AT88431B
(en )
1922-05-10
Receiving device for underwater sound signals.
AT70633B
(en )
1915-12-10
Receiver for underwater sound signals.
AT71524B
(en )
1916-06-10
Receiver for underwater sound signals.
DK29827C
(en )
1922-06-26
Receiving device for underwater sound signals.
FR18527E
(en )
1914-05-13
Receiver for underwater acoustic signals
DK29642C
(en )
1922-05-22
Microphone Signal Device.
DK29579C
(en )
1922-05-15
Closed Underwater audio signal transmitter.
DK15903C
(en )
1912-04-29
Submarine Sound Signal Transmitter.
AT71320B
(en )
1919-02-25
Retractable receiver for underwater sound signals.
FR546506A
(en )
1922-11-15
Underwater acoustic receiver device
DK29920C
(en )
1922-07-10
Underwater sound system.
DK28212C
(en )
1921-08-22
Device for underwater sound devices.
ES58114A1
(en )
1914-06-16
Improvements in submarine acoustic signal receiving devices.
DK15209C
(en )
1911-10-23
Submarine Sound Signal Apparatus.
FR512131A
(en )
1921-01-15
transmitter for underwater acoustic signals
DK31175C
(en )
1923-01-22
Device for Direction Determination of Sound Waves.
AT78915B
(en )
1919-10-25
Signal apparatus for the transmission of several independent signals.
DK14892C
(en )
1911-07-31
Receiver for submarine audio signals.
ES55356A1
(en )
1913-06-16
Improvements in apparatus for underwater signals.
DK31635C
(en )
1923-04-30
Underwater sound receiver.
FR471873A
(en )
1914-11-13
Receiver for underwater acoustic signals
DK22042C
(en )
1917-04-02
Submarine.
DK29960C
(en )
1922-07-24
Device for Determining the Direction of Sound Waves.
DK33195C
(en )
1924-05-12
Sound device.
FR471562A
(en )
1914-11-03
Microphone transmitter