US2606290A - Electronic tuning indicator for radio receivers - Google Patents

Electronic tuning indicator for radio receivers Download PDF

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Publication number
US2606290A
US2606290A US161051A US16105150A US2606290A US 2606290 A US2606290 A US 2606290A US 161051 A US161051 A US 161051A US 16105150 A US16105150 A US 16105150A US 2606290 A US2606290 A US 2606290A
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US
United States
Prior art keywords
voltage
tube
anode
intermediate frequency
indicator
Prior art date
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Expired - Lifetime
Application number
US161051A
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English (en)
Inventor
Johan Hendrik Van Wageningen
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
Original Assignee
Hartford National Bank and Trust 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
Application filed by Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
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Publication of US2606290A publication Critical patent/US2606290A/en
Anticipated expiration legal-status Critical
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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning
    • H03J3/02—Details
    • H03J3/12—Electrically-operated arrangements for indicating correct tuning
    • H03J3/14—Visual indication, e.g. magic eye

Definitions

  • This invention relates to electronic tuning devices used in wireless receivers having automatic volume control. In such apparatus it is frequently diflicult to eflect tuning by ear and for this reason use is frequently made of visual tuning.
  • an electron-ray indicator may be used, which comprises a discharge tube having a cathode and an anode, and one or more deflection electrodes which are subject to a voltage derived from the detector portion of the apparatus and which impart to the electron beam emitted by the cathode a deflection varying with this voltage.
  • the anode is in most cases conical in shape and is internally coated with fluorescent material, the arrangement being such that the anode may be observed from the upper side of the tube.
  • the tube is arranged in the apparatus in such manner that only the upper side is visible from the outside, the tube being preferably arranged behind an aperture provided in the cabinet of the apparatus. Consequently, when the apparatus is in operation, that side of the anode which can be observed from the outside has produced on it fluorescent spots the dimensions of which are a measure of the accuracy of tuning of the apparatus.
  • This amplifying system may comprise a control grid, an anode connected to the deflection electrodes and a cathode, and the latter may be integral with the cathode of the indicator proper.
  • the control grid has supplied to it a control voltage, whilst the anode is connected by way of a coupling resistance to the positive terminal of the high tension supply.
  • the amplification furthermore affords the advantage that the deflection voltage has the polarity which is generally desired.
  • the electron beam is, according to the inventiomnot only amplification of which is controlled as a functiono of the signal voltage.
  • the invention is based on the fact that the width of the fluorescent spot is controlled'by this second voltage only at higher signal strength.
  • the anode of the said amplifying tube is preferably connected through a coupling resistance to the screen grid of a tube controlled inamplification, this screen grid being connected by way of a supply resistance to the positive terminal of the high tension supply.
  • the screen grid of the tube controlled in amplification will have a voltage which increases with increasing signal strength, since the screen grid current decreases with increasing signal strength.
  • the invention is of particular importance for circuit-arrangements in which an electron-ray indicator having two sensitivities is provided. These two sensitivities are usually obtained by utilising two amplifying systems, the control grids of which are interconnected, but of which one control grid, for example due to its being wound with a different pitch, imparts to the associated amplifying tube an amplification factor which is different from that of the other amplifier.
  • the indicator portion comprises two deflection systems, of, which one is subject to' the action of the voltage at the anode of one amplifier and the other to the action of the voltage at the anode of the other amplifier. As a rule, two luminous spots are then visible on the fluorescent screen of the indicator whilst the deflection systemsact upon the width of the shade sectors between these spots.
  • Onesector may serve for tuning to stations the signal strength of which is comparatively small and the other sector for tuning to stations having a greater signal strength.
  • reference numeral I designates the input terminals of an input band-pass filter comprising two circuits 2 and 3 and to which the incoming intermediate frequency oscillations are supplied.
  • Tube 4 is an intermediate frequency amplifying tube having a cathode 5. and a control grid 6 which has supplied to it the intermediate-frequency oscillations.
  • thermore comprises a screen grid 1, which is connected by way of .a resistance 33 to the positive terminal of a source of supply, and a suppressor grid 8, connected to the cathode.
  • the first circuit 9 of a second intermediate frequency filter 9, III! is connected to the anode.
  • a tapping on the coil of the second circuit In is connected to the anode of a detector tube II, the cathode of which is grounded.
  • the detector circuit furthermore comprises two series-connected resistances I2, l3, the second of which has derived from it the low-frequency modulation voltage which is supplied to. terminals Id.
  • the condenser I operates as :a short-circuit for the. intermediateirequency currents.
  • a voltage of intermediate frequency isv derived by way of a condenser H from the circuit 9 and supplied to a diode anode l5- incorporated in the tube 4- diode circuit furthermore comprises a resistance l8, across.
  • a tube 23 having a cathode common to a plurality of electrodesystems andconnected-to-earth For the indication ofv tuning, provision ismade of a tube 23 having a cathode common to a plurality of electrodesystems andconnected-to-earth.
  • the tube comprises two triode amplifiers, the
  • anode is covered inlmownmanner with fiuores cent material and the defiectionelectrodes are-so positionedthat. two luminous spots separated by shade sectors are. seen onthe cathode.
  • the de-- The tube fur- 4 flection electrodes 28 and 29 are connected to the anodes 2B and 21.
  • the voltage set up across resistance I3 is active at the grid 2 5.
  • the operation of the arrangement described is such that if the voltage across resistance I3 increases, for example due to an increase in signal strength as a result of the correct point of tuning being approached, the electron current flowing to the anode 26 decreases so that the voltage at the anode itself increases as a result of the voltage loss across the resistance 3! and one shade sector on the. fluorescent screen of the anode decreases in width. With correct tuning the width of the shade sector is as small as possible.
  • the voltage across resistance I3 is also active at the grid of the second triode the sensitivity of which, however, is much smaller so that the voltage at the second deflection plate 28, upon variation in the voltage across resistance I3, is varied to a much smaller extent and the associated shade sector shows a much smaller decrease in width.
  • the control voltage at the controlgridfi' of the tube 4- has, so high anabsolute value that a high voltage is set up at the screen grid so that a controlling, actionisexerted' upon the shade sector associated with deflection plate 28.
  • the triode 24; 25; 21 may also exert a controlling action-Lin the normalway, although this not alwaysrequiredfor satisfactory operation of the device.
  • the width of the shade sector for the indication at great signal strength. is controlled not only by the variation. in: the anode. current of the. amplifying triode, whichds:
  • a radio receiver provided with an intermediate frequency amplifier including an electron discharge tube having a screen grid electrode and an electrode, a detector coupled to the output of the intermediate frequency amplifier and means to automatically control the volume of said intermediate frequency amplifier in accordance with the detected signal, a tuning indicator for said receiver comprising an electron ray tube having an amplifier section and a cathode-ray indicating section provided with a deflection system and a fluorescent target, means to supply the detected signal to the amplifying section of said electron ray tube, means to derive a control signal from one of the electrodes of the tube in the intermediate frequency amplifier, and means to supply said control signal to said electron ray tube whereby the resultant visual indication of said target is dependent both on said detected signal and said control signal.
  • control signal is derived from the screen grid electrode of the tube in the intermediate frequency amplifier.
  • a radio receiver provided with an intermediate frequency amplifier including an electron discharge tube having a screen grid electrode and an anode electrode, a detector coupled to the output of the intermediate frequency amplifier and means to automatically control the volume of said intermediate frequency amplifier in accordance with the detected signal, a tuning indicator for said receiver comprising an electron ray tube having an amplifier section and a cathode-ray indicating section provided with two deflection elements, an electron beam source and a fluorescent target, means to supply the detected signal through the amplifying section of said electron ray tube to one of said deflection elements to effect beam deflection with respect to-said target for detected signals of low signal strength, means to derive a control signal from one of the electrodes of the tube in the intermediate frequency amplifier, and means to supply said control signal to the other of said deflection elements to effect beam deflection with respect to said target for detected signals of increased signal strength whereby the resultant visual indication of said target is dependent both on said detected signal and said control signal.
  • a radio receiver provided with an intermediate frequency amplifier including an electron discharge tube having a screen grid electrode and an anode electrode, a detector coupled to the output of the intermediate frequency amplifier and means to automatically control the volume of said intermediate frequency amplifier in accordance with the detected signal, a tuning indicator for said receiver comprising an electron ray tube having first and second amplifier sections, the amplification factor of said first amplifier section exceeding that of said second amplifier section, and a cathoderay indicating section provided with two deflection elements and a fluorescent target, means to supply the detected signal through said first amplifying section of said electron ray tube to one of said deflection elements, means to derive a control signal from the screen grid electrode of the tube in the intermediate frequency amplifier, and means to supply said control signal through said second amplifying section of said electron ray tube to the other of said deflection elements whereby the resultant visual indication of said target is dependent both on said detected signal and said control signal.

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  • Circuits Of Receivers In General (AREA)
  • Amplifiers (AREA)
US161051A 1949-06-17 1950-05-10 Electronic tuning indicator for radio receivers Expired - Lifetime US2606290A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL682805X 1949-06-17

Publications (1)

Publication Number Publication Date
US2606290A true US2606290A (en) 1952-08-05

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ID=19805559

Family Applications (1)

Application Number Title Priority Date Filing Date
US161051A Expired - Lifetime US2606290A (en) 1949-06-17 1950-05-10 Electronic tuning indicator for radio receivers

Country Status (4)

Country Link
US (1) US2606290A (sk)
BE (1) BE496379A (sk)
FR (1) FR1020230A (sk)
GB (1) GB682805A (sk)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2828421A (en) * 1953-07-31 1958-03-25 Philips Corp Frequency modulation tuning indicator
US2970212A (en) * 1956-09-27 1961-01-31 Gen Motors Corp Transistorized low voltage receiver

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2190435A (en) * 1936-06-27 1940-02-13 Rca Corp Tuning indicator circuits
US2451584A (en) * 1945-10-27 1948-10-19 Rca Corp Signal receiver tuning indicator
US2457016A (en) * 1945-10-26 1948-12-21 Rca Corp Frequency modulation receiver tuning aid

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2190435A (en) * 1936-06-27 1940-02-13 Rca Corp Tuning indicator circuits
US2457016A (en) * 1945-10-26 1948-12-21 Rca Corp Frequency modulation receiver tuning aid
US2451584A (en) * 1945-10-27 1948-10-19 Rca Corp Signal receiver tuning indicator

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2828421A (en) * 1953-07-31 1958-03-25 Philips Corp Frequency modulation tuning indicator
US2970212A (en) * 1956-09-27 1961-01-31 Gen Motors Corp Transistorized low voltage receiver

Also Published As

Publication number Publication date
FR1020230A (fr) 1953-02-03
GB682805A (en) 1952-11-19
BE496379A (sk)

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