FR502421A
(en )
1920-05-14
Telephone transmitter
AT96060B
(en )
1924-02-25
Device for wireless transmission of telephone and telegraph signals.
AT91059B
(en )
1923-01-25
Telegraph with secret transmission.
AT96062B
(en )
1924-02-25
Device for the transmission of telephone and telegraphic signals by means of high frequency waves.
ES72354A1
(en )
1920-04-09
Signals on radio telegraph devices.
DK32296C
(en )
1923-09-24
Audio receiver for wireless Telegraphy and Telephony.
FR517422A
(en )
1921-05-06
Advanced telephone transmitter
CA195097A
(en )
1919-12-23
Telephone and telegraph device
DK32568C
(en )
1923-12-03
Procedure and Device for Affecting Incoming Wireless Signals.
DK33290C
(en )
1924-05-26
Telegraph receiver.
AT96063B
(en )
1924-02-25
Telephone transmitter arrangement.
DK30997C
(en )
1922-12-27
Telegraphic Receiver.
FR490806A
(en )
1919-05-10
Receiver for telephones and microtelephones
DK21914C
(en )
1917-02-19
Transmitter device for wireless Telegraphy and Telephony.
DK33125C
(en )
1924-04-22
Transmission system for High Frequency Telegraphy and the like.
FR21805E
(en )
1921-03-30
Transmission system for combined telephone and telegraph services
ES71597A1
(en )
1920-05-10
A mechanical transmitting telegraph apparatus of the Morse alphabet.
DK25198C
(en )
1919-11-17
Procedure and Apparatus for Transmitting Signals, Speech and Other Messages.
FR532699A
(en )
1922-02-09
Duplex telephone and telegraph coupling with amplifiers
FR615741A
(en )
1927-01-14
Pavilion for acoustic headphones of phonographs, telegraphs, telephones, radio telegraphs and radio telephones, etc.
FR508847A
(en )
1920-10-25
Gray telegraph
FR509003A
(en )
1920-10-29
Telephone transmitter
DK29853C
(en )
1922-07-03
Transmitter for Wireless Telegraphy.
ES76557A1
(en )
1921-02-16
Wireless duplex telegraphy or telephony system or with them.
ES70366A1
(en )
1919-09-01
Telephone hearing.