A communications system and network wherein communications links between subscribers are established by retrodirective oscillating loops between each subscriber and a node station. Provision is also made for establishment of links between nodes so that remotely located subscribers can communicate. Information is transmitted between subscribers by using a mixing process in the node whereby information transmitted from one subscriber to the node is transferred at the node to a carrier signal trans...

A solid state network for subscriber stations which uses a first active element to couple both the transmitter and the receiver to the telephone lines and uses non-inductive component for compensation to minimize costly heavy components and to facilitate transmission and reception of communication signals almost independently of variations in line length.

A network of different weighted resistances, for example, binary resistances, coupled in parallel with each other, is provided in a semiconductor body by providing a plurality of substantially identical resistors, with different numbers of the identical resistors being coupled in parallel to provide the required different weighted resistances of the network, possibly, the constituent identical resistors of the different weighted resistances of the network being interdigitated with each other. Th...

An electronic circuit, for connecting a transmitter and receiver to a telephone line. The circuit operates on very low operating voltages from the line which allows parallel operation with a conventional set on long-loop applications. In its functional form, the circuit utilizes a bridge configuration having transistors in two of its legs, driven by the transmitter output, thereby eliminating the usual bridge balancing resistors therefrom and their concomitant operating voltage drops thereacross...

A network computer system in which the individual processors are arranged in the form of a matrix, with each processor connected with its directly neighboring processors. The individual processors are checkerboard-like assigned to one of two groups, and each group is connected, by its own instruction line, to a control unit for connection to the control computer. The system is useful in performing iterative calculations in which the processors of the one group calculate new values on the basis o...

An antenna matching network for matching a citizens band radio transceiver to a standard automotive whip or windshield antenna utilizes a matching section for matching the nominal 50 ohm output of the citizens band transceiver to the generally lower impedance of the automotive antenna. A trap tuned to the citizens band prevents the output of the citizens band transmitter from damaging the automotive broadcast receiver when transmitting. The matching section is tunable over a sufficient range to ...

A corrective network for obtaining a desired overall frequency response comprises a plurality of tunable, non-active resonant circuit stages, each connected with a source and operative for modifying the frequency response over a respective portion of the frequency spectrum. Each resonant stage comprises a variable differential capacitor having a rotor plate terminal and two stator plate terminals. Each stage further includes a series circuit branch constituted of a resistor and an inductor which...

A phase tracking network comprising a phase correction network for correcting at least some of the phase error of an input signal to provide a phase corrected signal having components in first and second channels and a detector responsive to the phase corrected signal for providing a detected signal having first and second components in the first and second channels. An error calculator provides a phase correction signal back to the phase correction apparatus which responds to the phase correcti...

A radar antenna includes a plurality of radiators disposed near the focal point of a parabolic reflecting surface. The radiators are coupled to a sector horn waveguide via a plurality of phase shifters and a Butler matrix. The sector horn is concurrently excited in H.sub.10 and H.sub.12 modes of propagation to provide excitation to the radiators. Radiated energy from a radiator propagates to the reflecting surface and is reflected therefrom.

A sludge digester is equipped with a network of pipes leading to several separate effluent ports distributed around the base of the digester near its walls. During use, sludge undergoing active digestion within the digester is withdrawn from the digester and forcefully pumped through at least one of said pipes to flush or sweep material tending to settle from less active regions of the digester into other regions undergoing active digestion, thus to prevent accumulations of sludge which is not a...