GB658671A - Multi-channel radio monitoring receiver - Google Patents
Multi-channel radio monitoring receiverInfo
- Publication number
- GB658671A GB658671A GB3830/49A GB383049A GB658671A GB 658671 A GB658671 A GB 658671A GB 3830/49 A GB3830/49 A GB 3830/49A GB 383049 A GB383049 A GB 383049A GB 658671 A GB658671 A GB 658671A
- Authority
- GB
- United Kingdom
- Prior art keywords
- oscillator
- frequency
- oscillations
- amplifier
- radio
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
- H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
- H03J7/18—Automatic scanning over a band of frequencies
- H03J7/32—Automatic scanning over a band of frequencies with simultaneous display of received frequencies, e.g. panoramic receivers
Landscapes
- Circuits Of Receivers In General (AREA)
Abstract
658,671. Monitoring radio apparatus. RADIO CORPORATION OF AMERICA. Feb. 11, 1949, No. 3830. Convention date, Feb. 12, 1948. [Class 40 (v)] A monitoring system for a plurality of signal channels comprises a superheterodyne receiver with means for amplitude-modulating the locally-produced oscillations with a waveform having a fundamental frequency equal to that of the separation between the channels. In the Figure, oscillations from radio frequency amplifier 10 are heterodyned in mixer 12 with oscillations from oscillator 14, and then applied to the normal I.F. amplifier, detector, audio amplifier and output stages 17, 18, 20, 22. The oscillations from oscillator 14 are amplitudemodulated by means of a stable oscillator 16, so that for a sine wave modulation frequency, the output from oscillator 14 comprises the basic frequency and two side bands. Consequently, supposing the frequency of oscillator 16 to be 10 kc/s., three incoming signals to aerial 24, say of frequencies 2330, 2340, 2350 kc/s., which are separated by a frequency equal to the fundamental frequency of oscillator 16, may be selected by the intermediate frequency amplifier and applied to the loudspeaker 22 for monitoring purposes. The waveform from oscillator 16 may be complex, the presence of harmonics enabling a larger number of signal channels to be received, and the fundamental frequency may be greater or less than the bandwidth of the intermediate frequency amplifier. A switch 15 is provided, so that oscillator 16 may be disconnected, the arrangement then being used as a conventional receiver.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US658671XA | 1948-02-12 | 1948-02-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB658671A true GB658671A (en) | 1951-10-10 |
Family
ID=22065670
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB3830/49A Expired GB658671A (en) | 1948-02-12 | 1949-02-11 | Multi-channel radio monitoring receiver |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB658671A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2096875A1 (en) * | 1970-07-09 | 1972-03-03 | Thomson Csf |
-
1949
- 1949-02-11 GB GB3830/49A patent/GB658671A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2096875A1 (en) * | 1970-07-09 | 1972-03-03 | Thomson Csf |
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