US2095035A - Superheterodyne receiver - Google Patents

Superheterodyne receiver Download PDF

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Publication number
US2095035A
US2095035A US702912A US70291233A US2095035A US 2095035 A US2095035 A US 2095035A US 702912 A US702912 A US 702912A US 70291233 A US70291233 A US 70291233A US 2095035 A US2095035 A US 2095035A
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US
United States
Prior art keywords
frequency
circuit
difference
oscillator
circuits
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
US702912A
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English (en)
Inventor
Posthumus Klaas
Weyers Theodorus Josephus
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.)
RCA Corp
Original Assignee
RCA Corp
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Filing date
Publication date
Application filed by RCA Corp filed Critical RCA Corp
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Publication of US2095035A publication Critical patent/US2095035A/en
Anticipated expiration legal-status Critical
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning
    • H03J3/28—Continuous tuning of more than one resonant circuit simultaneously, the tuning frequencies of the circuits having a substantially constant difference throughout the tuning range

Definitions

  • the present invention relates to oscillator circuits for superheterodyne receivers, and particularly to oscillator circuits for superheterodyne receivers for obtaining a constant intermediate frequency.
  • a local oscillator circuit consisting of two parallel branches comprising a series and parallel connection of condensers and a self-inductance respectively, as is shown in Fig. 1.
  • the tuning device of the local oscillator circuit is preferably mechanically coupled with the tuning device of the circuits tuned to the signal to be received in order to obtain the simplest possible adjustment of the receiving set.
  • Such tuning has the drawback that the difference between the resonance frequencies of the oscillator circuit and of the circuit tuned to the signal to be received is for all the frequencies not equal to the intermediate frequency.
  • Figure 2 shows the difference of these resonance frequencies for the frequency range to be received, said difference be ing designated by the difference frequency V V1 is the lowest, V2 the highest frequency to be received, and Vm is the intermediate frequency to which the intermediate frequency circuits are tuned.
  • the elements of the circuits are preferably so taken that for V3 and for V4 the differences between V and Vm are equal in absolute value.
  • V2 3V1 this difference is for V3, and for V4 about 1.5% of Vm.
  • the tuning members are adjusted in such manner that the oscillator frequency amounts to V3-1-Vm.
  • the tuning is substantially determined by the most selective element of the receiving appara' tus, in the present case by the intermediate frequency circuits.
  • the frequency V3 to be received differs by from the resonance frequency of the high-frequency circuits as is shown in Figure 3.
  • the curve a represents the resonance curve of the high frequency circuits where the resonance frequency is V1.
  • V3 is the frequency to be received
  • V3+Vm is the oscillator frequency, the difference between V3+Vm and V1 being V T00 large a difference between V and Vm results in a reduction of the amplification and in distor-.
  • the maximum intermediate frequency which may be employed amounts to 100 KC/sec.
  • the object of the present invention is to form the local oscillator circuit in such manner that in all the positions of the tuning members the difference between the resonance frequencies of the circuits tuned to the frequency to be received and of the oscillator, circuit is as much as possible equal to the intermediate frequency, and 5 5 more particularly that with the same intermediate frequency the maximum value of this difference is smaller than in the usual circuit-arrangement, and that consequently with a constant maximum difference between V and Vm the in- :20 termediate frequency Vm may be higher.
  • Fig. l is a circuit arrangement of a conventional superheterodyne receiver showing the prior art construction of the local oscillator, 25
  • Figs. 2 and 3 show characteristics of the receiver of Fig. 1,
  • Fig. 4 shows one form. of the invention applied to the local oscillator network of the receiver in Fig. 1, 30
  • Fig. 5 illustrates a characteristic of the circuit of Fig. 4,
  • Fig. 6 shows another modification
  • Fig. 7 illustrates the characteristic thereof
  • Fig. 8 shows a modification of the arrangement :35 of Fig, 6, Fig. '7 illustrating its characteristic
  • Fig. 9 shows another modification
  • Fig. 10 illustrating its characteristic
  • Fig. 14 shows still another modification, Fig. 15 40 depicting its characteristic.
  • Theeffect of the resistance R1 is consequently an increase of'the virtual resistanceof the circuit (which with an oscillator circuitis no preponderantfdrawback), and an increase of the virtual ca pacity in the case of a decreasing frequency.
  • The, result aimed at may consequently be obtai'nedgby giving the resistance R1 such a'value so that for the. frequency V1 thevalue ni w cz'? is no longer very large relatively to 1 e.' g. fl).
  • Figure 14 represents a combination of the circuit arrangements of Figures 4,;
  • V V first detector having a means tunable over.

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  • Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
US702912A 1933-01-02 1933-12-18 Superheterodyne receiver Expired - Lifetime US2095035A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE424714X 1933-01-02

Publications (1)

Publication Number Publication Date
US2095035A true US2095035A (en) 1937-10-05

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ID=6476940

Family Applications (1)

Application Number Title Priority Date Filing Date
US702912A Expired - Lifetime US2095035A (en) 1933-01-02 1933-12-18 Superheterodyne receiver

Country Status (5)

Country Link
US (1) US2095035A (xx)
BE (1) BE400555A (xx)
FR (1) FR766178A (xx)
GB (1) GB424714A (xx)
NL (1) NL41663C (xx)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2486986A (en) * 1943-06-28 1949-11-01 Rca Corp Permeability tuning system
US2495624A (en) * 1944-03-16 1950-01-24 Hartford Nat Bank & Trust Co Radio receiver with band-spread tunable circuits
US2536331A (en) * 1944-02-15 1951-01-02 Hartford Nat Bank & Trust Co Superheterodyne receiver
US3292089A (en) * 1962-12-31 1966-12-13 Gen Electric Uhf converter circuit arrangement
EP0160331A1 (en) * 1984-04-12 1985-11-06 Koninklijke Philips Electronics N.V. Tuning arrangement

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE446844A (xx) * 1941-08-16

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2486986A (en) * 1943-06-28 1949-11-01 Rca Corp Permeability tuning system
US2536331A (en) * 1944-02-15 1951-01-02 Hartford Nat Bank & Trust Co Superheterodyne receiver
US2495624A (en) * 1944-03-16 1950-01-24 Hartford Nat Bank & Trust Co Radio receiver with band-spread tunable circuits
US3292089A (en) * 1962-12-31 1966-12-13 Gen Electric Uhf converter circuit arrangement
EP0160331A1 (en) * 1984-04-12 1985-11-06 Koninklijke Philips Electronics N.V. Tuning arrangement

Also Published As

Publication number Publication date
NL41663C (xx)
GB424714A (en) 1935-02-27
FR766178A (fr) 1934-06-22
BE400555A (xx)

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