US2207886A - Noise reduction circuit - Google Patents

Noise reduction circuit Download PDF

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Publication number
US2207886A
US2207886A US212426A US21242638A US2207886A US 2207886 A US2207886 A US 2207886A US 212426 A US212426 A US 212426A US 21242638 A US21242638 A US 21242638A US 2207886 A US2207886 A US 2207886A
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US
United States
Prior art keywords
tube
collector
antenna
input
input circuit
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
US212426A
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English (en)
Inventor
Johannesson Benno
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.)
Telefunken AG
Original Assignee
Telefunken AG
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 Telefunken AG filed Critical Telefunken AG
Application granted granted Critical
Publication of US2207886A publication Critical patent/US2207886A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • H04B1/1009—Placing the antenna at a place where the noise level is low and using a noise-free transmission line between the antenna and the 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
    • H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
    • H04B1/12—Neutralising, balancing, or compensation arrangements

Definitions

  • the oscillations received by the auxiliary antenna are applied to the control grid of an additional amplifier tube whose output electrode is connected in common with the main antenna to the input of the receiver.
  • the advantage of the present invention resides in the fact that the oscillations of the antenna and the compensation oscillations, whose phase is reversed by the additional tube, act at the same time upon the same load, namely upon the input impedance of the receiver, for instance upon the antenna coil, so that a compensation is possible which is independent of the frequency.
  • the first tube of the actual receiver since this tube can be coupled, as is customary, to the antenna coil across a tuned circuit.
  • the arrangement can be employed in a receiver of customary construction without changes in the receiver proper.
  • FIG. 1 shows an example of construction according to the invention.
  • A represents the main antenna of the receiver which is connected to the antenna coil L through an ohmic resistor R, the other end of said coil being grounded.
  • the antenna coil is coupled in the usual manner with the tuned oscillatory circuit K which is placed at the grid of the first tube of the receiver.
  • the auxiliary antenna H disposed in parallel to the lead-in wire, is grounded through the resistor of a high ohmic voltage divider P.
  • the voltage derived at the sliding contact of this voltage divider is applied to the control grid of the additional tube Z, the anode of which is connected to the receiver input by the condenser Ca.
  • the direct current plate potential is supplied through the high ohmic load resistor Ra.
  • VH is the E. M. F. induced in the auxiliary antenna due toa nearby disturbance whereby the said E. M. F. is assumed also to act essentially at the resistor of the voltage divider P, and if a is the proportion of the division of the voltage divider P, while D is the through-grip (reciprocal of amplification factor) of the tube Z, then a substitution scheme can be set up for the present arrangement in which a voltage source having the voltage acts upon the antenna coil across the inner resistance R1 of the tube Z and across the condenser Ca.
  • a radio receiver having a resonant input circuit tuned to a desired signal carrier frequency, a signal collector, a connectionincluding a resistor Between said collector and said input circuit, means ior substantially reducing the efiect of undesi; dnoise-impulses existifig 'ih th'evicinity(if said collector upon said input circuit, said means comprising an auxiliary signal.collectordlocated in close proximity to said first collector, an electron discharge tube provided with input and output electrodes, an aperiodic coupling means including an adjustable resistor connecting the input electrodes of said tube to said auxiliary collector, and an untuned capacity coupling element connecting the output electrodes of said tube to said resonant input circuit.
  • a radio receiver having a resonant input circuit tuned to a desired signal carried frequency, , a signal collector, a lead-in connection including a resistor between said collector and said input circuit, means for substantially reducing the effect of undesired noise impulses existing in the vicinity of said collector upon said input circuit, said means comprising an auxiliary signal collector located in close proximity to, and in parallel with, the lead-in connection to said first collector, an electron discharge tube provided with input and output electrodes, an aperiodic coupling means including a resistive potentiometer connecting the input electrodes of said tube to said auxiliary collector, and an untuned capacity coupling element connecting the output electrodes of said tube to said resonant input circuit.
  • a radio receiver having a resonant input circuit tuned to a desired signal carrier frequency; a signal collector, a connection between said collector and said input circuit, means for substantially reducing the effect of undesired noise impulses existing in the vicinity of said collector upon said input circuit, said means comprising an auxiliary signal collector located in close proximity to said first collector, an electron discharge tube provided with input and output electrodes, an aperiodic coupling means connecting the input electrodes of said tube to said auxiliary collector, and an untuned capacity coupling element connecting the output electrodes of said tube to said resonant input circuit, said connection to said input circuit comprising in series a resistor and a coil, said coil l eing magnetically coupled to said input circuit. 5 ⁇ 4.
  • a signal collectjnga co nection including a resistive impedance between said collector and said input circuit, means for substantially reducing the eiiect oi undesiredngisejmpulses existing in the vicinityof said collector upon said input circuit, saidmeans comprising an auxiliary signal collector located inclos'l'pffoximity to said first collectpr an electron, discharge tu e provided hinpi tand Qutnntelec r d s, an aperiodic coupling means connecting the input electrodes of said tube to said auxib iary collector, an untuned capacityicogpling element connecting the output electrodes of said tube to said resonant input circuit, said aperiodic coupling means consisting of a resistor connected to the auxiliary collector, and meansfor adjl stably connecting said input electrodes to said resistor.
  • a radio signal receiving system of the type having an input tube provided with a tunable signal input circuit, a main antenna, a connection from the antenna to the input circuit comprising the series arrangement of a lead-in, a resistor and a coil, the coil being coupled to the input circuit, an auxiliary antenna located in parallel to said lead-in, a second tube having at least a cathode, a grid and plate, a second resistor connecting said auxiliary antenna to said cathode, means adjustably connecting the grid to said second resistor, and solely a condenser coupling the plate of said second tube to the said coil.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
US212426A 1937-06-24 1938-06-08 Noise reduction circuit Expired - Lifetime US2207886A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2207886X 1937-06-24

Publications (1)

Publication Number Publication Date
US2207886A true US2207886A (en) 1940-07-16

Family

ID=7990119

Family Applications (1)

Application Number Title Priority Date Filing Date
US212426A Expired - Lifetime US2207886A (en) 1937-06-24 1938-06-08 Noise reduction circuit

Country Status (2)

Country Link
US (1) US2207886A (fr)
FR (1) FR839552A (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE971913C (de) * 1948-10-02 1959-04-16 Elektronik G M B H Deutsche Verfahren und Anordnung zum Abgleich von symmetrisch ausgebildeten Antennenanordnungen

Also Published As

Publication number Publication date
FR839552A (fr) 1939-04-06

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