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GB703801A
|
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Improvements in or relating to voice switching in telephone transmission systems
|
|
GB701607A
|
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Improvements in or relating to two-way telecommunication systems
|
|
GB614638A
|
|
Improvements in and relating to loudspeaking telephone systems
|
|
GB525470A
|
|
Improvements in and relating to thermionic valve circuits
|
|
GB522758A
|
|
Improvements in or relating to telephone systems
|
|
GB509693A
|
|
Improvements in electric signal amplifiers incorporating voice-operated devices
|
|
GB491126A
|
|
Improvements in electric signal amplifiers
|
|
GB474428A
|
|
Improvements in or relating to alternating current signalling systems
|
|
IE13883L
|
|
Telephony
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|
IE13573L
|
|
Telephony
|
|
GB444598A
|
|
Improvements in or relating to electrical signalling systems employing speech or voice current signals
|
|
GB430567A
|
|
Improvements in or relating to telephone systems
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|
GB425308A
|
|
Improvements in alternating current oscillatory circuits
|
|
GB426396A
|
|
Means for controlling the voltage generated by an alternating current oscillator
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|
GB420387A
|
|
Improvements in alternating current signal receivers
|
|
GB418442A
|
|
Improvements in or relating to electric signalling systems
|
|
GB415767A
|
|
Improvements in alternating current transmission systems such as telephone systems incorporating echo suppressors
|
|
GB413383A
|
|
Variable attenuation networks capable of providing automatic volume control of alternating signal currents
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GB408391A
|
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Improvements in heterodyne alternating current generators
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GB409360A
|
|
Improvements in alternating current signal generators and amplifiers
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