Multiplex signal receiver
US4361728A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 9, 1980 |
| Grant date | Nov 30, 1982 |
| Priority date | — |
| Expiry date | Apr 9, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H40/36
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A superheterodyne type multiplex signal receiver for multiplex signal transmission systems for receiving two independent signals transmitted by amplitude modulation and angle modulation of single carriers, and for detecting an intermediate frequency by an intermediate frequency detector when changing the local oscillating frequency by a dial operation to select the received signal. The receiver has a switching circuit so composed that it operates a demodulation circuit which demodulates, from the modulated carrier, the two independent signals, which are then transmitted to two independent audio amplifiers provided at a later stage of an intermediate frequency amplifier for driving two speakers for reception of the multiplex signal, when the intermediate frequency is extremely close to a normally determined frequency. The switching circuit also transmits to the two independent audio amplifiers the demodulated signals obtained from an envelope detection circuit when the intermediate frequency is remote from the normally determined frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.