Controlled local oscillator with apparatus for extending its frequency range
US4288875A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 8, 1980 |
| Grant date | Sep 8, 1981 |
| Priority date | — |
| Expiry date | Feb 8, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J5/244
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A tuner for a television receiver includes a voltage controlled local oscillator for tuning VHF channels comprising a transistor arranged in a common base amplifier configuration and a parallel tuned circuit including a varactor diode responsive to a tuning voltage and a first inductor configuration for the low VHF band and a second inductor configuration for the high VHF band connected between the collector and emitter electrodes of the transistor. A second varactor diode also responsive to the tuning voltage is connected between the emitter and base electrodes of the transistor to expand the range of the local oscillator in its high VHF configuration to permit tuning of channels in a midband cable band between the low and high VHF bands without the need for a third inductor configuration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.