US1603319A - Telephone repeater - Google Patents

Telephone repeater Download PDF

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Publication number
US1603319A
US1603319A US314547A US31454719A US1603319A US 1603319 A US1603319 A US 1603319A US 314547 A US314547 A US 314547A US 31454719 A US31454719 A US 31454719A US 1603319 A US1603319 A US 1603319A
Authority
US
United States
Prior art keywords
line
repeater
circuit
filter
impedance
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
US314547A
Other languages
English (en)
Inventor
Alva B Clark
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.)
AT&T Corp
Original Assignee
American Telephone and Telegraph Co Inc
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 NL10539D priority Critical patent/NL10539C/xx
Application filed by American Telephone and Telegraph Co Inc filed Critical American Telephone and Telegraph Co Inc
Priority to US314547A priority patent/US1603319A/en
Priority to GB21684/20A priority patent/GB149331A/en
Priority to DEB95257D priority patent/DE454207C/de
Priority to FR521218A priority patent/FR521218A/fr
Application granted granted Critical
Publication of US1603319A publication Critical patent/US1603319A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40—Circuits
    • H04B1/54—Circuits using the same frequency for two directions of communication
    • H04B1/58—Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/36—Repeater circuits

Definitions

  • This invention vre'lates to vtelephone, repeeters; more particularly it concernsiarrangements of circuits land apparatus for preventing repeater singing.
  • a repeater. is therefore apt to singiat the high frequencies and itis customary to associate with thefrepeater a filter which serves to attenuate and approximately extinguish currents abov e i say 2200 cycles, lwhile it vtransmits with4 practically negligible'loss frequencies below this range.
  • this filter is associated with the input circuit where it suppresses the high frequencies before they reach the amplifying device.
  • This arrangement is open to certain objections explained hereinafter and thejessence of the present invention is to provide a4 new and improved arrangement of the repeater apparatus in which. arrangement a filter is associated with the amplifying device in its output circuit.
  • Figure l is a diagrammatic Aview showing an arrangement lot apparatus and circuits embodying this invention associatedwith "a well known .type of one-element. repeater, Fig. 2l being a diagrammaticjview similar to Fig. l, showing-the arrangement of this invention associated with a well known type of two-element repeater.
  • yreference character L designates a telephone iine across which is bridged a, potentiometer 2 having associated therewith in variable" relationship the input transformer 8 of an amplifying'device which is f here shown. as an 4electron tube 4.
  • This tube is provided with the usual filamenQ- ⁇ plate and grid, supplied with current and vpotential .by the batteries A, B andyC,
  • the output circuit' of 4the tube is led through a filter F to the output transformer l0, the secondary wind!v ings of which transformer are inserted in series with the line conductors and arranged symmetrically with respect to' the points at which the potentiometer 2 is connected tothe line.
  • the sections oftheline L extending to the left and to the right'of the repeater are balanced for currents of voice frequencies in order to prevent singing of the repeaters' at these frequencies.
  • the i filter suppresses currents of aj frequency higher. than 2200 cycles, and for frequencies belowfthis range substantiallyvno potential difference between the herminals'of the ypo-,fv tentiometer is produced by the electro-r ⁇ nonr tive force impressed on the line conductors by transformer 1Q, because .of .the balance of the line. Singing ofthe repeater atthe higher frequencies is. thus prevented by the filter, whereas'at the lower frequencies is effectively precluded, when the tube 1s operating -with Anormal amplification, bythe line.
  • vthe vtiltery may be arranged to' attenuate also currents of low frequency, permitting only such currents to pass as are necessary for the transmission of intelligible speech.
  • ⁇ f The range of frequencies at which ak filter is effective is determined by 'th'e impedances of its elements, vand reference may be-had to the patent of G. A. Campbell, 1,227,114, May
  • the said' filter is in conductive connection with vthe line wires.
  • cach series impedance of the ilter conduc tively connected in one Wire must be balanced by a like impedance connected in the other.
  • Each series inductance coil of the ilter is therefore in practice provided with two windings, one in cach and for pericct balance these windings must be alike in every respect.
  • the ilter of the present "arrangement isv associated with the output circuit o the electron tube.
  • This circuit has no conductive connection with the line and need therefore not be balanced,
  • the inductance coils oi.' other impedance of the filter serially connected into one conductor of the circuit need therefore not be balanced by like coils or otlierimpedanccs in the other conductor Moreover,- since for any cutoi frequency the iinpedances of the elements 'of a filter are determined by the impedance of the circuit into which the filter is con nected, itis readily understood that whenv a filter is conductively associated 'uiith a transmission line its impedances must be calculated relative to the impedance of the line, a filter ot different impedance relations beingr necessary for each diii'crentrline.
  • the impedance oit the filter is determined by the impedance of the output circuit of the amplifying device, which impedance ,is readily determinable and does not vary with each line: The adjustment of the filter .im-
  • the grid is substantially an insulated charged body except for its connection to the external circuit.
  • the impedance of the input orgrid circuit of the electron tube is therefore extremely high, being principally the reactance due tothe electrostatic capacity of the grid to its surroundings. Furtlien more, to obtain an adequate output oiienergy from the electron 'tube a voltage must be impressed upon its grid which is high in comparison 'with those usually lexisting in telephone circuits,
  • ncoasie and costhaving a suciently high self-in-v ductance 'for satisfactory performance at low frequency has so much capacity in its windings as to be unsatisfactory athigh in quencies.
  • the best available compromise design. has lower sel'-in'ductance in proportion to the impedance with which it Works lthan is the case 'with other transformers in the, repeater circuit, and in addition the ef feats of capacity are great enough to be injurious,
  • the internal capacity of the input transformer together with the capacity of the grid and connecting Wires causes imn pedance effects at high frequencies and the relatively low lself inductance causes infr pcdance effects at low frequencies that are all unfavorable to the correct functioning of the filter when the same is connected, as heretofore., into the input circuit of the tube.
  • the output cirn cuit removes it from theiniuencc of the input transformer thus improving its be liavior and in turnl improving; the charac teristics of the whole repeater set.
  • the efficiency of the input transformer is reduced at low frequencies by any impedance in series between it and the line. 'Acsociating the filter with the output circuit of the electron tube thus improves the behavior of the input impedance.
  • An amplifying device herein shown as an electron tube 4, is provided for each portion of thelne and associated therewith by a potcntioinetcr and a transformer .18, the output circuit of each tube being, associated with fthe'- portion of the line opposite. thereto by means oi an output transformer 10.
  • a lter F is inserted into the outputleircuit of each tube, similarly as in Fig.
  • the potentiometer 2 is provided two adjustable contacts and that these are shown substantially at equal distances from the ends of the-Winding.
  • the potentiometer 2 stands in balanced relation to the two sides of the of the potentiometer may be made by moving the equal amounts oppositely so as to the balanced relation line L.
  • Vtrimsmission line having its two sides in balanced relation, a vacuum tube amplifying device, a circuit inductively associating one side of said device with said line, and a wave iilter in said circuit, said 'Wave ilter'co'mprisin an impedance device in unbalanced re ation to' .the two sides of the is comprised.
  • a transmission line of such length as to be subject to considerable ⁇ attenuation and external interference a repeuter therefor comprising an electron tube am lifying device having an output circuitl of igli impedance relative to the impedance for associatin said circuit with said line and a filter in sai with and having certain elements in unbalanced ⁇ relation to the sides of said circuit.
  • repeater comprising an amplifying element, said repeater also comprising apparatus con- .nected with the line by a pair or conductors, said apparatus being in unbalanced relation to said pair of conductors ,and said apparatus being. placed on the output side of tbe amplifying element of the repeaters f 7
  • repeater comprising apparatus in unbalanced. relation to the two sides of the line, said apparatus being placed on the output side of tbe repeater, and. a balanced potentiometer connecting the repeater with the 'tine on tbe input side.
  • a transmission li ne having its two sides in balanced relation and a repeater comprising a one-way amplifying element, said element having itsinput side connected with the line by means of a balanced potentiometer.
  • a repeater and a transmission line comprisingv a three-electrode vacuum tube and a baianced potentiometer, the said vacuum tube having its input side connected through said poten-- tiometer with said line.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Amplifiers (AREA)
US314547A 1919-07-31 1919-07-31 Telephone repeater Expired - Lifetime US1603319A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL10539D NL10539C (de) 1919-07-31
US314547A US1603319A (en) 1919-07-31 1919-07-31 Telephone repeater
GB21684/20A GB149331A (en) 1919-07-31 1920-07-19 Telephone repeating circuit
DEB95257D DE454207C (de) 1919-07-31 1920-07-25 Telephon-Verstaerkeranordnung mit Ausgleichsuebertragern und gegebenenfalls Leitungsnachbildungen
FR521218A FR521218A (fr) 1919-07-31 1920-07-27 Perfectionnements dans les circuits téléphoniques utilisant des répéteurs électriques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US314547A US1603319A (en) 1919-07-31 1919-07-31 Telephone repeater

Publications (1)

Publication Number Publication Date
US1603319A true US1603319A (en) 1926-10-19

Family

ID=23220384

Family Applications (1)

Application Number Title Priority Date Filing Date
US314547A Expired - Lifetime US1603319A (en) 1919-07-31 1919-07-31 Telephone repeater

Country Status (5)

Country Link
US (1) US1603319A (de)
DE (1) DE454207C (de)
FR (1) FR521218A (de)
GB (1) GB149331A (de)
NL (1) NL10539C (de)

Also Published As

Publication number Publication date
NL10539C (de)
GB149331A (en) 1921-09-22
FR521218A (fr) 1921-07-08
DE454207C (de) 1928-01-03

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