Radio receiver with reception-readiness monitoring feature and method
US4499603A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 23, 1983 |
| Grant date | Feb 12, 1985 |
| Priority date | — |
| Expiry date | Mar 23, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08G1/094
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
To monitor the operability of a radio receiver which has special recognition circuitry to recognize warning or emergency announcements, a modulation detector (11) is provided, sensing the change in degree of modulation of a region recognition (RR) signal, which changes its degree of modulation when an announcement recognition (AR) signal is radiated, the degree-of-modulation signal being stored in a memory (flip-flop 12), the output of which controls a transfer switch (6). The transfer switch transfers output from a muting stage (5) in the receiver, which is disabled upon detection of the AR frequency to a tone generator, for application to the amplifier of a warning tone if no change in the degree of modulation of the RR signal has been detected within a predetermined time period, as determined by a timing stage (15). A suitable timing interval is, for example, 24 hours. If such timing signals are received, the tone generator is not enabled, however.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.