Abstract: A selective call receiver (100) comprises a battery powered receiver (104) for receiving and presenting a message, a battery having terminals for electrical coupling thereto, and a housing (208) enclosing the receiver (104) and the battery. The housing (208) has a first opening (206) for receiving the battery and at least one second opening (234) separate from the first opening (206) for securing a battery door (FIG. 4). The battery door (FIG. 4) provides access to the battery contained within the housing (208). The battery door (FIG. 4) comprises a hinged member (214) having a first end (238) coupled to the housing (208) for rotating between a closed position and an opened position, and a second end reduced to form a tongue (240).

Abstract: A negative glow discharge lamp having improved efficacy enabled by reducing the anode work function by the introduction of a metal-based gas into the lamp envelope for absorption on the anode. The metal-based gas is preferably cesium but may also, for example, be sodium.

Abstract: The disclosure relates to a microprocessor based telemetry apparatus and method utilizing a commercially available IBM PC-AT or compatible CPU. Three hardware cards fit in existing slots within the computer chassis. Software is provided to accomplish, in combination with the cards, what has essentially required a mainframe computer heretofore. The microcomputer is equipped with novel hardware and software to provide PCM bit synchronizer/decoder, decommutator, time code reader and digital-to-analog converter functions. Data is stored in real time using interleaved buffers, novel software and a hard disk. Data can be archived on digital tape. Data logging can be carried out at sustained rates approaching 2 million bits per second, up to six times faster than with MS-DOS yet files are accessible with MS-DOS. Real-time data scaling and display of up to 128 separate parameters are accomplished.

Abstract: An electron tube with concentric, cylindrical electrodes has at least one meshed type of grid, a mesh being defined by several rods in contact by their ends, each point of contact forming a node. In order to limit the grid current, the surface area of a node is reduced. Only three rods leave each node. The meshes are hexagonal.

Abstract: Apparatus for interfacing a network manager to a network of communication devices over a single communications channel of a plurality of signals is disclosed. Each communication device of the network is uniquely assigned a poll address for communication selection by the network manager which is operative to establish communication with a communication device of the network by transmitting the poll address thereof over the single communication channel. The network of communication devices are coupleable together in a daisy chain through input and output port circuits thereof to form the single communications channel. The input port circuit of each communications device receives and transmits signals from and to the single communications channel upstream of its position in the daisy chain and the output port circuit of each receives and transmits signals from and to the single communications channel downstream of its position in the daisy chain.