Abstract: A two-way CATV system is easy of maintenance, stable of a transmission quality and capable of restraining inter-modulation distortion noises of downstream RF signal carriers which are caused by non-linearity of electric contact members of coaxial connectors among upstream ingress noises becoming a problem when performing communications services by utilizing a CATV transmission path. The two-way CATV system comprises at least one bidirectional amplifier provided on a CATV transmission path for connecting a CATV center station to a subscriber home, a bias voltage superposing element for superposing, with a bias voltage, a downstream signal transmitted along a coaxial transmission path subordinate to an amplifier at the terminal among the bidirectional amplifiers, and a bias current adjusting load element, provided at the end of the coaxial transmission path, for setting the bias current corresponding to an application of the bias voltage superposed by the bias voltage superposing element.

Abstract: A cordless loud-speaking telephone of the present invention is shaped to be placed on a table or desk or to be suspended from a ceiling. Unlike cordless portable telephones of the handy transceiver type, it enables hands-free talking or communication through a receiving speaker and a transmitting microphone located outside a casing. An antenna conductor and counterpoises are projected from the casing, and a microphone is attached to the counterpoises or the antenna conductor such that the microphone is separated as remotely as possible from the speaker in the casing. As a result, howling and echo which disturb talking or communication via the telephone can be suppressed.

Abstract: A phone conference system which includes a plurality of microphones and a speaker or speakers which are connected to a telephone. In the phone conference system, a required number of units are connected in cascade fashion. Each unit includes a speaker or speakers, connected via an amplifier to a receiving line, a preamplifier-mixer for unifying the outputs of the microphones, and a summing amplifier unifying the output of the preamplifier-mixer and the output a microphone or microphones from another unit.