FR370455A - Dispositif assurant le secret des communications téléphoniques - Google Patents

Dispositif assurant le secret des communications téléphoniques

Info

Publication number
FR370455A
FR370455A FR370455DA FR370455A FR 370455 A FR370455 A FR 370455A FR 370455D A FR370455D A FR 370455DA FR 370455 A FR370455 A FR 370455A
Authority
FR
France
Prior art keywords
secrecy
telephone communications
device ensuring
ensuring
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
English (en)
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.)
SELECT TELEPHONE Manufacturing Co
Original Assignee
SELECT TELEPHONE Manufacturing Co
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 SELECT TELEPHONE Manufacturing Co filed Critical SELECT TELEPHONE Manufacturing Co
Application granted granted Critical
Publication of FR370455A publication Critical patent/FR370455A/fr
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)
FR370455D 1906-10-13 1906-10-13 Dispositif assurant le secret des communications téléphoniques Expired FR370455A (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR370455T 1906-10-13

Publications (1)

Publication Number Publication Date
FR370455A true FR370455A (fr) 1907-02-07

Family

ID=1417378

Family Applications (1)

Application Number Title Priority Date Filing Date
FR370455D Expired FR370455A (fr) 1906-10-13 1906-10-13 Dispositif assurant le secret des communications téléphoniques

Country Status (1)

Country Link
FR (1) FR370455A (fr)

Similar Documents

Publication Publication Date Title
FR370455A (fr) Dispositif assurant le secret des communications téléphoniques
FR400082A (fr) Transmetteur téléphonique secret
FR377785A (fr) Dispositif de transmission téléphonique
FR427576A (fr) Dispositif pour assurer le secret des communications téléphoniques
FR367955A (fr) Appareil téléphonique et télégraphique
GB190509702A (en) Improved Field Telephone and Telegraph Apparatus
DK11508C (da) Desinfektionsanordning til Telefonapparater.
FR1319E (fr) Compteur enregistreur des communications téléphoniques
AU585506B (en) An improved combined portable telephone and telegraph instrument
FR371940A (fr) Dispositif de transmission télégraphique
FR364901A (fr) Transmetteur téléphonique
ES41403A1 (es) Mejoras introducidas en los aparatos o máquinas dictadoras por medio del teléfono.
FR363114A (fr) Appareil téléphonique
FR364900A (fr) Appareil téléphonique
ES43466A1 (es) Perfeccionamientos introducidos en los aparatos telegráficos.
FR377966A (fr) Transmetteur téléphonique
DK14824C (da) Tilbagemeldingsanordning til Telefoner og Telegrafer.
CH40703A (de) Schutzvorrichtung für Telephone zur Verhinderung der Übertragung von Krankheitskeimen
FR380921A (fr) Tableau de communications téléphoniques
FR369106A (fr) Appareil téléphonique avec appel accordé
DK7399C (da) Luftisoleret Telefon- og Telegrafkabel.
DK10739C (da) Apparat til Markering af Telefonopringning.
FR5890E (fr) Microphone et récepteur téléphoniques
DK7171C (da) Telefonforbindelsesanordning.
FR393541A (fr) Récepteur téléphonique