CH277495A
(en )
1951-08-31
Messaging system.
CH294912A
(en )
1953-11-30
Automatic telephony installation.
CH282556A
(en )
1952-04-30
Radio receiver.
CH265981A
(en )
1949-12-31
Receiving circuitry for low frequency or carrier power telephone systems.
CH266246A
(en )
1950-01-15
Transmitter for a carrier wave telephony system.
CH280689A
(en )
1952-01-31
Directed radio transmitter.
DK71003C
(en )
1950-05-15
Transmitter connection for carrier telephone systems.
CH289544A
(en )
1953-03-15
Powerline communication installation.
CH284629A
(en )
1952-07-31
Communication facility.
CH279482A
(en )
1951-11-30
Shared line telephone system.
CH275982A
(en )
1951-06-15
Equalizing transmitter for telegraph signals.
CH301274A
(en )
1954-08-31
Single sideband carrier frequency telephone system.
DK77958C
(en )
1954-08-16
Receiver connection for low frequency or carrier telephony systems.
CH262449A
(en )
1949-06-30
Automatic telephone system.
CH273328A
(en )
1951-02-15
Pumping system.
CH271268A
(en )
1950-10-15
Television system.
DK80669C
(en )
1956-03-12
Signaling systems, in particular for automatic telephone systems.
CH281906A
(en )
1952-03-31
Telegraph installation.
DK79135C
(en )
1955-04-18
Multiplex transmission system.
CH263435A
(en )
1949-08-31
Telephone system.
IE19114L
(en )
1948-03-04
Carrier telephony.
AU139746B2
(en )
1947-05-08
Communication systems
CA443406A
(en )
1947-08-05
Telephone signalling system
IE18227L
(en )
1947-11-28
Two-way communication systems.
IE17791L
(en )
1947-04-05
Telephone systems.