IE32501L
(en )
1969-05-23
Data transmission system
US3824344A
(en )
1974-07-16
Conference bridge circuit
IE810195L
(en )
1981-08-11
Electronic hybrid circuit
US4301336A
(en )
1981-11-17
Hybrid circuit
US4234970A
(en )
1980-11-18
Fiber optic communication system
PL70141B2
(no )
1974-02-28
GB1351408A
(en )
1974-05-01
Pcm t d m telecommunications exchange systems
US2035536A
(en )
1936-03-31
Interconnection of transmission lines
US4326109A
(en )
1982-04-20
Apparatus for coupling a two-way transmission path to a one-way transmitting path and a one-way receiving path
US2303419A
(en )
1942-12-01
Two-way signal transmission system
GB563504A
(en )
1944-08-17
Improvements in telephone or like systems
JPS5599854A
(en )
1980-07-30
Ring shape photo communication unit
JPS56124963A
(en )
1981-09-30
Coupling system of double composite system
US1352828A
(en )
1920-09-14
Four-wire circuit
US2069224A
(en )
1937-02-02
Interconnecting telegraph repeater system
GB398812A
(en )
1933-09-19
Improvements in or relating to telephone systems or the like
JPS5597715A
(en )
1980-07-25
180-degrees phase shifter
GB794441A
(en )
1958-05-07
Improvements in or relating to duplexers
ATE4018T1
(de )
1983-07-15
Koppelfeld mit verbindungswegeumkehr, insbesondere fuer fernsprechvermittlungsanlagen.
US2259637A
(en )
1941-10-21
Telegraph repeater
JPS56132858A
(en )
1981-10-17
Subscriber's line signal system
JPS577655A
(en )
1982-01-14
General multiple address transmission system
JPS63304776A
(ja )
1988-12-13
共同受信用分岐増幅器
JPS56128039A
(en )
1981-10-07
Two-way amplifier of two-wire system
JPS55150639A
(en )
1980-11-22
Data transmission unit