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| 1. |
Proceedings of the Wireless Section |
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Journal of the Institution of Electrical Engineers - Part III: Communication Engineering, including the Proceedings of the Wireless Section of the Institution,
Volume 89,
Issue 5,
1942,
Page 1-1
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PDF (100KB)
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DOI:10.1049/ji-3-1.1942.0001
出版商:IEE
年代:1942
数据来源: IET
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| 2. |
Wireless Section: Chairman's address. “A review of technical developments in broadcasting” |
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Journal of the Institution of Electrical Engineers - Part III: Communication Engineering, including the Proceedings of the Wireless Section of the Institution,
Volume 89,
Issue 5,
1942,
Page 2-18
H.Bishop,
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PDF (2892KB)
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DOI:10.1049/ji-3-1.1942.0002
出版商:IEE
年代:1942
数据来源: IET
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| 3. |
The transmission characteristics of asymmetric-sideband communication networks |
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Journal of the Institution of Electrical Engineers - Part III: Communication Engineering, including the Proceedings of the Wireless Section of the Institution,
Volume 89,
Issue 5,
1942,
Page 19-39
E. ColinCherry,
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PDF (2174KB)
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摘要:
This paper deals with an investigation into some theoretical and practical aspects of the partial suppression of one or both sidebands of a modulated carrier wave. The work is primarily of interest in connection with asymmetric-sideband television broadcasting channels.The envelope distortion and carrier phase modulation produced by a channel of asymmetric characteristics are derived, and experiments are described which demonstrate some of the effects in such channels. A method is described of obtaining the “equivalent modulation characteristics” of an asymmetric-sideband channel, which is exact for all types of modulation envelope at any modulation depths. In the analysis quite general channel characteristics are assumed, and not “idealized” forms.
DOI:10.1049/ji-3-1.1942.0003
出版商:IEE
年代:1942
数据来源: IET
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| 4. |
Voice-frequency signalling and dialling in long-distance telephony |
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Journal of the Institution of Electrical Engineers - Part III: Communication Engineering, including the Proceedings of the Wireless Section of the Institution,
Volume 89,
Issue 5,
1942,
Page 43-64
W.G.Radley,
E.P.G.Wright,
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摘要:
During the 21 years between the two great European wars telephone systems of the majority of the cities and large towns of the world have been converted from manual to automatic operation. During the same period notable improvements have also been made to the long-distance telephone service.The introduction of the use of voice-frequency currents for signalling and dialling represents a stage in a long process of development, and the main portion of this paper describes the problems encountered in the design of a system and the various methods which may be employed for avoiding interference between signals and other currents in the voice-frequency range. Reference is also made to the recommendations of the C.C.I.F. regarding the means of avoiding interference between different signalling systems on international connections.The interruption in development caused by the present war provides an opportunity for a review of the progress made and for a consideration of future lines of development necessary to keep pace with changes in automatic switching and speech transmission. Therefore, while the paper starts by setting forth the reasons for modern methods of signalling and dialling over long-distance circuits and for preferring the use of voice-frequency currents for these purposes, it concludes by considering the possible trend of future development.
DOI:10.1049/ji-3-1.1942.0005
出版商:IEE
年代:1942
数据来源: IET
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Volume 89 issue 5