GB648129A - Improvements in and relating to frequency modulation detectors - Google Patents

Improvements in and relating to frequency modulation detectors

Info

Publication number
GB648129A
GB648129A GB30918/48A GB3091848A GB648129A GB 648129 A GB648129 A GB 648129A GB 30918/48 A GB30918/48 A GB 30918/48A GB 3091848 A GB3091848 A GB 3091848A GB 648129 A GB648129 A GB 648129A
Authority
GB
United Kingdom
Prior art keywords
receiver
tune
frequency modulation
nov
reduce
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
GB30918/48A
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.)
British Thomson Houston Co Ltd
Original Assignee
British Thomson Houston Co 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 British Thomson Houston Co Ltd filed Critical British Thomson Houston Co Ltd
Publication of GB648129A publication Critical patent/GB648129A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D3/00—Demodulation of angle-, frequency- or phase- modulated oscillations
    • H03D3/02—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal
    • H03D3/06—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal by combining signals additively or in product demodulators
    • H03D3/12—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal by combining signals additively or in product demodulators by means of discharge tubes having more than two electrodes

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Channel Selection Circuits, Automatic Tuning Circuits (AREA)

Abstract

648,129. Frequency modulation. BRITISH THOMSON-HOUSTON CO., Ltd. Nov. 29, 1948, No. 30918. Convention date, Nov. 29, 1947. [Class 40 (v)] In order to reduce the response of a F.M. receiver when off-tune, the rectifiers 9, 10 of a phasing or other discriminator of normal type are provided with control grids 20, 21, each of which is connected to its own cathode by an audio byepass condenser 23, 25, and to the opposite cathode by a resistor 22, 24. When the receiver is slightly mis-tuned, there is a D.C. voltage between the two cathodes, which is transferred to the opposite grids, in such sense as to reduce the current flowing through the more active rectifier. In this way, the off-tune output of the receiver is reduced below its normal in-tune output, and correct tuning may be obtained by listening for maximum output.
GB30918/48A 1947-11-29 1948-11-29 Improvements in and relating to frequency modulation detectors Expired GB648129A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US648129XA 1947-11-29 1947-11-29

Publications (1)

Publication Number Publication Date
GB648129A true GB648129A (en) 1950-12-28

Family

ID=22058418

Family Applications (1)

Application Number Title Priority Date Filing Date
GB30918/48A Expired GB648129A (en) 1947-11-29 1948-11-29 Improvements in and relating to frequency modulation detectors

Country Status (1)

Country Link
GB (1) GB648129A (en)

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