Method and apparatus for providing a squelch function on narrow band radio receivers
US6374095B1 · kind B1 · utility
5Cited by
10References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 7, 1997 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Nov 7, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/344
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Squelch circuitry for narrow band audio receivers which uses a sub-audible tone or coded signal to modulate the intermediate frequency in accordance with the presence of a desired broadcast signal and then detects the sub-audible tone frequency or coded signal in the modulated IF frequency to control the audio output of the receiver to an off condition when there is excessive noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.