FR677475A - Improvements to microphones and similar devices - Google Patents

Improvements to microphones and similar devices

Info

Publication number
FR677475A
FR677475A FR677475DA FR677475A FR 677475 A FR677475 A FR 677475A FR 677475D A FR677475D A FR 677475DA FR 677475 A FR677475 A FR 677475A
Authority
FR
France
Prior art keywords
microphones
similar devices
similar
devices
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)
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.)
Submarine Signal Co
Original Assignee
Submarine Signal 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 Submarine Signal Co filed Critical Submarine Signal Co
Application granted granted Critical
Publication of FR677475A publication Critical patent/FR677475A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
    • G01S1/72—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using ultrasonic, sonic or infrasonic waves

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
FR677475D 1929-06-26 1929-06-26 Improvements to microphones and similar devices Expired FR677475A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR677475T 1929-06-26

Publications (1)

Publication Number Publication Date
FR677475A true FR677475A (en) 1930-03-11

Family

ID=9020492

Family Applications (1)

Application Number Title Priority Date Filing Date
FR677475D Expired FR677475A (en) 1929-06-26 1929-06-26 Improvements to microphones and similar devices

Country Status (1)

Country Link
FR (1) FR677475A (en)

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