R. F. POWER RATINGS OF TEFLON COAXIAL CABLES

Abstract : The increased power handling capacity of the Teflon cables over the equivalent polyethylene cables is clearly demonstrated. Excluding the Teflon tape cable construction for the moment, the sizable increase in power handling performance of Teflon over polyethylene would certainly warrant its use wherever possible. Where a large diameter polyethylene cable is being used, a small diameter Teflon cable could be substituted with the advantage of weight reduction, increased maximum power capacity and a higher maximum operating temperature. For instance, from a power handling viewpoint, RG-87A/U cable could easily be used where RG-17/U is now used. RG-17/U handles 4500 watts at 100 megacycles while RG-87A/U handles 6500 watts. At 4000 megacycles, RG-17/U handles 350 watts and RG-87A/U handles 750 watts. Therefore, RG-87A/U, if substituted for RG-17/U, would not have to be operated at its maximum rating to equal and outperform RG-17/U. One might even wish to use RG-115/U in place of RG-17/U. At 100 megacycles, the power ratings of both cables are quite close while at 4000 megacycles, RG-115/U can carry 450 watts and RG-17/U carries 350 watts. In addition, RG-115/U has the advantage of greater flexibility and improved temperature dimensional stability as compared to RG-87A/U. Where high temperatures will be encountered due to high power requirements, and compactness and weight are significant factors, the Project Engineer will certainly do well to investigate the utilization of a Teflon dielectric coaxial cable. (Author)