Double superheterodyne tuner
US4661998A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 1984 |
| Grant date | Apr 28, 1987 |
| Priority date | — |
| Expiry date | Sep 19, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D9/0658
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A compact or miniaturized well-shielded double superheterodyne tuner is provided, wherein an input circuit portion, a first mixing portion, a first intermediate frequency bandpass filter, a second mixing portion and an output circuit portion are mounted in separated casings. The first mixing portion and the second mixing portion are provided on printed boards and each mounted on a bottom plate of the casing. The casings containing the first and second mixing portion are arranged in a manner such that grounded surfaces of the printed boards contained in the casings are arranged face to face. The casing containing the bandpass filter is contacted adjacently to a common face of the face to face casings. Each of the casings containing the input and output circuit portions is located adjacently to each of faces common to the face to face casings and the filter containing casing. Some structual improvements are also provided for simplifying the manufacture and adjustment of the tuner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.