US2483889A - Superheterodyne receiver with automatic frequency control - Google Patents

Superheterodyne receiver with automatic frequency control Download PDF

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Publication number
US2483889A
US2483889A US661521A US66152146A US2483889A US 2483889 A US2483889 A US 2483889A US 661521 A US661521 A US 661521A US 66152146 A US66152146 A US 66152146A US 2483889 A US2483889 A US 2483889A
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US
United States
Prior art keywords
circuit
frequency
filter
amplifier
carrier
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 - Lifetime
Application number
US661521A
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English (en)
Inventor
Groot Folkert Albert De
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.)
Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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Publication date
Application filed by Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
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Publication of US2483889A publication Critical patent/US2483889A/en
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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H03J7/042—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant with reactance tube
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H03J7/14—Controlling the magnetic state of inductor cores
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H04B1/30—Circuits for homodyne or synchrodyne receivers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H04B1/30—Circuits for homodyne or synchrodyne receivers
    • H04B1/302—Circuits for homodyne or synchrodyne receivers for single sideband receivers

Definitions

  • the damping of the oscillatory circuits is generally reduced with theaid of a back-coupled discharge system or by means of-a discharge system wherein a negative resistance occurs between two electrodes.
  • a filter which comprises one or more oscillatory circuits with reduced damping.
  • the present invention relates to one determined form of construction of' the above-de-- scribed superheterodyne receiver, viz. to a receiver provided with a sharp filter which com-- prises: at least one inductance coil provided with a ferromagnetic core (iron-cored coil) whose self-induction is influenced by the automatic frequency. control. in order to be able-to give the The tuning of this: filter is (Cl. 179--IE71)- cored coils in the above-described manner entails drawbacks since the circuit-arrangement either has. no or little filtering efiect or begins to oscillate.
  • the automatic frequency control due to the elfect of the automatic frequency control, it is not only the selfinduction but in general also the Q of the iron-cored coil and the: Q ofthecircuit that are modified. Since, however, inorder to ensure a satisfactory functioning of the filter, it is necessary to reduce the damping of the'circuit to a high extent, the Q of the circuit must not exhibit great variations; since even comparatively small variations of the Q exert a very great influence on the circuit and consequently on the functioning of the filter.
  • the iron-cored coil is preferably incorporated in the oscillatory circuit with reduced damping in such manner that within the tuning range of the filter the Q- of the said circuit is not or slightly modified.
  • the oscillatory circuit with reduced damping comprises bothan air-coil and an iron-cored coil and if the reduction of the damping is brought about with the aid. of a back-coupled discharge system, this may be achieved by incorporating the whole or part of the iron-cored coil inthe back-coupling circuit of the discharge system by means of which the damping of l the circuit is reduced.
  • the drawing represents the: intermediate-frequency portion of a receiver to which the invention has been applied.
  • An intermediate-frequency amplifying tube I is coupled to the control grid circuit of a discharge tube A through the intermediary of an oscillatory circuit 2, which is tuned to the intermediate-frequency, and of a filter 3, which is constituted by a circuit with reduced damping.
  • the filter 3 is composed of a condenser 5, an iron-cored coil 6 and an air-core coil 7. The reduction of the damping of the circuit 3 is brought about owing to the fact that the circuit 3 is connected in three-point connection :1
  • circuit 3 is connected in regenerative feedback relationship to the tube 4.
  • the discharge tube l is in negative feedback relationship since a resistance 8 which is not shunted for the intermediatefrequency is connected in the cathode lead.
  • the filter 3 is not damped by the presence of this resistance.
  • a circuit 9 which is tuned to the intermediate frequency and which is capacitatively coupled, via a condenser ID, to a diode-detector H' whose low-frequency output voltage is supplied to a low-frequency amplifier (not shown).
  • the circuit 2 has coupled to it a circuit [2 which is also tuned to the intermediatefrequency and to which may be connected two push-pull control rectifiers (diodes) l3 and It.
  • the mid-point of the circuit l2 and the mid-point of the output resistance l5 of the two diodes l3 and Id are connected to a coupling coil i6 which is inductively coupled to the intermediate-frequency circuit 9.
  • the circuits 1, 9 and I2 and the coupling coil i6 form a frequency-responsive network which, jointly with the control rectifiers l3 and I4 connected thereto, forms a device for generating a control voltage for automatic frequency control, which control voltage appears across the above-mentioned output resistance P5.
  • the control voltage is supplied to the control grid of a discharge tube H which is shown as a triode and whose anode current flows through a magnetizing coil [8 of a transformer [9 which comprises a core of high-frequency iron on which a magnetizing coil I8 and the previously described coil 6 are arranged.
  • a magnetizing coil [8 of a transformer [9 which comprises a core of high-frequency iron on which a magnetizing coil I8 and the previously described coil 6 are arranged.
  • the side-band frequencies of the intermediate-frequency signal are greatly attenuated with respect to the carrier wave, owing to which in the case of selective fading the danger of the production of an apparent over-modulation of the signal, which would be attended with a large non-linear distortion of the low-frequency signal, is avoided.
  • the linear distortion caused by the attenuation of the side-band frequencies is suppressed by the proper choice of the frequency characteristic of the low-frequency amplifier.
  • the tuning frequency of the circuit should always correspond within narrow limits to the frequency of the intermediate-frequency carrier wave. This correspondence is ensured by the automatic frequency control, for
  • the filter does no longer function selectively, it is not only the carrier wave but also an appre- Z ciable portion of the side bands that is selected,
  • the iron-cored coil 6 is incorporated in the oscillatory circuit with reduced damping in such manner that within the tuning range of the filter the Q of this circuit does not vary or slightly varies.
  • this is achieved by incorporating part of the iron-cored coil in the back-coupling circuit of the discharge tube 4.
  • the anode circuit of this tube is connected for this purpose to a tap on the iron-cored coil 6.
  • An amplifier circuit arrangement particuto couple said resonant circuit and said filtercir cuit in cascade to the input circuit of said amplifier to' apply asignal voltage of frequency corresponding to said carrier and sideband frequencies tosaidamplifier, means to couple said filter circuit, tosaid amplifier to derive and apply to the inputcircuit of said amplifier a second'signal voltageof frequency corresponding to said carrier frequency to reduce the damping of said filter, means ,coupled to said resonant circuit and the output circuit of said amplifier to produce a frequency control voltage, means responsive to said control voltage to vary the magnetization of said ferromagnetic core to tune said filter sharply to an intermediate frequency corresponding to said carrier frequency,means coupling the output circuit of said amplifier to said filter circuit in regenerative feedback relationship to maintain variations in the quality factor brought about by variations in said control voltage at values at which the stability and selectivity of said filter are substantially constant, and means coupled to the output circuit of said amplifer to derive an output voltage comprising said first signal voltage and said second signal voltage and having carrier frequency components relative to
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of carrier and sideband frequencies, comprising a resonant circuit for translating a first signal voltage having frequency components corresponding to said carrier and saidlsideband frequencies, an amplifier having an input circuit and an output circuit, a filter circuit comprising an inductor having a magnetizable ferromagnetic core and being sharply tuned to a frequency corresponding to said carrier frequency, means to couple said resonant circuit and said filter circuit in cascade to the input circuit of said amplifier to apply a signal voltage of fre-- quency corresponding to saidcarrier and side band frequencies to said amplifier, means to couple said filter circuit to said amplifier to derive and apply to the input circuit of said amplifier a second signal voltage of frequency corresponding to said carrier frequency to reduce the dampingof said filter, means coupled to said resonant circuit and the output circuit of said amplifier to produce a frequency control voltage, means responsive to said control voltage to vary the mag netization of said ferromagnetic core to tune said filter sharply to an intermediate frequency corresponding
  • filter circuit in regenerative feedback relationship to maintain variations in the quality factor brought about by variations in said control voltage at values at which the stability and selectivity of said filter are substantially constant throughout the effective range of said filter, and meanscoupled to the output circuit of said amplifiento: derive an output voltage comprising 75, saidcarrier frequency, means couplingthe output;
  • An amplifier circuit arrangement particularly for use in a receiver for receiving signal voltages of a carrier and sideband frequenciea'comprising a resonant circuit for translating a first signal voltage having frequency components correspondingto said carrier and said sideband fre-, quencies, an amplifier having an input circuit and.v
  • a filter circuit sharply tuned to a frequency corresponding to said carrier frequency
  • saidfilter circuit comprising a'first inductor and a econd inductor having a magnetizable ferromagnetic core connected in series
  • means responsive to said control voltage to vary the magnetization of a said ferromagnetic core to tune said filter sharply to an intermediate frequency corresponding .
  • An intermediate frequency amplifier circuit arrangement particularly for use in a superheterodyne receiver for receiving signal voltages of carrier and sideband frequencies, comprising aresonant circuit for translating a first intermediate frequency signal voltage having frequency components corresponding to said carrier and said sideband frequencies, an electron discharge amplifier tube having a cathode, a control grid and an anode, a filter circuit comprising a first capacitor connected in parallel with a first inductor and a second inductor connected" in series, means to couple the first inductor of said filter circuit to said resonant circuit and between the control grid and cathode of said amplifier tube to apply a signal voltage of frequency corresponding to said carrier and sideband frequencies to said amplifier tube, means to couple said filter circuit to the cathode of said amplifier tube to apply to the control grid of said amplifier tube a second intermediate frequency signal voltage of frequency corresponding to said carrier frequency to reduce the damping of said filter circuit, means coupled to'the anode of said amplifier tube and to said resonant circuit to derive a frequency control voltage, a third
  • An intermediate frequency amplifier circuit arrangement particularly for use in a superheterodyne receiver for receiving signal voltages of carrier and sideband frequencies, comprising a resonant circuit for translating a first intermediate frequency signal voltage having frequency components corresponding to said carrier and said sideband frequencies, a first electron discharge amplifier tube having a cathode, a control grid and an anode, a filter circuit comprising a first capacitor connected in parallel with a first inductor and a second inductor connected in series, means to couple the first into said carrier and sdieband frequencies to said" ductor electromagnetically coupled by means ofa ferromagnetic core to the second inductor of said filter circuit, a second electron discharge tube amplifier to apply said frequency control voltage to said third inductor automatically to vary the magnetization of said ferromagnetic core and to vary the inductance value of said second inductor to tune said filter sharply to an intermediate frequency corresponding to said carrier frequency, means coupling the anode circuit of said first electron discharge tube to said filter circuit in regenerative feedback relationship at a
  • An intermediate frequency amplifier circuit arrangement particularly for use in a superheterodyne receiver for receiving signal voltages of carrier and sideband frequencies, comprising a resonant circuit for translating a first intermediate frequency signal voltage having frequency components corresponding to said carrier and said sideband frequencies, a first electron discharge amplifier tube having a cathode, a control grid and an anode, a filter circuit comprising a first capacitor connected in parallel with a first inductor and a second inductor connected in series, said second inductor having a tapping thereon and a ferromagnetic core, means to couple the first inductor of said filter circuit inductively to said resonant circuit and between the control grid and cathode of said first amplifier tube to apply a signal voltage of frequency corresponding to said carrier and sideband frequencies to said amplifier, means to couple said filter circuit to the cathode of said amplifier tube to apply to the control grid of said first amplifier tube a second intermediate frequency signal voltage of frequency corresponding to said carrier frequency to reduce the damping of said filter circuit, a negative

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Superheterodyne Receivers (AREA)
  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
  • Amplifiers (AREA)
  • Networks Using Active Elements (AREA)
  • Noise Elimination (AREA)
US661521A 1941-08-16 1946-04-12 Superheterodyne receiver with automatic frequency control Expired - Lifetime US2483889A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL102584A NL65489C (xx) 1941-08-16 1941-08-16

Publications (1)

Publication Number Publication Date
US2483889A true US2483889A (en) 1949-10-04

Family

ID=40627386

Family Applications (3)

Application Number Title Priority Date Filing Date
US661521A Expired - Lifetime US2483889A (en) 1941-08-16 1946-04-12 Superheterodyne receiver with automatic frequency control
US661522A Expired - Lifetime US2483314A (en) 1941-08-16 1946-04-12 Superheterodyne receiver comprising automatic frequency control
US662963A Expired - Lifetime US2595931A (en) 1941-08-16 1946-04-18 Superheterodyne receiver with automatic frequency control

Family Applications After (2)

Application Number Title Priority Date Filing Date
US661522A Expired - Lifetime US2483314A (en) 1941-08-16 1946-04-12 Superheterodyne receiver comprising automatic frequency control
US662963A Expired - Lifetime US2595931A (en) 1941-08-16 1946-04-18 Superheterodyne receiver with automatic frequency control

Country Status (7)

Country Link
US (3) US2483889A (xx)
BE (1) BE446845A (xx)
CH (2) CH231618A (xx)
DE (3) DE869223C (xx)
FR (3) FR885191A (xx)
GB (3) GB616358A (xx)
NL (2) NL65489C (xx)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2811639A (en) * 1953-05-26 1957-10-29 Cgs Lab Inc Signal generating apparatus
US2857479A (en) * 1953-03-20 1958-10-21 Bell Telephone Labor Inc Distortion reducing tuned amplifier
US5552036A (en) * 1994-06-01 1996-09-03 Foret; Todd L. Process for reducing the level of sulfur in a refinery process stream and/or crude oil
US20120299392A1 (en) * 2010-05-28 2012-11-29 Keiichi Ichikawa Power Transfer System
US20160336869A1 (en) * 2015-05-13 2016-11-17 Fu-Tzu HSU Magnetoelectric device capable of damping power amplification

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2891158A (en) * 1951-06-30 1959-06-16 Cgs Lab Inc Ferrite stabilizing system
US2882391A (en) * 1954-09-07 1959-04-14 Gen Motors Corp Electric radio tuner
DE1158128B (de) * 1959-04-27 1963-11-28 Robertshaw Fulton Controls Co Empfaenger fuer phasenmodulierte Hochfrequenzschwingungen
US3676582A (en) * 1971-03-03 1972-07-11 Gen Electric Emphasized carrier circuit with integral afc operation

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1642173A (en) * 1921-03-16 1927-09-13 Rca Corp Radio signaling system
US1681532A (en) * 1923-07-02 1928-08-21 Western Electric Co Transmission control
US2121103A (en) * 1935-10-17 1938-06-21 Rca Corp Frequency variation response circuits
US2200038A (en) * 1938-03-19 1940-05-07 Rca Corp Automatic frequency control circuit
US2302893A (en) * 1939-09-29 1942-11-24 Rca Corp Variable inductance arrangement

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB407057A (en) * 1932-09-09 1934-03-09 James Robinson Improvements in or relating to selective receivers for wave signals
US2133849A (en) * 1934-06-07 1938-10-18 Gen Electric Means for tuning receiving systems
GB469077A (en) * 1936-01-10 1937-07-12 James Robinson Improvements in or relating to wireless and like receivers
US2268672A (en) * 1938-05-24 1942-01-06 Radio Patents Corp Selective amplifier
NL63645C (xx) * 1940-02-29

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1642173A (en) * 1921-03-16 1927-09-13 Rca Corp Radio signaling system
US1681532A (en) * 1923-07-02 1928-08-21 Western Electric Co Transmission control
US2121103A (en) * 1935-10-17 1938-06-21 Rca Corp Frequency variation response circuits
US2200038A (en) * 1938-03-19 1940-05-07 Rca Corp Automatic frequency control circuit
US2302893A (en) * 1939-09-29 1942-11-24 Rca Corp Variable inductance arrangement

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2857479A (en) * 1953-03-20 1958-10-21 Bell Telephone Labor Inc Distortion reducing tuned amplifier
US2811639A (en) * 1953-05-26 1957-10-29 Cgs Lab Inc Signal generating apparatus
US5552036A (en) * 1994-06-01 1996-09-03 Foret; Todd L. Process for reducing the level of sulfur in a refinery process stream and/or crude oil
US20120299392A1 (en) * 2010-05-28 2012-11-29 Keiichi Ichikawa Power Transfer System
US9461477B2 (en) * 2010-05-28 2016-10-04 Murata Manufacturing Co., Ltd. Power transfer system
US20160336869A1 (en) * 2015-05-13 2016-11-17 Fu-Tzu HSU Magnetoelectric device capable of damping power amplification
US9712074B2 (en) * 2015-05-13 2017-07-18 Fu-Tzu HSU Magnetoelectric device capable of damping power amplification

Also Published As

Publication number Publication date
CH256781A (de) 1948-08-31
CH231618A (de) 1944-03-31
DE889313C (de) 1953-09-10
FR53545E (fr) 1946-03-04
FR53543E (fr) 1946-03-04
DE869223C (de) 1953-03-02
US2595931A (en) 1952-05-06
GB630692A (en) 1949-10-19
BE446845A (xx)
GB632169A (en) 1949-11-17
GB616358A (en) 1949-01-20
FR885191A (fr) 1943-09-07
DE878971C (de) 1953-04-23
US2483314A (en) 1949-09-27
NL70087C (xx) 1951-08-15
NL65489C (xx) 1949-06-15

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