US1820809A - Electrical system - Google Patents

Electrical system Download PDF

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Publication number
US1820809A
US1820809A US178476A US17847627A US1820809A US 1820809 A US1820809 A US 1820809A US 178476 A US178476 A US 178476A US 17847627 A US17847627 A US 17847627A US 1820809 A US1820809 A US 1820809A
Authority
US
United States
Prior art keywords
cathode
circuit
grid
oscillator
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 - Lifetime
Application number
US178476A
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English (en)
Inventor
Edward W Kellogg
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.)
General Electric Co
Original Assignee
General Electric Co
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 NL25668D priority Critical patent/NL25668C/xx
Priority to US20114D priority patent/USRE20114E/en
Application filed by General Electric Co filed Critical General Electric Co
Priority to US178476A priority patent/US1820809A/en
Priority to DEI33909D priority patent/DE510108C/de
Priority to FR654193D priority patent/FR654193A/fr
Application granted granted Critical
Publication of US1820809A publication Critical patent/US1820809A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B15/00—Suppression or limitation of noise or interference
    • H04B15/02—Reducing interference from electric apparatus by means located at or near the interfering apparatus
    • H04B15/04—Reducing interference from electric apparatus by means located at or near the interfering apparatus the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder
    • H04B15/06—Reducing interference from electric apparatus by means located at or near the interfering apparatus the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder by local oscillators of receivers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D7/00—Transference of modulation from one carrier to another, e.g. frequency-changing
    • H03D7/06—Transference of modulation from one carrier to another, e.g. frequency-changing by means of discharge tubes having more than two electrodes
    • H03D7/08—Transference of modulation from one carrier to another, e.g. frequency-changing by means of discharge tubes having more than two electrodes the signals to be mixed being applied between the same two electrodes

Definitions

  • My invention relates to electrical systems comprising a space discharge device having its input circuit connected to an antenna through a local high frequency source, and
  • heterodyne systems comprising an antenna and a local source or oscillator operated at a frequency slightly different from that of the antenna for producing a low frequency beat voltage
  • the local source or oscillator incidentally impresses a voltage across the antenna tuning.
  • the oscillator voltage is in fact divided between the two circuit elements, antenna tuning and grid to cathode capacity, and the fraction of the oscillator voltage which is impressed across the antenna tuning depends on the impedance drops through two different parts of the circuit.
  • the grid to cathode capacity reactance is of the order of 10,000
  • the impedance of the tuned antenna circuit varies from a few hundred ohms when the oscillator is operated at a frequency substantially dilferentfrom that for which the antenna is tuned to from 10,000 to 40,000 ohms when the oscillator frequency is substantially the same as that for which the antenna is tuned.
  • the frequency of the oscillator is substantially different from that for which the antenna is tuned, there is little variation in the antenna voltage produced by adjustment in the frequency of theoscillator.
  • the frequency of the oscillator frequently crosses that for which the antenna is tuned and the antenna voltage is varied in a manner to interfere with other receiving sets.
  • this difnassueo ficulty is avoided by connecting the oscillator to the input circuit in such a waythat the potential of the grid with respect to ground I (assuming one end of the antennatuning coil' to be grounded) is substantially unaffected by the oscillator voltage, while the necessary a cathode to grid voltage is obtained by causing the cathode to vary in potential with re-,
  • Fig. 1 diagram:
  • matioally illustrates a heterodyne system wherein my invention has been embodied; and Figs. 2 and 3 illustrate its application to slightly different autodyne systems.
  • Fig. 1 shows a detector devicel which is provided with an input circuit comprising a grid 2, a cathode 3, a double-wire secondary' winding 40f a transformer 5, and a tunin element 6 connected between an antenna f -er 9 and a transformer winding 10, and an anode 11.
  • A, local source of oscillations or oscillator 12 is connected to the input circuit of the device 1 through a primary winding 13 and the secondary winding 4 each turn of which is made of double wire in order to permit the transmission of heating current to the anode 3 froma source 14 through a control resistor 15.
  • a winding 16, inductively related to the winding 13, is connected to the grid 2 or high potential end of the input circuit through a condenser 17 for the purpose of neutralizing the effect of the capacity couplixnlg between the grid 2 and the cathode 3.
  • the oscillator 12 causes the potential of the cathode 3 to change with respect to ground or low potential end of the input circuit but produces little, if any, effect on the potential of the grid 2. Since the anode 11 is virtually grounded through "the" intermediate frequency tuning -condenser 9, there is no tendency for currents of oscillator'frequency to get into the antenna circuit by way of'th'e grid to anode capacity. J The potential of the antenna 7 with i' respect to ground is thus substantially un zifiectedby the oscillator and interference with-other receivingis avoided.
  • Fig; 2 illustratesfan autodyne system wherein a' resistor 18 is connected in the oscillator circuit topermit adjustment in in- Y tensity of'the'oscillations.
  • V In the case of the "autodyn'e' circuit, an appreciable impedjprevious' case. Under these conditions the balancing condenser 17 would need to be reance at oscillator frequency is introduced by the feed back coil in the anode circuit, and 'thereforethe anode is no longer maintained at practically stationary potential as in the adjusted in orderfthat it might balance out the electrostatic effect on the grid. of both cathode'and anode capacities. If the cou- 'pling'beti'veen coil '5 and coils 4 and 16 can be maintained constant, theratio between cathode'and anode voltages at oscillation. frequency will remain substantially constant,
  • the rheostat 18 provides means whereby the amount of feed back can be con- 'trolledwithout 'changing'the coupling between coil 13-and coils4'and16. It should be bornein mind in following this discussion that the output circuit 9,10, istuned for a frequency which differs-widely from the os cillation frequencyand has negligible impedance for 1 the oscillation currents.
  • the oscillator-tuned circuit maybe connected in series with themtermediate tuning condenser 9' as shown 1n Fig. 3.
  • circuit 6-7 which is represented as an antenna, mightinstead, be a receiving loop,
  • a radio apparatus of the heterodyne type including a detector tube, an input circuit for said-tube having a low potential end connected with the cathode of the tube for impressing a signal voltage upon said tube, an output circuit'tor said tube,.means providing a common grounded connection between said output circuit and said low potential endof said input circuit, a source of oscillations, and means coupled with said source and'interposed in'circuitbetween the low potential end of the input circuit and said cathode for causing the cathode potential to varywith respect to'the low potential end of said input 'circuit.
  • a radio apparatus of the heterodync type including a detector tube, an input circuit for said tube having a low potential end connected with the cathode of the tube for impressing a signal voltage upon said tube,
  • an output circuit for said tube means providing a common grounded connection between. said output circuit and said low potential end of said inputcircuit, a source of oscillations, means coupled with said source and interposed in circuit between the low potential end of the input circuit and said ing a grid, a cathode and an anode, and a tuned'mput circuit connected between said grid and cathode, of means for impressing the oscillations of said source upon said device without radiating the same from said tuned circuit, including a ground connec tion for said'input circuit, a transformer having a primary winding connected with.- said source and a secondary winding 1nter-.
  • the combination withan'electric discharge device having a grid, an anode and a cathode, of a ground connection, an input signal voltage circuit for said device connected between the ground connection and the grid of said device, an
  • an electric discharge device having a grid, an anode aniid a cathode, of a ground connection, aniiiput signal voltage circuit for said device connected between the ground connection and the grid of said device, an output circuit connected between the ground connection and the anode, means for applying an oscillation voltage between the ground connection and the cathode, and means connected between the ground connection and the grid of said device for neutralizing the connected between the ground connection and the anode, means for applying an oscillation voltage at a different frequency from the signal voltage between the ground connection and the cathode, and means for tuning said input and output circuits.
  • an electric discharge device having a grid, an anode and a cathode, of a ground connection, an input signal voltage circuit for said device connected between the ground connection and the grid of said device, an output circuit connected between the ground connection and the anode, and meansjor applying an oscillation voltage between the ground connection and the cathode, and
  • means for adjusting the intensitv of the oscillation voltage applied from said source means for adjusting the intensitv of the oscillation voltage applied from said source.
  • the method of heterodvning a radio signal which comprises applying asignal voltage at a certain frequency between the grid of an electric discharge device and ground, and simultaneously applying an oscillation voltage at a different frequency between ground and the cathode of said device.
  • the method of heterodyning a radio signal which comprises applying a signal voltage at a certain frequency between the grid of an electric discharge device and ground, neutralizing the inter-e1ectrode capacity of the device, and simultaneously applying an oscillation voltage at a different frequency between ground and the cathode of said device.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Optical Communication System (AREA)
  • Superheterodyne Receivers (AREA)
US178476A 1927-03-25 1927-03-25 Electrical system Expired - Lifetime US1820809A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL25668D NL25668C (xx) 1927-03-25
US20114D USRE20114E (en) 1927-03-25 Electrical system
US178476A US1820809A (en) 1927-03-25 1927-03-25 Electrical system
DEI33909D DE510108C (de) 1927-03-25 1928-03-23 Verfahren zur Vermeidung der Ausstrahlung der oertlich erzeugten Hochfrequenzschwingungen bei UEberlagerungsempfaengern
FR654193D FR654193A (fr) 1927-03-25 1928-03-24 Perfectionnements aux systèmes électriques comportant des tubes à décharge électronique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US178476A US1820809A (en) 1927-03-25 1927-03-25 Electrical system

Publications (1)

Publication Number Publication Date
US1820809A true US1820809A (en) 1931-08-25

Family

ID=22652687

Family Applications (1)

Application Number Title Priority Date Filing Date
US178476A Expired - Lifetime US1820809A (en) 1927-03-25 1927-03-25 Electrical system

Country Status (4)

Country Link
US (1) US1820809A (xx)
DE (1) DE510108C (xx)
FR (1) FR654193A (xx)
NL (1) NL25668C (xx)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE739095C (de) * 1932-04-16 1944-01-19 Opta Radio Ag Mischroehrenschaltung fuer UEberlagerungsempfaenger
NL89165C (xx) * 1949-02-16
DE967593C (de) * 1953-12-25 1957-11-28 Max Braun Fa Additive Trioden-Mischstufe fuer sehr hohe Frequenzen
DE1013332B (de) * 1956-05-18 1957-08-08 Telefunken Gmbh Neutralisierungsschaltung fuer eine selbstschwingende Mischstufe, z.B. in Fernsehempfaengern mit Kanalschalter
DE1022272B (de) * 1956-12-19 1958-01-09 Telefunken Gmbh Selbstschwingende Mischstufe mit Triode fuer hohe Frequenzen, insbesondere fuer die Fernsehbaender auf dem Dezimeterwellen-Gebiet

Also Published As

Publication number Publication date
FR654193A (fr) 1929-04-03
DE510108C (de) 1930-10-16
NL25668C (xx)

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