GB1011370A - Improvements in or relating to frequency shift keying and the like - Google Patents
Improvements in or relating to frequency shift keying and the likeInfo
- Publication number
- GB1011370A GB1011370A GB512563A GB512563A GB1011370A GB 1011370 A GB1011370 A GB 1011370A GB 512563 A GB512563 A GB 512563A GB 512563 A GB512563 A GB 512563A GB 1011370 A GB1011370 A GB 1011370A
- Authority
- GB
- United Kingdom
- Prior art keywords
- frequency
- discriminator
- shift
- signal
- centre
- 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
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/12—Modulator circuits; Transmitter circuits
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
Abstract
1,011,370. Telegraphy. RACAL COMMUNICATIONS Ltd. April 28, 1964 [Feb. 8, 1963], No. 5125/63. Heading H4P. A frequency-shift modulator comprises a keyed frequency-variable oscillator giving an output signal a fraction of which is mixed with a fixed frequency, the resultant signal passing to a discriminator whose output controls the variable oscillator by being fed to it in one or other of two phases in accordance with the keying signal. The control signal thus maintains the oscillator frequency at one or the other shift frequencies. In the embodiment described the fixed frequency is equal to the centre-frequency of the output signal and the discriminator has a centrefrequency equal to the amount of carrier shift. The discriminator may be a centre-tapped parallel-tuned transformer or inductor. The response of the frequency-controlling circuitry is arranged to provide smooth frequency-shifting between mark and space frequencies.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB512563A GB1011370A (en) | 1963-02-08 | 1963-02-08 | Improvements in or relating to frequency shift keying and the like |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB512563A GB1011370A (en) | 1963-02-08 | 1963-02-08 | Improvements in or relating to frequency shift keying and the like |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1011370A true GB1011370A (en) | 1965-11-24 |
Family
ID=9790183
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB512563A Expired GB1011370A (en) | 1963-02-08 | 1963-02-08 | Improvements in or relating to frequency shift keying and the like |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB1011370A (en) |
-
1963
- 1963-02-08 GB GB512563A patent/GB1011370A/en not_active Expired
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