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US3480742A
(en)
|
|
Hybrid circuit
|
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FI57503C
(fi)
|
|
Talstyrd kopplingsanordning
|
|
SU410575A1
(sv)
|
|
|
|
US2481644A
(en)
|
|
Transformer responding to variations in amplitude of input waves
|
|
FI800918A
(fi)
|
|
Anordning med en gaffelkoppling foer tvaoledar-fyrledar-oevergaong i pcm-tidsmultiplexsystem
|
|
US3749857A
(en)
|
|
Cable testing device for long-distance cables, particularly for occupied cables
|
|
US4082924A
(en)
|
|
Reference signal circuit in a receiver for detecting two frequencies in a multifrequency tone signal
|
|
ES456619A1
(es)
|
|
Un aparato receptor perfeccionado para la detencion de al menos dos frecuencias vocales de una senal de tono.
|
|
US2332643A
(en)
|
|
Telephone set circuit
|
|
US3300589A
(en)
|
|
Telephone ringing circuits
|
|
US1755243A
(en)
|
|
Signaling means for telephone systems
|
|
SU374759A1
(ru)
|
|
Устройство индикации занятости абонентской телефонной линии
|
|
US2117843A
(en)
|
|
Frequency selective circuits
|
|
US1554007A
(en)
|
|
Antiside tone circuits
|
|
US1983477A
(en)
|
|
Telephone system
|
|
US1573337A
(en)
|
|
Electrical bridge
|
|
US2923778A
(en)
|
|
Signalling device for double sideband carrier current telephone systems
|
|
SU482911A1
(ru)
|
|
Разделительное устройство
|
|
US1474408A
(en)
|
|
Detecting circuit
|
|
US4412353A
(en)
|
|
Mixing circuit
|
|
US1800962A
(en)
|
|
Electric circuit
|
|
US1753325A
(en)
|
|
Retardation-coil system
|
|
US1353637A
(en)
|
|
Repeater-circuit
|
|
US1511756A
(en)
|
|
Electrical testing system
|
|
US1315584A
(en)
|
|
Selective receiving system for radiant energy |