Coaxial HF cable e.g. for TV broadcast programs

A coaxial HF cable has a dielectric between inner and outer conductors which contains components to reduce energy loss that are based upon polyisobutylene. The components form a predominant part of the intermediate layer directly surrounding the inner conductor, this having a thickness of between twenty and two hundred microns, but preferably between fifty and a hundred. The proportion of the components is from 50% to 90%. The viscosity of the components lie between 10 power 2 and 10 power 9 Pa.s (Pascal- seconds), but preferably between 10 power 4 and 10 power 8. The thermal content of the intermediate layer serves to compensate for the pores in the dielectric foam.