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GB559289A - Improvements relating to frequency modulation - Google Patents

Improvements relating to frequency modulation

Info

Publication number
GB559289A
GB559289A GB16469/42A GB1646942A GB559289A GB 559289 A GB559289 A GB 559289A GB 16469/42 A GB16469/42 A GB 16469/42A GB 1646942 A GB1646942 A GB 1646942A GB 559289 A GB559289 A GB 559289A
Authority
GB
United Kingdom
Prior art keywords
valve
anode
grid
resistance
frequency
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
GB16469/42A
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.)
Marconis Wireless Telegraph Co Ltd
BAE Systems Electronics Ltd
Original Assignee
Marconis Wireless Telegraph Co Ltd
Marconi 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 Marconis Wireless Telegraph Co Ltd, Marconi Co Ltd filed Critical Marconis Wireless Telegraph Co Ltd
Publication of GB559289A publication Critical patent/GB559289A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation
    • H03C3/10—Angle modulation by means of variable impedance
    • H03C3/24—Angle modulation by means of variable impedance by means of a variable resistive element, e.g. tube

Landscapes

  • Amplifiers (AREA)
  • Transmitters (AREA)

Abstract

559,289. Frequency modulation. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Nov. 20, 1942, No. 16469. Convention date, Nov. 21, 1941. [Classes 40 (iii) and 40 (v)] An oscillator of the back-coupled resistance. capacity type is modulated in frequency b) providing a pair of auxiliary valves 23, 24 in series relation across a constant voltage source B, the grid of one valve 24 being connected tc an intermediate point of the source while the other valve 23 functions as a variable resistance in the back-coupling network. The oscillator valve 10 has a resistance-capacity network 19a ..., 21a ... connected between its anode 16 and its control grid 12, and the oscillations developed are at such a frequency that the anode and grid are in phase opposition. One of the shunt resistances 21c includes the anode-cathode path of the valve 23, the grid of which is connected to the signal source. The valve 23 acts as a cathode impedance to the valve 24, so that although the impedance of valve 23 changes, there is substantially no change in its anode voltage, with the result that the amplitude of the oscillation generated does not vary. In a modification, Fig. 2 (not shown), a cathode follower valve is interposed between the valve 10 and the resistance-capacity network. More than one of the resistances 21b ... 21e may include series modulating valves. The signal voltage may comprise speech or music, or it may comprise positive and negative pulses representing black and white in a picture telegraphy system.
GB16469/42A 1941-11-21 1942-11-20 Improvements relating to frequency modulation Expired GB559289A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US419893A US2321269A (en) 1941-11-21 1941-11-21 Frequency modulation

Publications (1)

Publication Number Publication Date
GB559289A true GB559289A (en) 1944-02-11

Family

ID=23664187

Family Applications (1)

Application Number Title Priority Date Filing Date
GB16469/42A Expired GB559289A (en) 1941-11-21 1942-11-20 Improvements relating to frequency modulation

Country Status (2)

Country Link
US (1) US2321269A (en)
GB (1) GB559289A (en)

Families Citing this family (51)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB552039A (en) * 1940-10-30 1943-03-19 Marconi Wireless Telegraph Co Improvements relating to frequency modulation
US2423952A (en) * 1941-12-12 1947-07-15 Press Wireless Inc Frequency modulation
US2480195A (en) * 1942-01-10 1949-08-30 Hartford Nat Bank & Trust Co High-frequency amplifier with controlled load impedance
US2436834A (en) * 1942-11-17 1948-03-02 Edwin K Stodola Phase and frequency modulation
US2418842A (en) * 1943-03-04 1947-04-15 Bell Telephone Labor Inc Scanning oscillator
BE456041A (en) * 1943-05-29
US2506329A (en) * 1944-11-16 1950-05-02 Philco Corp Phase-shift network and oscillator
US2598702A (en) * 1945-01-19 1952-06-03 Jr Martin V Kiebert Sweep compression for use of fm range equipment
US2488410A (en) * 1945-01-26 1949-11-15 Rca Corp Control circuits for alternating current transmission networks
US2463073A (en) * 1945-01-26 1949-03-01 Rca Corp Oscillator
US2551348A (en) * 1945-03-28 1951-05-01 Philco Corp Electrical apparatus
US2568533A (en) * 1945-04-17 1951-09-18 Rca Corp Electronic circuit arrangement
US2543782A (en) * 1945-05-26 1951-03-06 Jr Martin V Kiebert Frequency modulated radio-type distance measuring device
US2474918A (en) * 1945-07-30 1949-07-05 Stromberg Carlson Co Ranging system
NL66753C (en) * 1945-09-01
BE473144A (en) * 1945-09-15
US2527535A (en) * 1945-12-14 1950-10-31 Jr Robert A Emmett Electronic phase shifter
US2523294A (en) * 1946-03-16 1950-09-26 Farnsworth Res Corp Self-tuning amplifier
GB610951A (en) * 1946-04-15 1948-10-22 Marconi Wireless Telegraph Co Improvements in or relating to frequency modulated radio and like transmitters
US2547767A (en) * 1946-06-13 1951-04-03 Rca Corp Variable phase shifter
US2605633A (en) * 1946-07-23 1952-08-05 James D Gow Insulator testing apparatus
US2638550A (en) * 1946-08-10 1953-05-12 Faximile Inc Variable frequency oscillator
US2570758A (en) * 1946-09-04 1951-10-09 Rca Corp Automatic frequency control
NL71104C (en) * 1946-09-20 1952-10-05
US2469837A (en) * 1946-09-26 1949-05-10 Bell Telephone Labor Inc Wave translating system
NL66962C (en) * 1947-02-20 1900-01-01
FR963830A (en) * 1947-03-08 1950-07-21
US2486265A (en) * 1947-03-22 1949-10-25 Bell Telephone Labor Inc Variable frequency oscillator
US2514087A (en) * 1947-04-18 1950-07-04 Lawrence T Phelan Modulated oscillator
BE485401A (en) * 1947-10-21
US2590282A (en) * 1947-11-08 1952-03-25 Stromberg Carlson Co Variable impedance device
BE486127A (en) * 1947-12-03
US2573133A (en) * 1948-08-13 1951-10-30 Halliburton Oil Well Cementing Well logging system
US2496148A (en) * 1948-09-29 1950-01-31 Melpar Inc Frequency modulator and time division multiplex system
US2641741A (en) * 1949-02-21 1953-06-09 Phillips Petroleum Co Crystal controlled modulated oscillator
US2644924A (en) * 1949-09-03 1953-07-07 Gen Electric Frequency modulation system
US2636115A (en) * 1949-12-22 1953-04-21 Rca Corp Frequency shift diversity reception
US2750502A (en) * 1950-12-29 1956-06-12 Rca Corp Cathode-controlled wave generators
US2659000A (en) * 1951-04-27 1953-11-10 Collins Radio Co Variable frequency cyclotron
US2741696A (en) * 1951-08-17 1956-04-10 Gen Electric Co Ltd Panoramic receiver having zero-beat detector
US2716218A (en) * 1952-06-06 1955-08-23 Rca Corp Frequency variation circuit
US2777951A (en) * 1952-12-10 1957-01-15 Sperry Rand Corp Erequency modulating systems for phase-shift oscillators
BE525820A (en) * 1953-01-19
US2800586A (en) * 1953-07-31 1957-07-23 Northrop Aircraft Inc Artificial inductor
US2935700A (en) * 1955-08-01 1960-05-03 Cutler Hammer Inc Frequency modulation systems
US2879388A (en) * 1955-08-23 1959-03-24 Thomas J George Electronic musical instrument
US2858437A (en) * 1955-11-17 1958-10-28 Sylvania Electric Prod Oscillation generator
US2902656A (en) * 1956-04-30 1959-09-01 Bell Telephone Labor Inc Variable-frequency oscillator
US2927735A (en) * 1956-09-19 1960-03-08 Gen Dynamics Corp Frequency-control system
NL236118A (en) * 1958-02-14
US3070762A (en) * 1960-05-02 1962-12-25 Texas Instruments Inc Voltage tuned resistance-capacitance filter, consisting of integrated semiconductor elements usable in phase shift oscillator

Also Published As

Publication number Publication date
US2321269A (en) 1943-06-08

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