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SE179533C1
(OSRAM)
|
|
|
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GB1351408A
(en)
|
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Pcm t d m telecommunications exchange systems
|
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US2416109A
(en)
|
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Rotary type selector switch for automatic telephone systems
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US2744245A
(en)
|
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Rectangular coordinate registering circuit
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GB355924A
(en)
|
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Improvements relating to automatic telephone systems
|
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US2490054A
(en)
|
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Party line telephone system
|
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US1545025A
(en)
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Automatic telephony
|
|
US1854106A
(en)
|
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Automatic telephone system
|
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GB804691A
(en)
|
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Improvements in or relating to control units for switching systems
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US2377544A
(en)
|
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Electric signaling system |
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SE178037C1
(OSRAM)
|
|
|
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US2431692A
(en)
|
|
Alternate route telephone switching mechanism
|
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US2364796A
(en)
|
|
Trouble indicating system
|
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US2887538A
(en)
|
|
Telephone or like systems
|
|
US2101254A
(en)
|
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Testing circuit
|
|
US1810004A
(en)
|
|
Voice operated relay circuits
|
|
US1601702A
(en)
|
|
Measured-service telephone system
|
|
US1470664A
(en)
|
|
mcberty |
|
US1434283A
(en)
|
|
Telegraph
|
|
US1867791A
(en)
|
|
Automatic telephone system
|
|
US1603267A
(en)
|
|
Telephone system
|
|
US1816570A
(en)
|
|
Testing system
|
|
US1848399A
(en)
|
|
Telephone system
|
|
US1862532A
(en)
|
|
Telephone system
|
|
US1526402A
(en)
|
|
Loop circuits for telegraph repeaters
|