Abstract: A television transmission system for transmitting UHF signals from a UHF signal generator, the system comprising an antenna for radiating UHF signals generated by said UHF signal generator, an overmoded section of waveguide for carrying the signals at least part of the way between the UHF signal generator and the antenna with a low level of power loss, and a high-power mode filter coupled between the antenna and the overmoded section of waveguide.

Abstract: A rigid coaxial transmission line in which the inner conductor is formed by axially spaced sections. Adjacent sections are connected by a conductive bellows which permits thermal expansion and contraction of the inner conductor sections relative to one another and relative to the outer conductor of the transmission line. A rigid auxiliary connecting member is disposed within the bellows and is slidably connected to one of the conductor sections. The auxiliary connecting member limits expansion and contraction of the bellows to a safe range to prevent the bellows from being overstressed.