Tuning circuit for superheterodyne receiver
US4161698A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 11, 1977 |
| Grant date | Jul 17, 1979 |
| Priority date | — |
| Expiry date | Feb 11, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/181
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A fine tuning circuit for a superheterodyne receiver including an oscillator whose output frequency is automatically regulated to the value of the rated frequency when the frequency of the oscillator deviates from the rated tuning frequency assigned the receiving channel by means of a control arrangement including a counter for periodically producing a count representative of the oscillator output frequency in a manner such that successive counting states of the counter correspond to oscillator frequency differences which are smaller than the frequency differences between adjacent rated tuning frequency values and with selected counting states being associated with the rated tuning frequency values, and a signal generating arrangement for deriving the control voltage from the counting state of the counter. The counter provides its count in a coded form and the signal generating arrangement is responsive to only part of the counter states which appear when there are deviations from the rated frequency to generate the control voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.