Abstract: A rod antenna is contained to be slant in a housing case, such that a top of the rod antenna is positioned on the side of the housing case remote from a user head, and a bottom of the rod antenna is on the side of the housing case near the user head. The remote and near sides are opposite to each other. When the rod antenna is pulled up out of the housing case, the rod antenna top becomes more remote from the user head in accordance with the slantly contained mode.

Abstract: A portable radio provided with a slidable antenna retractably supported by a housing, an antenna operating member movably mounted in the housing for projecting an antenna top portion from the housing by sliding the antenna in a first direction toward the outside of the housing or for releasing the antenna to enable the antenna to slide in a retracting direction opposite to the first direction, and an operating portion for operating the antenna operating member from outside the housing.

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 remote unit for use in a wireless extension telephone system having a self-contained dipole antenna. Utilizing the unique construction of the telephone instrument housing one element of the dipole is included in a planar element that functions normally to direct sound to a self-contained microphone and the other element of the antenna is a static shield used to protect components on printed circuit board included within the extension unit.

Abstract: The central station of a radio-connected seismic surveying system uses a tethered blimp carrying an antenna and an electronics package including a dc voltage/rf decoupler, a variable dc controlled preamplifier, a P-I-N diode switch for changing the antenna from receive to transmit operation, a transmitter and modulator and a battery. An rf coaxial cable to ground provides means for controlling the preamplifier gain and for switching the central station to the transmit mode by using appropriate dc signals. In the receive mode, the cable carries detected field unit seismic signals, which are detected by the blimp-carried antenna and preamplified by the blimp preamplifier, to the ground for suitable recording and further processing in the ground portion of the central station. An audio channel can also be modulated onto the transmit carrier of approximately 70 MHz to provide voice communications via the blimp electronics, if desired.

Abstract: A system for determining the location of the sinking of a vessel by providing a seaworthy box that is automatically ejected from the vessel at the time of sinking and that has a battery aboard the box for powering a radio transmitter that sends distress signals that enable a rescue vessel to locate the ejected box. The system employs a water-activated release mechanism and a stationary box with which the ejected box mates. When the release mechanism operates the box is ejected and at the same time the radio transmission commences. The release mechanism can also be used to release life savers and life boats. The ejected box has a printing system for registering any faults that may have occurred prior to sinking. The vessel may be provided with fire detectors, for example, and operation of a detector is registered along with the time of detector operation to thus provide a chronological log of all important events.