Noise blanker with variable rate-shut-off and/or variable blanking threshold level
US4154980A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 1977 |
| Grant date | May 15, 1979 |
| Priority date | — |
| Expiry date | Aug 29, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/345
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A noise blanker circuit for a stereo radio receiver is disclosed herein. The noise blanker circuit detects noise impulses in a received radio signal. When the magnitudes of these detected noise impulses exceed a predetermined threshold level corresponding noise blanking pulses are produced which are coupled to a gate means. The gate means receives the received radio signal and selectively passes and blocks this signal in response to the noise blanking pulses such that the output of the gate means is essentially free of noise impulses. A manually adjusted actuator is provided for selectively altering the predetermined threshold level of the noise blanker circuit such that the most efficient mode of noise blanking can be implemented. In addition, rate shut-off circuitry is provided to prevent the production of noise blanking pulses when the detected noise impluses occur at a repetition rate exceeding a maximum repetition rate. The manually adjustable actuator is illustrated as comprising either the tone control actuator or the stereo-monaural selection switch actuator of a radio receiver. Another embodiment shows automatic threshold level and/or repetition rate selection linked to st…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.