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Journal of the Institution of Electrical Engineers - Part III: Radio and Communication Engineering

Volume 93, Issue 24, July 1946

Volumes & issues:

Volume 93, Issue 24

July 1946

Proceedings of The Institution
A standard of frequency and its applications
  • Author(s): C.F. Booth  and  F.J.M. Laver
  • Source: Journal of the Institution of Electrical Engineers - Part III: Radio and Communication Engineering, Volume 93, Issue 24, p. 223 –236
  • DOI:  10.1049/ji-3-2.1946.0037
  • Type: Article
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  • p. 223 –236 (14)
    The paper discusses the importance of frequency standardization to the telecommunication engineer, and outlines the work which the Post Office has carried out in this field. As published information on the subject is scanty, the historical development of frequency standards is reviewed, a bibliography is included and the factors affecting the design of a standard are briefly analysed. The design, performance and application of the Post Office standard are considered in some detail. In particular, the absolute calibration of the group of crystal-controlled oscillators comprising the standard is discussed, and details are given of equipment designed for the precise intercomparison of the frequencies of the individual oscillators. A specialized form of frequency standard, known as a “quartz clock,” which is now being used by astronomers in addition to the older type of pendulum clock, is briefly described.The methods available for the comparison, both national and international, of frequency standards are analysed, and a résumé of international comparisons reveals the advances achieved in frequency standardization during the past two decades. At present it is considered that the absolute value of the Post Office standard of frequency is known to ±1×10−8. Finally, the development work now being carried out to improve the stability and reliability of the standard is outlined.
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Discussion on “A standard of frequency and its applications” before the Radio Section, 16th January, 1946
The authors' reply to the discussion on “A standard of frequency and its applications”
Electrical contact springs. Radio Section meeting
An introduction to hyperbolic navigation, with particular reference to Loran
Discussion on “An introduction to hyperbolic navigation, with particular reference to Loran” before the Institution, 24th January, 1946
The author's reply to the discussion on “An introduction to hyperbolic navigation, with particular reference to Loran”
A method of transmitting sound on the vision carrier of a television system
  • Author(s): D.I. Lawson ; A.V. Lord ; S.R. Kharbanda
  • Source: Journal of the Institution of Electrical Engineers - Part III: Radio and Communication Engineering, Volume 93, Issue 24, p. 251 –267
  • DOI:  10.1049/ji-3-2.1946.0044
  • Type: Article
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  • p. 251 –267 (17)
    The paper describes a television system in which sound pulses having a constant height and variable width are inserted in the line synchronizing periods. It is claimed that this method of transmission leads to a simplified receiver and that the programme quality is better in the presence of severe interference. Other advantages are that the frequency band-width for transmission is reduced; the method of receiving sound ensures automatic volume control; the sound pulses provide a fixed reference level for automatic volume control on the vision channel; mutual interference between vision and sound often present on two-channel reception is avoided; reduced transmission band-width simplifies the design of the receiving antenna; mutual coupling between the vision and sound antennae at the transmitter is avoided; and the installation and maintenance costs of the sound transmitter are saved.The frequency range of the system operated in conjunction with the pre-war British transmission would be limited to 5 kc/s.
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Discussion on “A method of transmitting sound on the vision carrier of a television system” before the Radio Section, 30th January, 1946
The authors' reply to the discussion on “A method of transmitting sound on the vision carrier of a television system”
Practical aspects of telephone interference arising from power systems
Some Applications of Field Plotting
Discussion on “Studio technique in television” before the North-Western Radio Group, at Manchester, 12th October, 1945
Discussion on “Notes on the stability of LC oscillators” before the Cambridge Radio Group, 29th October, 1945
The power rating (thermal) of radio-frequency cables

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