A multichannel telegraphy receiver for harmonic telegraphy where for each channel different levels of an input signal are characterized by different frequencies of the carrier. The receiver comprises for each receiver channel a discriminator including a digital counter, a continuously active counting pulse generator coupled to the input of the counter and a decoder connected to the counter and having an output circuit formed by a register. The register has a separate output for each of the diffe...

1. Apparatus for producing multiple combinations of parallel output binary signals for controlling an anti-jam or other form of telegraphy system comprising four parallel feedback shift registers, a pair of serial to parallel converters, each having an input terminal, means for combining the output signals of said shift registers for producing two separate serial signals, means for coupling one of said serial signals to the input terminal of one of said converters, means for coupling the other o...

An electronic transmitter for direct current telegraphy systems. In order to limit cross-talk between neighboring telegraph lines it is known to filter telegraph signals prior to transmission to "round-off" their edges. In the present electronic transmitter telegraph signals are given approximately "sinusoidal edges" by the use of a function generator. In FIG. 1 an electronic transmitter comprises an input circuit 1, a switching circuit 2 and an output circuit 3. Binary information signals at an...

A combined telephone-telegraphy system is disclosed herein and which includes a plurality of local calling boxes and central station communication equipment connected together in a series circuit. Each local calling box includes telephone equipment for transmitting and receiving voice frequency signals to and from the central station equipment, as well as telegraphy means for transmitting coded box, identifying tone frequency signals to the central station equipment. Each local calling box also ...

An electronic transmitter for direct current telegraphy by means of polar line currents has a switching circuit that selectively connects one of the two poles of a telegraphy battery through a unipolar constant current source to a telegraph line, and an output filter having a capacitor in parallel with the telegraph line. The higher frequencies in the telegraphy signals are sufficiently suppressed to keep the noise level in adjacent telephone lines below a prescribed value because the output fil...

Satellite communication system for speech signals located within the telephony band and one or more data signals, wherein half-duplex data traffic between ground-based stations can be effected simultaneously with, but separated from, full-duplex speech traffic between two ground-based stations. The use of a second receiver enables all ground-based stations to follow both the data traffic and the speech traffic.

A vibration transducer, comprising a conductive member, such as a weighted carbon bar loosely fitting into support means, such as a pair of carbon bearing blocks with the bearing blocks rigidly attached to a flexible membrane, serves as the transmitter of the voice transmission system. The bearing blocks are series wired into an electrical circuit, including a direct-current power source and a loud-speaker coil. A fluctuating pressure signal sets the flexible membrane into vibration and causes t...

A system for the automatic establishment of a shortwave telegraphy signal connection between two transmitter-receiver stations within a frequency range subdivided into several channels. Both stations use their receiver to determine objective measurement values reflecting the transmission conditions over the individual channels. Active and passive channel analysis of the actual quality of the signal transmission is determined at each channel. The transmitter of the calling station is automaticall...

A circuit arrangement for converting single current, direct current telegraphy signals into double current signals is described. The double current signals operate a double current telegraphy transmission device. The input of a bistable trigger stage is connected in parallel to two connected resistances, which form part of a bridge circuit. The other part of the bridge circuit is formed by a subscriber station. An impedance transformation stage connects the resistances to the bistable trigger ci...

A circuit arrangement for the transmission of telegraphy and data signals at any speed over a line in a direct current transmission system wherein the internal resistances of the transmitters and receivers are mismatched low-ohmically to the line. At least one end station has an internal resistance that is further mismatched extremely low-ohmically to the line.