GB1444810A - Method for varying the frequencies of a communication signal - Google Patents

Method for varying the frequencies of a communication signal

Info

Publication number
GB1444810A
GB1444810A GB4552573A GB4552573A GB1444810A GB 1444810 A GB1444810 A GB 1444810A GB 4552573 A GB4552573 A GB 4552573A GB 4552573 A GB4552573 A GB 4552573A GB 1444810 A GB1444810 A GB 1444810A
Authority
GB
United Kingdom
Prior art keywords
frequency
signal
control signal
frequencies
input
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB4552573A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TDK Micronas GmbH
ITT Inc
Original Assignee
Deutsche ITT Industries GmbH
ITT Industries Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Deutsche ITT Industries GmbH, ITT Industries Inc filed Critical Deutsche ITT Industries GmbH
Publication of GB1444810A publication Critical patent/GB1444810A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
    • H04M9/087—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic using different frequency bands for transmitting and receiving paths ; using phase shifting arrangements
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Transceivers (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)
  • Electromechanical Clocks (AREA)

Abstract

1444810 Frequency modulation; preventing acoustic reaction; signal compression ITT INDUSTRIES Inc 28 Sept 1973 [7 Oct 1972] 45525/73 Headings H3R H3J and H4R In a method of varying the frequency of an input signal in dependence on a control signal, the signal to be varied is delayed by an electronic analogue delay line having a delay determined by the frequency of a clock signal, the clock signal being frequency modulated by the control signal. If the control signal is of triangular waveform, frequency-shift keying of the input signal is acheived because during the leading edge of the triangular wave, the frequencies of the input signal are shifted up in frequency, and during the trailing edge they are shifted down in frequency. If a sawtooth control signal is used, a frequency shift in one direction is achieved. Such an arrangement may be utilized to illuminate acoustic feedback when a microphone and loud-speaker are used in close proximity. Alternatively, the control signal may consist of a band of frequencies having an arbitarily chosen frequency distribution. If the frequency variation is made sufficiently large, a speech signal input may be rendered unintelligible, or encoded.
GB4552573A 1972-10-07 1973-09-28 Method for varying the frequencies of a communication signal Expired GB1444810A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2249257A DE2249257A1 (en) 1972-10-07 1972-10-07 PROCEDURE FOR CHANGING THE FREQUENCIES OF A MESSAGE SIGNAL

Publications (1)

Publication Number Publication Date
GB1444810A true GB1444810A (en) 1976-08-04

Family

ID=5858443

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4552573A Expired GB1444810A (en) 1972-10-07 1973-09-28 Method for varying the frequencies of a communication signal

Country Status (6)

Country Link
JP (1) JPS4974407A (en)
DE (1) DE2249257A1 (en)
FR (1) FR2202401B1 (en)
GB (1) GB1444810A (en)
IT (1) IT1003145B (en)
ZA (1) ZA737683B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2151886A (en) * 1983-12-21 1985-07-24 British Broadcasting Corp Conditional-access broadcast transmission
WO2007049200A1 (en) 2005-10-24 2007-05-03 Koninklijke Philips Electronics N.V. A device for and a method of audio data processing

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
HU169185B (en) * 1974-06-05 1976-10-28

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3444396A (en) * 1965-03-24 1969-05-13 Rca Corp Signal translating circuit providing signal-controlled time delay
US3559103A (en) * 1965-10-05 1971-01-26 Duane H Cooper Method of delay modulation
AU459101B2 (en) * 1972-02-10 1975-03-20 Matsushita Electric Industrial Co., Ltd. Samplling modulation system for an electronic misical instrument
US3749837A (en) * 1972-05-02 1973-07-31 J Doughty Electronic musical tone modifier for musical instruments

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2151886A (en) * 1983-12-21 1985-07-24 British Broadcasting Corp Conditional-access broadcast transmission
WO2007049200A1 (en) 2005-10-24 2007-05-03 Koninklijke Philips Electronics N.V. A device for and a method of audio data processing

Also Published As

Publication number Publication date
DE2249257A1 (en) 1974-04-11
FR2202401A1 (en) 1974-05-03
ZA737683B (en) 1974-08-28
IT1003145B (en) 1976-06-10
FR2202401B1 (en) 1977-03-11
JPS4974407A (en) 1974-07-18

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Legal Events

Date Code Title Description
PS Patent sealed
746 Register noted 'licences of right' (sect. 46/1977)
PCNP Patent ceased through non-payment of renewal fee