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IE830738L
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High-speed dial up telephone circuit full duplex¹transmission technique
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Acoustic coupler for telephone handsets - has moulded plastics cups with adjustment facility and lip bearing against microphone or speaker casing
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Tape drive apparatus for cassettes
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Telephone handset coupler
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Digital frequency discriminator
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Waveform generator
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Acoustic coupler
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Digital frequency discriminator
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Digital frequency discriminator
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