FR464394A - Improvements to telephone installations - Google Patents

Improvements to telephone installations

Info

Publication number
FR464394A
FR464394A FR464394DA FR464394A FR 464394 A FR464394 A FR 464394A FR 464394D A FR464394D A FR 464394DA FR 464394 A FR464394 A FR 464394A
Authority
FR
France
Prior art keywords
telephone installations
installations
telephone
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
Other languages
French (fr)
Inventor
Arthur F Erickson
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.)
ARTHUR F ERICKSON
Original Assignee
ARTHUR F ERICKSON
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 ARTHUR F ERICKSON filed Critical ARTHUR F ERICKSON
Application granted granted Critical
Publication of FR464394A publication Critical patent/FR464394A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/68—Circuit arrangements for preventing eavesdropping
    • H04M1/70—Lock-out or secrecy arrangements in party-line systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
FR464394D 1913-11-04 1913-11-04 Improvements to telephone installations Expired FR464394A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR464394T 1913-11-04

Publications (1)

Publication Number Publication Date
FR464394A true FR464394A (en) 1914-03-19

Family

ID=1503368

Family Applications (1)

Application Number Title Priority Date Filing Date
FR464394D Expired FR464394A (en) 1913-11-04 1913-11-04 Improvements to telephone installations

Country Status (1)

Country Link
FR (1) FR464394A (en)

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