GB352097A - Electric communication transmission system employing filters - Google Patents

Electric communication transmission system employing filters

Info

Publication number
GB352097A
GB352097A GB1130330A GB1130330A GB352097A GB 352097 A GB352097 A GB 352097A GB 1130330 A GB1130330 A GB 1130330A GB 1130330 A GB1130330 A GB 1130330A GB 352097 A GB352097 A GB 352097A
Authority
GB
United Kingdom
Prior art keywords
cable
filter
receiving
filters
common
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
Application number
GB1130330A
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.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
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 Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB1130330A priority Critical patent/GB352097A/en
Publication of GB352097A publication Critical patent/GB352097A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
    • H04M11/062—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors using different frequency bands for speech and other data

Abstract

352,097. Two-way terminal equipment. STANDARD TELEPHONES & CABLES, Ltd. and SANDEMAN, E. K., Columbia House, Aldwych, London. April 9, 1930, No. 11303. [Class 40 (iv).] In a cable system in which the transmitting and receiving circuits are connected to the cable over filters, a common filter is provided in addition to filters individual to the receiving and transmitting branches. The impedance of the transmitting and common filters is matched to that of the cable whilst the receiving filter presents a high impedance to currents received over the cable or alternatively all the filters can be matched to the cable, the receiving amplifier being adjusted to introduce large reflection. In the former case air-cored inductance coils are used in the transmitting and common filters whilst cores of magnetic material are used in the receiving filter. A telegraph channel may be connected to the cable. In the Figure the transmitted signals are connected through amplifier T1, transmission filter F3 and common filter F1 to the cable C whilst received signals pass to the receiving circuit through common filter F1, receiving filter F4 and receiving amplifier R1. The telegraph apparatus TG is connected via filter F5. The filter F4, which may comprise inductance coils having cores of compressed magnetic dust, offers a high impedance to the cable and thus steps up the received voltage. The impedance of amplifier R1 is matched to F4 thus reducing the noise caused by thermal agitation in the cable.
GB1130330A 1930-04-09 1930-04-09 Electric communication transmission system employing filters Expired GB352097A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1130330A GB352097A (en) 1930-04-09 1930-04-09 Electric communication transmission system employing filters

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1130330A GB352097A (en) 1930-04-09 1930-04-09 Electric communication transmission system employing filters

Publications (1)

Publication Number Publication Date
GB352097A true GB352097A (en) 1931-07-09

Family

ID=9983751

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1130330A Expired GB352097A (en) 1930-04-09 1930-04-09 Electric communication transmission system employing filters

Country Status (1)

Country Link
GB (1) GB352097A (en)

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