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Voice Elimination for Parallel Tone Receiver

IP.com Disclosure Number: IPCOM000090071D
Original Publication Date: 1969-Jan-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Abramson, P: AUTHOR

Abstract

One form of parallel tone transmission consists of the simultaneous transmission of an A tone and a B tone. In this type of receiver, there appears a corresponding 2-out-of-5 code output for each A and B tone. A basic requirement of the system is that the human voice should not produce an output which could be mistaken for a legitimate parallel tone transmission.

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Voice Elimination for Parallel Tone Receiver

One form of parallel tone transmission consists of the simultaneous transmission of an A tone and a B tone. In this type of receiver, there appears a corresponding 2-out-of-5 code output for each A and B tone. A basic requirement of the system is that the human voice should not produce an output which could be mistaken for a legitimate parallel tone transmission.

An A tone A-I of 697, A-II of 770, A-III of 852, or A-IV of 941cps and a B tone B-I of 1209, B-II of 1336, B-III of 1477, or B-IV of 1633 cps are simultaneously sent from a parallel A and B tone transmitter to a parallel tone receiver. Tone A-I yields A0 and A1 receiver unit outputs, A-II yields A1 and A2 outputs, A-III yields A2 and A3 outputs, A-IV yields A3 and A4 outputs. Tone B-I yields B0 and B1 outputs, B-II yields B1 and B2 outputs, B-III yields B2 and B3 outputs, and B-IV yields B3 and B4 outputs.

In audio parallel tone transmission, protection against response to voice is provided by logic, responsive to the above two-out-of-five code in combination with a time delay of forty milliseconds which exceeds the normal duration of voice tones. Tones A1 and A3 go to one-out-two tones logic unit 3. Tones A0, A2, and A3 go to one-out-of-three tones logic unit 4. Tones B1 and B3 go to one-out-of- two tones unit 5, and tones B0, B2 and B4 go to one-out-of-three tones unit 6. If and only if each one of the units 3...6 is receiving a single tone, And 7 turns on s...