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US3991288A
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Repeater housing assembly
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US3886317A
|
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Synchronous data channel for pulse code modulation communications system
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US3879724A
|
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Integrating analog to digital converter
|
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US3876838A
|
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Carrier concentrator system and method
|
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US3870823A
|
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Telephone exchange metering system
|
|
US3885102A
|
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Message metering system having multi-level signals and party discrimination
|
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US3864533A
|
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Automatic line transfer system and method for a communications system
|
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US3829893A
|
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Tape speed monitor
|
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US3870824A
|
|
Redundant data transmission system
|
|
US3852533A
|
|
Sampling and analog-to-digital converter apparatus for use in a telephone message metering system
|
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US3818456A
|
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Message metering system
|
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US3742389A
|
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Voltage to frequency converter having dual standard charge dispensers
|
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US3631342A
|
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Digital voltmeter apparatus employing a bipolar amplifier having a unidirectional output and a voltage controlled oscillator
|
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US3566312A
|
|
Switchable filter network
|
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US3408602A
|
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Shielded switching device
|
|
US3517339A
|
|
Voltage to frequency converter having symmetrical waveshape output with fundamental frequency proportional to input signal
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US3204201A
|
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Shielded circuit
|
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US3205448A
|
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Frequency to voltage converter
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