GB1011370A - Improvements in or relating to frequency shift keying and the like - Google Patents

Improvements in or relating to frequency shift keying and the like

Info

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
Application number
GB512563A
Inventor
Peter Maitland
Norman Elson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Racal Communications Ltd
Original Assignee
Racal Communications Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Racal Communications Ltd filed Critical Racal Communications Ltd
Priority to GB512563A priority Critical patent/GB1011370A/en
Publication of GB1011370A publication Critical patent/GB1011370A/en
Expired legal-status Critical Current

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.
GB512563A 1963-02-08 1963-02-08 Improvements in or relating to frequency shift keying and the like Expired GB1011370A (en)

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)

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