GB537699A - Improvements in frequency modulation systems - Google Patents

Improvements in frequency modulation systems

Info

Publication number
GB537699A
GB537699A GB3967/41A GB396741A GB537699A GB 537699 A GB537699 A GB 537699A GB 3967/41 A GB3967/41 A GB 3967/41A GB 396741 A GB396741 A GB 396741A GB 537699 A GB537699 A GB 537699A
Authority
GB
United Kingdom
Prior art keywords
frequency
grid
valve
screen
amplitude
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
GB3967/41A
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.)
PRESS WIRELESS Inc
Original Assignee
PRESS WIRELESS Inc
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 PRESS WIRELESS Inc filed Critical PRESS WIRELESS Inc
Publication of GB537699A publication Critical patent/GB537699A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation
    • H03C3/38—Angle modulation by converting amplitude modulation to angle modulation
    • 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
    • H03D3/26—Demodulation of angle-, frequency- or phase- modulated oscillations by means of sloping amplitude/frequency characteristic of tuned or reactive circuit
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B14/00—Transmission systems not characterised by the medium used for transmission
    • H04B14/002—Transmission systems not characterised by the medium used for transmission characterised by the use of a carrier modulation
    • H04B14/006—Angle modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B14/00—Transmission systems not characterised by the medium used for transmission
    • H04B14/08—Transmission systems not characterised by the medium used for transmission characterised by the use of a sub-carrier
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/00095—Systems or arrangements for the transmission of the picture signal
    • H04N1/00103—Systems or arrangements for the transmission of the picture signal specially adapted for radio transmission, e.g. via satellites
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/04—Systems for the transmission of one television signal, i.e. both picture and sound, by a single carrier
    • H04N7/045—Systems for the transmission of one television signal, i.e. both picture and sound, by a single carrier the carrier being frequency modulated

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • General Physics & Mathematics (AREA)
  • Transmitters (AREA)
  • Amplifiers (AREA)
  • Amplitude Modulation (AREA)

Abstract

537,699. Frequency-modulation; copying telegraphy. PRESS WIRELESS, Inc. Dec. 27, 1939, No. 3967/41. Convention date, Oct. 27, 1939. Divided out of 537,689. Drawings to Specification. [Classes 40 (iii) and 40 (v)] In a frequency modulating system used in copying telegraphy &c., variable-amplitude signals vary the plate-resistance or capacitance of a grid-controlled valve connected in the frequency-determining circuit of an oscillator, the valve being of the screen-grid type and having its anode directly connected to the screen grid. A pair of oscillators may be used, one generating a fixed frequency of, say, 600,000 whilst the frequency of the other may be varied from 601,800 to 603,000 by the amplitude-modulated signals, the outputs of each valve being applied to separate grids of a heptode mixer, the output beat frequency of which varies from 1800 to 3000 and is applied through an amplifier to a radio-transmitter. The circuits described are identical with part of those described in Specification 537,689.
GB3967/41A 1939-10-27 1939-12-27 Improvements in frequency modulation systems Expired GB537699A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US301563A US2299937A (en) 1939-10-27 1939-10-27 Wave signaling system
US434498A US2398054A (en) 1939-10-27 1942-03-13 Modulating method and apparatus
US459759A US2378373A (en) 1939-10-27 1942-09-26 Signal receiving and reproducing system

Publications (1)

Publication Number Publication Date
GB537699A true GB537699A (en) 1941-07-02

Family

ID=27404822

Family Applications (2)

Application Number Title Priority Date Filing Date
GB3967/41A Expired GB537699A (en) 1939-10-27 1939-12-27 Improvements in frequency modulation systems
GB32890/39A Expired GB537689A (en) 1939-10-27 1939-12-27 Improvements in wave signalling systems, particularly applicable to facsimile telegraphy

Family Applications After (1)

Application Number Title Priority Date Filing Date
GB32890/39A Expired GB537689A (en) 1939-10-27 1939-12-27 Improvements in wave signalling systems, particularly applicable to facsimile telegraphy

Country Status (3)

Country Link
US (3) US2299937A (en)
FR (1) FR863144A (en)
GB (2) GB537699A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH269361A (en) * 1947-04-15 1950-06-30 Radio Electr Soc Fr Very large relative bandwidth frequency discriminator.
US2673891A (en) * 1949-02-17 1954-03-30 Bell Telephone Labor Inc Control of transmission in two-way telephotograph systems
NL169675B (en) * 1952-05-17 Imp Tobacco Group Ltd DEVICE FOR TREATING A SHEET OF FIBER MATERIAL, AS WELL AS AN SUCH TREATED FIBER MATERIAL.

Also Published As

Publication number Publication date
US2398054A (en) 1946-04-09
US2299937A (en) 1942-10-27
US2378373A (en) 1945-06-12
GB537689A (en) 1941-07-02
FR863144A (en) 1941-03-24

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