US2073345A - Superheterodyne receiver - Google Patents

Superheterodyne receiver Download PDF

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Publication number
US2073345A
US2073345A US59021A US5902136A US2073345A US 2073345 A US2073345 A US 2073345A US 59021 A US59021 A US 59021A US 5902136 A US5902136 A US 5902136A US 2073345 A US2073345 A US 2073345A
Authority
US
United States
Prior art keywords
frequency
circuit
condenser
range
frequencies
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
US59021A
Other languages
English (en)
Inventor
Johnson John Kelly
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.)
BAE Systems Aerospace Inc
Original Assignee
Hazeltine Corp
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
Priority to NL50423D priority Critical patent/NL50423C/xx
Priority to NL51540D priority patent/NL51540C/xx
Priority to NL73647D priority patent/NL73647C/xx
Priority claimed from US726931A external-priority patent/US2073344A/en
Priority to GB12164/35A priority patent/GB442477A/en
Priority to FR790235D priority patent/FR790235A/fr
Priority to DEH143758D priority patent/DE754303C/de
Priority to US30999A priority patent/US2115463A/en
Application filed by Hazeltine Corp filed Critical Hazeltine Corp
Priority to US59021A priority patent/US2073345A/en
Publication of US2073345A publication Critical patent/US2073345A/en
Application granted granted Critical
Priority to GB1517/53A priority patent/GB740375A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/0153—Electrical filters; Controlling thereof
    • H03H7/0161—Bandpass filters
    • H03H7/0169—Intermediate frequency filters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J9/00—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction
    • F16J9/12—Details
    • F16J9/20—Rings with special cross-section; Oil-scraping rings
    • F16J9/206—One-piece oil-scraping rings
    • 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
    • H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
    • H04B1/14—Automatic detuning arrangements
    • 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
    • H04B1/26—Circuits for superheterodyne receivers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/17—Structural details of sub-circuits of frequency selective networks
    • H03H7/1741—Comprising typical LC combinations, irrespective of presence and location of additional resistors
    • H03H7/1775—Parallel LC in shunt or branch path
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/01—Frequency selective two-port networks
    • H03H7/17—Structural details of sub-circuits of frequency selective networks
    • H03H7/1741—Comprising typical LC combinations, irrespective of presence and location of additional resistors
    • H03H7/1791—Combined LC in shunt or branch path

Definitions

  • This invention relates to oscillation circuits tunable over a range of frequencies by an adjustable reactance thereof to select a desired 'fre-.
  • oscillation frequency may be effected by provid- 5 ing in connection with the circuit adjustable auxiliary impedance means.
  • the reactance ofthe adjustable tuningelement of the circuit varies within wide limits 'as the element is adjusted to tune the circuit over its range.
  • the effectiveness of the auxiliary impedance means in adjusting the resonant frequency of circuit is ordinarily dependent on the relative magnitude of its impedance and those of the main reactance elements of the circuit. Therefore, the effectiveness of the auxiliary impedance means tends to vary in accordance with the frequency to which the eircuit is tuned and, in order to obtain equal adjustments of the resonant frequency of circuit relative to different selected frequencies, different degrees of adjustment of the auxiliary means would ordinarily be required. It is highly desirable, however, that equal adjustments of said auxiliary impedance means willeifect equal ad-- justments of the resonant frequency of the circuit for all frequencies of the range through I which the circuit may be tuned. J)
  • the primary object, therefore, of the present invention to provide a circuit arrangement w by. the resonant frequency of an oscillato any selected frequency tion circuit, tunable within a predetermined range of frequencies may be adjusted relative to the selected frequency, and independently of the tuning means over a small fraction v v of the range, ,equal adjustmentsof the adjusting means effecting equal changes of the resonant frequency of the circuit relative to the selected frequency for all frequencies of the range.
  • an oscillation circuit is provided with auxiliary ad-' justable impedance means, independent of the.
  • the tuning element of the circuit and coupled to the circuit to adjust the resonant frequency there-- .of.
  • the auxiliary means and its coupling to the circuit are so proportioned" and arranged that the effectiveness thereof is substantially constant and independent of the frequency to which the circuit is tuned by its tuning element.
  • the oscillation circuit is comprised in an oscillation system
  • the auxiliary adjustable impedance means comp dses a variable condenser connected across a port-ion of the capacitance of the circuit through at least a. portion ofthe inductance of the system, and the auxiliary'condenser and .its'
  • FIG. 1 is a circuit diagram of a complete superheterodyne receiver
  • an antenna and ground system "-1 l; a radiofrequencyamplifier ii, an oscillator-modulator tube If; an intermediate-frequency amplifier I4; and a detector, audio-frequency amplifier and loud+speaker II.
  • the devices i2, i4 and I! are indicated only schematically, since they consti-' tute no part of this invention and may be of any conventional design.
  • the oscillator-modulator tube ll is of the hexode type and may take the form disclosed in Patent No. 2,015,327 issued to Hamid A. Wheeler on September 24, 1935.
  • the tube contains a signal input grid it coupled to the radio-frequency amplifier I! through a radio-frequency transformer ll, the secondary .coil of which is tunable to signal channels of the broadcast range by a variable condenser l8.
  • an oscillation system l9 embodying the present invention, which includes a coil 20 connected from an inner screen 2
  • a condenser 24 is connected betweenground and an intermediate point 25 of the coil.
  • a source of positive operating voltage, designated +18, is connected through a resistor 26 to the point 25 for supplying a proper direct voltage to the screen 2
  • a variable condenser 21 is connected between ground and' the upper end of coil 28. .
  • the condensers 24 and 21 and the portion of coil above point constitute a resonant circuit which determines the frequency of the oscillation system, this frequency being variable by means of condenser 21.
  • the oscillator-modulator circuit justdescribed is similar to those 20 which are more fully described in United States Letters Patent No. 1,958,027, granted May 8,
  • condenser 28 there is connected a relatively small variable con- 25 denser 28 between ground and a second intermediate point 29 of coil 20 which is outside the resonant frequency-determining circuit.
  • condenser 28 is connected across condenser 24 and a portion 30 of coil 20 which is outside the resonant circuit.
  • Modulation occurs between the received signal.
  • variable condensers l8 and 21 are ganged together for simultaneous operation by means of a unicontrol device indicated generally by U.
  • a coupling system ,3l connected between the anode of tube l8 and the input of the intermediate-frequency amplifier I4 is tuned to pass a fixed intermediate-frequency band.
  • is shown graphically in Fig. 2.
  • the intermediate carrier I 5 frequency is represented by the vertical line A which is taken as kilocycles in this case.
  • the coupling system is adjusted to select and pass an intermediate-frequency channel band 8 kilocycles wide, from 171 to 179 kilocycles, these two edges of the selected band being indicated by the broken lines B and C,.respectively.
  • the function of the condenser 28 associated with the oscillator circuit is to shift the oscillator frequency in either direction by any desired amount up to the width of a side band,-without altering the radio-frequency channel selected. Since the side-band width for the case under consideration is 4 kilocycles, this should be the limit of frequency shift due to condenser 28. It will be noted that this range of adjustment is a very small fraction' of the tuning range of the system, which is usually of the order of 1000 kilocycles to cover the general broadcast. band.
  • the oscillator frequency will be considered to be 175 kilocycles higher than the selected signal frequency, when condenser 28 is in its neutral or normal position.
  • the dotted line D in Fig. 2 shows the location of the intermediate carrier frequency when the oscillator frequency is shifted downward by 3 kilocycles from normal. It is contemplated that the intermediate frequency represented by line D may be shifted at will to any position between the limits of lines B and C.
  • the audio-frequency fidelity is improved without increasing the transmitted band width; although it should be noted that at the same time frequencies corresponding to low audio frequencies (0 to 1000 in this case) are transmitted with better efliciency than the frequencies corresponding to higher. audio frequencies. The reason for this is that frequencies corresponding to low audio frequencies are transmitted by'both side bands.
  • condenser 28 is particularly advantageous. By reason of its connection across at least some of the capacitance of the frequency-determining circuit and across inductance which is outside the frequencydetermining circuit, equal adjustments or variations of the capacitance of condenser 28 produce equal frequency shifts or adjustments at all frequencies of the tuning range. Such would not be the case if condenser 28 were connected across inductance alone or capacitance alone.
  • the condenser 24 has a maximum effect in the circuit with maximum adjustment when the condenser 27 is adjusted to its maximum value to provide a minimum reactance for tuning the circuit to a lower frequency of the-range, and has a. minimum effect when condenser 28 were connected only across the condenser 24 so that its effect would vary with frequency in the same manner as the condenser 24,
  • the resultant capacitive reactance of the auxiliary frequency adjusting circuit in parallel with the condenser is modified so that equal adjustments of condenser 2. effect equal changes in the-resonant frequency of the circuit at all frequenciesof its tuning range.
  • the intermediate carrier frequency may be shifted in either direction.
  • the direction chosen for the shift will ordinarily be opposite that in whichaninterferingsiznalmayhappentober present. 7
  • auxiliary impedance means being adjustable and said means being connected in parallel with at least a part of the reactance of said. circuit and the reactance of said auxiliary means being so related to that of said part of said circuit with which it is connected in pa'r'allel that equal adjustments of said adjustable part of said auxiliary impedance means eflects substantially equal adjustments of the resonant frequency of 4.
  • An oscillation system comprising a vacuum tubeand an oscillationcircuit, tunable over-a range of frequencies,- associatedwith said tube and including an adjustable reactance element for tuningsald circuit to a selected frequency of said range. and means adjustable-independently of said tuning element for adjusting the resonant frequency of said circuit relative to said selectedfrequency over asmall fraction of said range,
  • auxiliary adjustable impedance means coupled to said circuit.
  • the impedance ofsaid auxiliaryimpedance means being so related to its coupling to said circuit that equal adjustments thereof effect substantially equal adjustments of the frequency generated by said system for all 6,.
  • An oscillation circuit timable over offrequencies and including inductance.
  • variable capacitance means effectively connected across two points of said inductance for tuning said circuit to a selected frequency of said misc, s'aid capacitance means having an intermediate connection point, 'andmeans adjustable independently of said variable capacitance means for adjusting the resonantfrequency ofsaid circult relativeto said selected frequency over a small fraction of said range, comprising an auxa range iliary variable condenser connected between a third point of said inductance and said intermediate point of said capacitance means.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
  • Channel Selection Circuits, Automatic Tuning Circuits (AREA)
  • Superheterodyne Receivers (AREA)
  • Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
US59021A 1934-05-22 1936-01-14 Superheterodyne receiver Expired - Lifetime US2073345A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
NL50423D NL50423C (is") 1934-05-22
NL51540D NL51540C (is") 1934-05-22
NL73647D NL73647C (is") 1934-05-22
GB12164/35A GB442477A (en) 1934-05-22 1935-04-23 Superheterodyne receiver for wireless reception
FR790235D FR790235A (fr) 1934-05-22 1935-05-18 Récepteur hétérodyne pour la radio-diffusion
DEH143758D DE754303C (de) 1934-05-22 1935-05-22 UEberlagerungsempfaenger zum Empfang modulierter Traegerschwingungen
US30999A US2115463A (en) 1934-05-22 1935-07-12 Superheterodyne receiver
US59021A US2073345A (en) 1934-05-22 1936-01-14 Superheterodyne receiver
GB1517/53A GB740375A (en) 1934-05-22 1953-01-19 An improved oil scraping ring assembly

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US726931A US2073344A (en) 1934-05-22 1934-05-22 Superheterodyne receiver
US59021A US2073345A (en) 1934-05-22 1936-01-14 Superheterodyne receiver

Publications (1)

Publication Number Publication Date
US2073345A true US2073345A (en) 1937-03-09

Family

ID=26738271

Family Applications (1)

Application Number Title Priority Date Filing Date
US59021A Expired - Lifetime US2073345A (en) 1934-05-22 1936-01-14 Superheterodyne receiver

Country Status (5)

Country Link
US (1) US2073345A (is")
DE (1) DE754303C (is")
FR (1) FR790235A (is")
GB (1) GB442477A (is")
NL (2) NL50423C (is")

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2813155A (en) * 1954-02-23 1957-11-12 Motorola Inc Tone control for radio-phonograph combination
US3231840A (en) * 1962-04-25 1966-01-25 Hammond Organ Co Tuning coil arrangement

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE485660C (de) * 1925-10-08 1929-11-06 Radiofrequenz G M B H Zwischenfrequenzverstaerker unter Verwendung von frequenzlinearen Abstimmitteln
NL38500C (is") * 1932-07-24

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2813155A (en) * 1954-02-23 1957-11-12 Motorola Inc Tone control for radio-phonograph combination
US3231840A (en) * 1962-04-25 1966-01-25 Hammond Organ Co Tuning coil arrangement

Also Published As

Publication number Publication date
NL50423C (is")
GB442477A (en) 1936-02-10
FR790235A (fr) 1935-11-16
DE754303C (de) 1953-05-18
NL51540C (is")

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