chart on page 17 for placement of the first vertical hanger.

We feel that S.W.R. manufactures the best transmission line available, but the care and planning of the installation will determine the quality and length of its performance.