Abstract: A radar transmitter apparatus comprising a radar transmitter equipped with a modulator arranged in an oil-filled housing, the modulator being held in spaced relationship with respect to the inner walls of the housing in order to form an intermediate space for the convection flow of the oil. The housing is substantially trough or vat-shaped and covered by a trough or vat-shaped cover member. In the internal chamber or space between the cover member and the modulator, which internal space is wetted by the oil, there is arranged, on the one hand, a magnetron attached at the cover member and, on the other hand, a thyratron which is mounted directly below an opening at the cover member. This opening is closable by means of oil sealed throughpassage means.

Abstract: A location transmitting system for use by one or more guards in a security system. Encoders are located at predetermined reporting locations which have no power supplies. Each guard carries a walkie-talkie radio transmitter which he places in a receptacle at the reporting location, energizing the encoder through external terminals in the receptacle which mate with external terminals of the walkie-talkie and its power supply.

Abstract: A system for opening garage doors in which a radio receiver in the garage, upon receipt of a signal, operates to open the garage door and in which a casing containing a radio transmitter is adapted for insertion into the socket of a cigarette lighter in the driver's compartment of a motor car. Switch means are provided for connecting this transmitter with a source of electrical power to actuate the transmitter and emit a radio signal at a frequency to which the receiver is receptive when the casing is inserted into the socket. The invention also contemplates a radio transmitting device in which a casing containing a radio transmitter is insertable into a socket of any type at any location together with means for energizing the transmitter to emit a signal when the casing has been inserted in the socket, for whatever purpose the signal may be utilized.

Abstract: An electrical apparatus is provided with a cabinet which accommodates an electrical device having a control member and a box-shaped member both projecting beyond the circumference of the cabinet. The open control side of the apparatus is closed by means of a reversible front plate which fits over the control member and the box-shaped member. The front plate has a peripheral endless upright wall which renders the apparatus suitable for building into a wall or, upon inverting of the front plate, for mounting against a wall.

Abstract: A portable transceiver includes a two-piece transceiver housing which encloses a double-sided printed circuit board. The transceiver housing includes a front surface portion and a control panel portion which is integral with, but recessed below, the front surface portion. Within the control panel portion are four clearance apertures which provide operator access to the operator controls of the printed circuit board. The width and depth of the housing are suitably sized to enable the portable transceiver to be hand held in one hand while the thumb of that same hand is able to manipulate the various operator controls. These controls protrude through the various clearance apertures yet the outermost portions of the controls remain flush with to recessed below the front surface portion. The printed circuit board is a self-contained transceiver such that all wiring is completed prior to installing the printed circuit board into the transceiver housing.