FR400082A - Secret telephone transmitter - Google Patents

Secret telephone transmitter

Info

Publication number
FR400082A
FR400082A FR400082A FR400082DA FR400082A FR 400082 A FR400082 A FR 400082A FR 400082 A FR400082 A FR 400082A FR 400082D A FR400082D A FR 400082DA FR 400082 A FR400082 A FR 400082A
Authority
FR
France
Prior art keywords
telephone transmitter
secret telephone
secret
transmitter
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
FR400082A
Other languages
French (fr)
Inventor
Lawrence Heyworth
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.)
LAWRENCE HEYWORTH
Original Assignee
LAWRENCE HEYWORTH
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 LAWRENCE HEYWORTH filed Critical LAWRENCE HEYWORTH
Application granted granted Critical
Publication of FR400082A publication Critical patent/FR400082A/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
    • H04M1/02—Constructional features of telephone sets
    • H04M1/19—Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Telephone Set Structure (AREA)
FR400082A 1909-03-02 1909-03-02 Secret telephone transmitter Expired FR400082A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB190905114T 1909-03-02

Publications (1)

Publication Number Publication Date
FR400082A true FR400082A (en) 1909-07-17

Family

ID=32490595

Family Applications (1)

Application Number Title Priority Date Filing Date
FR400082A Expired FR400082A (en) 1909-03-02 1909-03-02 Secret telephone transmitter

Country Status (2)

Country Link
FR (1) FR400082A (en)
GB (1) GB190905114A (en)

Also Published As

Publication number Publication date
GB190905114A (en) 1910-03-02

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