Your browser does not support JavaScript!
http://iet.metastore.ingenta.com
1887

Proceedings of the IEE - Part III: Radio and Communication Engineering

Volume 98, Issue 53, May 1951

Volumes & issues:

Volume 98, Issue 53

May 1951

Crystal diodes
  • Author(s): R.W. Douglas  and  E.G. James
  • Source: Proceedings of the IEE - Part III: Radio and Communication Engineering, Volume 98, Issue 53, p. 157 –168
  • DOI:  10.1049/pi-3.1951.0033
  • Type: Article
  • + Show details - Hide details
  • p. 157 –168 (12)
    The first part of the paper gives the current views of the manner in which very small amounts of impurities give rise to the special electrical properties of semi-conductors, and of the mechanism of contact rectification. The preparation of germanium and silicon for use in crystal diodes is considered and the steps found necessary in the processing are discussed in terms of the theoretical ideas.In the second part of the paper, the design and performance of (a) a new coaxial-type silicon-crystal diode intended for use as a mixer at frequencies up to about 10 000 Mc/s, (b) a wire-ended germanium-crystal diode, are described and discussed. Particular attention is given to the frequency dependence of the rectification efficiency of the germanium diode, and its application as a replacement for the thermionic diode.
    Add to favourites
    Export citations
Crystal triodes
Discussion on “Crystal diodes” and “Crystal triodes”
The authors' replies to the discussions on “Crystal diodes” and “Crystal triodes”
Have post-war broadcast receivers taken full advantage of war-time development? Radio Section discussion meeting, 18th December, 1950
The use of saturable reactors as discharge devices for pulse generators
  • Author(s): W.S. Melville
  • Source: Proceedings of the IEE - Part III: Radio and Communication Engineering, Volume 98, Issue 53, p. 185 –206
  • DOI:  10.1049/pi-3.1951.0038
  • Type: Article
  • + Show details - Hide details
  • p. 185 –206 (22)
    The subject of recurrent high-power pulse generation may be considered as including pulse generators for radar modulation, nuclear-particle acceleration, impulse testing, and auxiliary and ancillary circuits such as initiators and sub-modulators for more powerful discharge devices, e.g. initiators igniter firing-circuits. In generators of these types it has been customary to use electronic discharge devices which depend for their operation on the conducting properties of electric arcs as the means of rapidly discharging capacitive pulse-forming networks into appropriate utilization circuits. While these devices are, in general, satisfactory for many applications, it is well known that they have inherent disadvantages.Comparatively recent developments in the field of high-permeability high-saturation-flux-density magnetic materials having characteristically rectangular hysteresis loops, together with new circuits designed to take advantage of their special properties, have made it possible to overcome many of the disadvantages of electronic discharge devices by replacing them with static components having indefinitely long lives.The paper outlines the historical background to the development of some of the circuits and materials and describes the operation of circuits designed to fulfil the duties of radar pulse-modulators and ignitron firing circuits. Some practical and theoretical considerations affecting the design of the special components peculiar to the work are also described.
    Add to favourites
    Export citations
Discussion on “The use of saturable reactors as discharge devices for pulse generators” before the Radio Section, 10th January, 1951
The author's reply to the discussion on “The use of saturable reactors as discharge devices for pulse generators”
How reliable is a radio valve? Radio Section discussion meeting, 26th January, 1951
Comparison of ionospheric radio transmission forecasts with practical results
  • Author(s): A.F. Wilkins  and  C.M. Minnis
  • Source: Proceedings of the IEE - Part III: Radio and Communication Engineering, Volume 98, Issue 53, p. 209 –220
  • DOI:  10.1049/pi-3.1951.0042
  • Type: Article
  • + Show details - Hide details
  • p. 209 –220 (12)
    The production of m.u.f. forecasts for oblique transmission involves numerous operations on basic information obtained at vertical incidence. At each stage, errors are introduced whose cumulative effect determines the difference between predicted and observed circuit performance. The sources of the errors are examined and tentative values assigned to them with special reference to F2-region.The computed value of the total error is compared with results obtained on commercial and Service circuits, and with observations made by other means. It is concluded that although, on the average, agreement is good, discrepancies remain which need further examination after the elimination of known sources of error.In a few cases, comparisons of predicted and actual times of fades due to ionospheric absorption have been made. Although the agreement between these times is reasonably good, it is believed that predictions of the actual field strength may be in error by large amounts.
    Add to favourites
    Export citations
The ionospheric propagation of low- and very-low-frequency radio waves over distances less than 1000 km
  • Author(s): R.N. Bracewell ; K.G. Budden ; J.A. Ratcliffe ; T.W. Straker ; K. Weekes
  • Source: Proceedings of the IEE - Part III: Radio and Communication Engineering, Volume 98, Issue 53, p. 221 –236
  • DOI:  10.1049/pi-3.1951.0043
  • Type: Article
  • + Show details - Hide details
  • p. 221 –236 (16)
    In the last few years a large part of the radio research at the Cavendish Laboratory has been concerned with the propagation of waves of low and very low frequency. The paper constitutes a summary of the results of the various experiments, which are described in detail in separate papers, some of which are as yet unpublished.3–10The results of various independent methods of measuring the apparent height of reflection of the waves show that waves of 16–30 kc/s are reflected as if from a sharply bounded horizontal surface situated at a height of (72 ± 3) km when the sun is overhead. The apparent height of reflection varies regularly with the angle of the sun and its variation may be summarized by an equation. The waves of frequency 30–150 kc/s appear to be reflected from a height of about 75 km at oblique incidence, but there is some evidence that they may be reflected from as much as 10 km higher at vertical incidence.The polarization of the waves at all frequencies is found to be approximately circular at steep incidence, but at oblique incidence (65 ) waves of a frequency of 16 kc/s are linearly polarized. No measurements of polarization at oblique incidence have been made on the higher frequencies.The absorption of the waves changes very rapidly with frequency—on a summer day the conversion coefficient varies from about 0.15 at 16 kc/s to 0.002 at 70 kc/s. Important differences in behaviour near sunrise are observed on all frequencies at steep incidence and oblique incidence. The effects of a sudden ionospheric disturbance on the reflected waves are discussed and interpreted as implying a decrease in the apparent height of reflection; the amplitude of the reflected wave is scarcely altered on 16 kc/s, but is much decreased on higher frequencies.Finally, the present state of the theory of reflection of very long radio waves is discussed very briefly.
    Add to favourites
    Export citations
A wide-band aerial system for circularly polarized waves, suitable for ionospheric research
Some notes on overtone crystals and maintaining oscillators operating in the frequency range of 33–55 Mc/s
  • Author(s): J.B. Supper
  • Source: Proceedings of the IEE - Part III: Radio and Communication Engineering, Volume 98, Issue 53, p. 240 –247
  • DOI:  10.1049/pi-3.1951.0045
  • Type: Article
  • + Show details - Hide details
  • p. 240 –247 (8)
    The paper investigates the behaviour of overtone crystals in two general forms of maintaining circuit. The terms “minimum impedance” and “inductive impedance” are suggested as descriptive of these two general forms, and the concept of “impedance diameter” as a measure of crystal goodness is introduced.Records are made of measurements on different types of crystals and of their behaviour in the inductive impedance oscillator; the results demonstrate the superiority of some types over others. The effect of plating area on crystals is discussed, and attention is drawn to the improvement obtained by reducing the standard value used.
    Add to favourites
    Export citations
Discussion on “A Royal Air Force Calibration Centre” before the Southern Centre, at Farnborough, 22nd February, 1950
Discussion on “Eddy-current and screen losses of a screened single-layer solenoid”
Electrostatic induction by power lines in parallel telephone lines and at crossings
The determination of time and frequency
Frequency standardization
Meetings of the Radio Section: abridged minutes

Most viewed content for this Journal

Article
content/journals/pi-3
Journal
5
Loading

Most cited content for this Journal

We currently have no most cited data available for this content.

Print this page
This is a required field
Please enter a valid email address