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Radio Engineers, Proceedings of the Institute of

Issue 10 • Date Oct. 1932

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Displaying Results 1 - 13 of 13
  • Reginald A. Fessenden

    Page(s): 1548
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  • Institute notes

    Page(s): 1549 - 1553
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  • Errata

    Page(s): 1553 - 1554
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  • Direct-Ray Broadcast Transmission

    Page(s): 1555 - 1579
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    The propagation of long and short waves over long distances has been extensively studied, and the underlying principles are, to a large extent, understood. The question of the propagation of medium waves by direct ray, which forms the subject of the following paper, has not previously received so much attention. The paper is written with a view of enabling predictions to be made as to the field strength of direct-ray transmission on wavelengths between 60 meters and 2000 meters. The main part of the paper is concerned with daylight transmission. The question of night transmission and the influence of the Heaviside layer is considered briefly at the end. View full abstract»

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  • Visual Test Devices

    Page(s): 1580 - 1598
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    A device for showing on a screen the frequency-response curve of a tuned circuit, tuned transformer, amplifier or complete radio set is described in this paper. The action of the device is practically instantaneous, and the effect of circuit adjustments may be seen immediately. The principles and operation of the device are explained, and it is shown how the derivative of the response curve may be obtained electrically and shown on the screen, to allow more accurate location of the resonant frequency, by giving a sharp crossing of the axis at that frequency. Operating characteristics and fidelity curves for the latest development of this device are given. View full abstract»

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  • Copper-Oxide Rectifier Used for Radio Detection and Automatic Volume Control

    Page(s): 1599 - 1614
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    A new type of radio detector has been developed which depends for its action on the rectifying properties of the boundary between copper and cuprous oxide formed on the copper at a high temperature. In order to make the copper-oxide rectifier useful up to broadcast frequencies, it was necessary to use small disks and a high current density. The high current density was obtained in part by connecting an inductance in parallel with the rectifier and tuning it with the rectifier capacity. The circuits developed possess unique advantages in that harmonic distortion is practically eliminated, a stage of audio-frequency amplification is eliminated, and automatic volume control of variable , μ tubes as well as other tubes is achieved without the necessity of using an auxiliary tube for volume control. A newform of automatic volume control made possible by the use of a single rectifier element as an asymmetrical resistance is described and discussed. View full abstract»

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  • The Detection of Microwaves

    Page(s): 1615 - 1625
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    The results of researches made to recognize the best conditions in which triodes can be used for the detection of microwaves (frequencies of about 109per sec) are reported here. It seems that the detecting triodes, which must have their grids at a very high positive potential and the anode at a potential just lower than that of the positive end of the wire, act simply like rectifying diodes with electrodes very near to one another. View full abstract»

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  • A New Electrical Method of Frequency Analysis and Its Application to Frequency Modulation

    Page(s): 1626 - 1639
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    A method of analyzing an arbitrary combination of sine wave voltages is described and the analysis of several examples carried out. The method is based on the appearance of certain figures, typical of definite frequency ratios, appearing in an oscillogram of the superposition of a constant frequency and a "search" voltage. The resolving power of the method is very high, allowing component voltages of only two cycles per second frequency difference to be clearly resolved. A frequency modulated wave is then analyzed and the spectrum representation f(t)=n-0 Jn(Δf/α) sin 2π(f+nα)t found to hold under the approximate conditions Δf<f0/10, α<f0/10. The consequences of the periodicity or nonperiodicity which can occur with relatively large Δf and α is discussed. A simple expression for the spectrum of a wave with both amplitude and frequency modulation is derived, which allows an immediate oversight of the changes in side band magnitude occurring when one type of undesired modulation accompanies the other. Finally, the relation of the oscillogram of superposed constant frequency and search voltages to Lissajous figures is pointed out, and a comparison with diatonic harmony made. View full abstract»

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  • A Fourier Analysis of Radio-Frequency Power Amplifier Wave Forms

    Page(s): 1640 - 1659
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    A theoretical treatment of class B and C radio-frequency amplifier wave forms by means of the Fourier series is presented. Assuming constant plate tuned circuit impedance, general expressions for the Fourier coefficients for any value of grid bias from cut-off to the position for class A operation are derived. The variation in plate circuit efficiency as the bias is moved from the position for class A operation to cut-off is considered. Ideal wave forms with which class C operation would be obtained are analyzed. The extent to which the ideal forms may be approached in actual operation is considered and a wave form which may be approximated in practice is analyzed. The efficiency of the several wave forms is discussed. View full abstract»

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  • Note on Network Theory

    Page(s): 1660 - 1664
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    Passive transducers may be connected in any manner between two pairs of terminals to form a resultant passive transducer between those terminals. In this note are given or indicated general expressions for the important properties of such a resultant transducer in terms of those of the transducers forming it for the case in which the arrangement of the subsidiary transducers can be achieved by some combination of series and parallel connections. Section (a) treats of transducers in parallel; (b), in series; (c), in series-parallel. View full abstract»

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  • Book reviews

    Page(s): 1665
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  • Radio abstracts and references

    Page(s): 1666 - 1673
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  • Contributors to this issue

    Page(s): 1674 - 1675
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Aims & Scope

This Periodical ceased production in 1938. The current retitled publication is Proceedings of the IEEE.

Full Aims & Scope