Abstract: A nonsquinting end-fed quadrifilar helical antenna is provided. Each conductor of the antenna is fed with a successively delayed phase representation of the input signal to optimize transmission characteristics. Each of the conductors is separated into a number Z of discrete conductor portions by Z-1 capacitive discontinuities. The addition of the capacitive discontinuities results in the formation of an antenna array. The end result of the antenna array is a quadrifilar helical antenna which is nonsquinting (radiates in a given direction independently of frequency).

Abstract: Lighting devices for an aerostat tether wherein the tether is used as a communication antenna. The lighting apparatus includes a split core transformer having a plurality of turns of secondary winding with the electrical portion of the tether constituting a single turn primary. The secondary voltage is provided to a voltage limiter which reflects excess energy back into the primary circuit, with the output of the voltage limiter being fullwave rectified and regulated to a predetermined DC value for operating a strobe light.

Abstract: A VLF communication system which utilizes the tether of an aerostat system as the VLF antenna. The aerostat is flown at an altitude such that the tether is approximately a quarter wavelength of the operating frequency and the transmitter signal is coupled to the antenna by means of a elongated sleeve transformer surrounding the tether and including a single turn primary coupled to the transmitter with the tether acting as a single turn secondary of the transformer.

Abstract: An improved tether having a central strength member comprised of layers of synthetic fibers surrounded by a thin weatherproof plastic barrier. A current carrying metallic braid surrounds the weatherproof barrier and in a portion of the tether is of a higher strength and denser weave copper than in other areas. An outer protective jacket surrounds the metallic braid and one or more windows are formed by removing a short longitudinal section of the outer jacket above an area of the tether which has the high density metallic braid. The weatherproof barrier, at least in the area where windows are formed, is heat sealed to form a seamless barrier. A relatively soft copper wire is wound around the metallic braid in the window area so as to transfer lightning induced currents in the metallic braid of the tether to a grounding system.

Abstract: The aerostat-supported antenna/tether cable of a communication system is protected from destructive corona discharges by a dual corona ring assembly which attaches the feed cable of the transmitter to the antenna. The voltage divider assembly includes upper and lower corona rings which have a space between them which is an isolated and corona-free attachment point for the feed cable. By attaching the voltage divider assembly to the antenna/tether cable at about 12 to 15 feet above the ground, the base of the antenna/tether cable distributes the feed voltage along its length to levels below those voltage levels in which destructive ionization may occur.

Abstract: A VLF communication system which utilizes the electrically conducting portions of an electromechanical cable connected to a deployed aerostat and acting as its tether so as to additionally serve as the VLF antenna.

Abstract: A flexible strap-like antenna which may be supported on the outside surface of an aerostat includes a first substrate member having conductors thereon in a pattern which includes a center conductor and dipole antennas on either side of the center conductor. A ground conductor is disposed over the center conductor and is electrically insulated from it by an insulating strip sandwiched between them. A second or covering substrate seals the layered arrangement.To achieve broad band operation, an array of antennas is provided with the width of the center conductor being varied for certain different sections thereof.

Abstract: An improved antenna of a coaxial type utilizing Z-shaped slots disposed in the outer conductor to provide an omnidirectional antenna pattern. Current coupling to the slots is achieved by means of the transverse portion of the Z slot. Detuning effects due to the presence of a transmission line are compensated for by dielectrically loading the slots with a dielectric cover over the coaxial line and/or by lengthening the longitudinal arms of the Z. The longitudinal spacing between each slot and the length of the transverse portion of each slot are chosen while considering all line effects to obtain the required phase and amplitude relationships. The antenna consequently requires no additional coupling, tuning or phasing devices mounted within or without the coaxial line.