Abstract: A seismic telemetry system employing frequency division multiplexing techniques is disclosed. Analog seismic data are received by remote data acquisition units (RDAU's) converted to digital form and stored in the RDAU's. The data are transmitted via a transmission line to a central station for recording. The RDAU's are connected at randomly selectable locations along the transmission line. Either an RF command or digital strobe signal is used to interrogate the RDAU's from the central station. Each RDAU responds on a separate RF carrier frequency, modulated by the previously stored digital data. The data from each RDAU, therefore, need not be separated along the transmission line from the data received from other RDAU's. At a central station, the data signals are demultiplexed and recorded. Use of high-impedance transmitters and receivers permits the transmission line to operate in flat-line mode.

Abstract: This invention is a connector for making electrical connections between separate sections of cable in a line, a section of cable and a tap line, or leads of a cable to be terminally joined. The connector, which minimizes transmission noise and cross talk problems in these connections, comprises a nonconductive base slotted to accommodate the cable, sharp electrical contact pins or prongs in the base, extending up into the slot, and a nonconductive member which slides through an opening in the base, transverse to and through the slot, thereby forcing a previously inserted cable against the contact pins or prongs to make electrical contact.