GB1444810A - Method for varying the frequencies of a communication signal - Google Patents
Method for varying the frequencies of a communication signalInfo
- 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
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)
- Electromechanical Clocks (AREA)
- Interconnected Communication Systems, Intercoms, And Interphones (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.
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)
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)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
HU169185B (en) * | 1974-06-05 | 1976-10-28 |
Family Cites Families (4)
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 |
-
1972
- 1972-10-07 DE DE2249257A patent/DE2249257A1/en active Pending
-
1973
- 1973-09-28 GB GB4552573A patent/GB1444810A/en not_active Expired
- 1973-10-01 ZA ZA737683A patent/ZA737683B/en unknown
- 1973-10-02 FR FR7335126A patent/FR2202401B1/fr not_active Expired
- 1973-10-04 IT IT29726/73A patent/IT1003145B/en active
- 1973-10-08 JP JP48112421A patent/JPS4974407A/ja active Pending
Cited By (2)
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 |
JPS4974407A (en) | 1974-07-18 |
ZA737683B (en) | 1974-08-28 |
FR2202401A1 (en) | 1974-05-03 |
FR2202401B1 (en) | 1977-03-11 |
IT1003145B (en) | 1976-06-10 |
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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 |