US1495926A - Submarine and long-distance telephone system and method of operating the same - Google Patents

Submarine and long-distance telephone system and method of operating the same Download PDF

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Publication number
US1495926A
US1495926A US573671A US57367122A US1495926A US 1495926 A US1495926 A US 1495926A US 573671 A US573671 A US 573671A US 57367122 A US57367122 A US 57367122A US 1495926 A US1495926 A US 1495926A
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US
United States
Prior art keywords
line
frequency
long
subscribers
cable
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Expired - Lifetime
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US573671A
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English (en)
Inventor
Rellstab Ludwig
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.)
DE NL THERMO TELEPHOON MIJ NV
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DE NL THERMO TELEPHOON MIJ NV
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Application filed by DE NL THERMO TELEPHOON MIJ NV filed Critical DE NL THERMO TELEPHOON MIJ NV
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Publication of US1495926A publication Critical patent/US1495926A/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/36—Repeater circuits
    • H04B3/38—Repeater circuits for signals in two different frequency ranges transmitted in opposite directions over the same transmission path

Definitions

  • My invention relates to improvements in submarine and long-distance telephone systems and the method of operating the same.
  • intensifiers or amplifiers can be provided only at the terminals of the cable, and they can not be mounted within the cable itself, because they require a continuous supply of energy and supervision.
  • Pupin c0118 the cost of the cable is increased and in addition the cables are more rapidly worn out, the said coils being disposed internally of the covering ofthe cable. For these reasons Pupin coils have been provided in submarine cables only in exceptional cases.
  • the object of the improvements is to ob- NETHERLANDS.
  • the subscribers line 7 is compensated by a subsidiary circuit m, and a setof coils n, 0, 0' is connected between the subscribers line f and the subsidiary line 122.
  • the function of the said coils is known to those skilled in the art, the coils o-0" being opposite in effect with respect to their common secondary 0 as regards currents generated in coil 91., but cumulative as regards currents through the line) originating at station A. I v
  • the differentially connected transformers 0, 0' act through secondary 0 on a lowfrequency intensifier or amplifier y of high amplifying power and high energy discharge, the energy of which is used for overcoming the impedance of the cable line.
  • the long distance cable ;0 is compensated at both terminals by subsidiary balancing circuits q and 1- as is known in the art.
  • differentially connected groups of coils s, t, t and u, v, a respectively are provided;
  • the alternating currents from the speaking subscribers microphone at station A, amplified as described at y flow through the cable ;0 in the form of low frequency currents, and they pass through the transformers 4), 0, the secondary voltages of which are added to each other, and so are repeated into the high-frequency generator and amplifier w, which intensifies the oscillations and produces a high-frequency alternating carrier current the frequency of which is far above the frequency of acoustic oscillations.
  • the said high-frequency current is modulated to oscillate with reference to its amplitude at the rate of the currents from the'speaking subscribers station, and in this form it is transmitted to and throu%h the line as of the receiving subscriber, which is connected in the same way as the line 7 of the transmitting subscriber.
  • the high-frequency current acts, by means of the transformers z and h, on the thermic tele' phone is andca-uses therein the reproduction of the sounds, the thermic telephone having the property of transforminga modulated high-frequency current into low-frequency acoustic oscillations.
  • voice waves originating at the transmitter c at station B will be propagated in the same manner through line :0, the low frequency amplifier 3 at terminal CO and the cable p to the terminal ofiice' CO, where through coils t, t, (cumulative in effect for cable currents) they will be repeated into the high frequency generatormodulator-amplifier unit and will thence be transmitted as modulations on a high frequency carrier current through the subscribersline f to the station A, where they will affect the thermic receiving telephone.
  • a two way system is provided, in which currents are transmitted in each direction through successive links or sections (land line-cableland line) at different frequencies, opposite currents in either land line, i. e. currents for sending and for receiving respectively, being of difierent and separable frequencies, and .all currents through the cable '(or equivalent long distance line) being of low or voice frequency, but great power.
  • a condenser 2 of a capacity of microfarad is connected in shunt across the low-frequency intensifier 3 which does not materially reduce the low-frequency ourrents, it representing as against such cur- I rents a high resistance of. about 1000 ohms, while as against-high-frequency currents it acts as a short-circuit of 10 ohms.
  • peating coils differentially connected as between each land line or end link and the respective low frequency amplifiers and high frequency generators and intensifier-s, and as between the same and the ends of the trunk line, whereby low frequency and high frequency currents are kept separate, and low frequency current will not be repeated back into the originating line, nor high frequency currents back into the trunk.
  • inductive terminal connections are repeating coils differentially connected as between each end link and the respective low frequency amplifiers and high frequency generators and intensifiers, and as between the same and the ends of the trunk line, with a low capacity condenser connected in shunt of the repeating coil winding on the input side of the low frequency amplifier to short circuit high frequency currents that pass through said repeating coil.
  • a telephone system comprising a cable with terminal ofiices containing the terminals of subscribers lines, a low frequency ampli-' bomb connected for input, and a high frequency generator, modulator and amplifier unit connected for output, at each end of the cable, a subscribers line terminating at each of said central stations, a subscribers station on each line, having a microphone transmitter and a high frequency receiver, a

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)
US573671A 1923-03-09 1922-07-08 Submarine and long-distance telephone system and method of operating the same Expired - Lifetime US1495926A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL23927A NL12796C (fr) 1923-03-09 1923-03-09

Publications (1)

Publication Number Publication Date
US1495926A true US1495926A (en) 1924-05-27

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ID=9817643

Family Applications (1)

Application Number Title Priority Date Filing Date
US573671A Expired - Lifetime US1495926A (en) 1923-03-09 1922-07-08 Submarine and long-distance telephone system and method of operating the same

Country Status (5)

Country Link
US (1) US1495926A (fr)
DE (1) DE385064C (fr)
FR (1) FR564129A (fr)
GB (1) GB204270A (fr)
NL (1) NL12796C (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE767662C (de) * 1936-06-20 1953-03-16 Lorenz C Ag Verfahren zur Nachrichtenuebermittlung an Teilnehmer, die ueber Zweidrahtleitungen an Vermittlungsstellen angeschlossen sind, die untereinander mittels Vierdrahtleitungen verbunden sind

Also Published As

Publication number Publication date
NL12796C (fr) 1925-03-16
GB204270A (en) 1923-09-27
FR564129A (fr) 1923-12-21
DE385064C (de) 1923-03-18

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