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Radio Engineers, Proceedings of the Institute of

Issue 4 • Date Aug. 1920

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Displaying Results 1 - 13 of 13
  • [Front cover]

    Page(s): c1 - c2
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    Freely Available from IEEE
  • Contents

    Page(s): 261
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  • Correction [to Proc. IRE, April, 1920, vol 8, no 2, pg 165]

    Page(s): 261
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    A corrected formula is presented for the one that appears in The PROCEEDINGS OF THE INSTITUTE OF RADIO ENGINEERS for April, 1920, volume 8, number 2, page 165, on line 3. Also, a correction is made to the seventh column of the second portion of Table 1. View full abstract»

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  • General Information

    Page(s): 261
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  • Officers and Board of Direction, 1920

    Page(s): 262
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    Freely Available from IEEE
  • Trans-Oceanic Radio Communication

    Page(s): 263 - 285
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    The possible limitation in the number of long distance radio stations simultaneously in operation is considered. It is shown how high-speed transmission, improved directional selectivity, and better frequency selectivity would greatly increase the number of feasible co-existent stations, The utilization of a wave length band as a result of high-speed transmission is discussed in connection with frequency selectivity. The 200-kilowatt alternator station at New Brunswick is described, special mention being made of the constant speed regulation system for the induction motor drive, the functioning of the magnetic amplifier, and the operation of the multiple antenna. In this latter connection, the possibilities of effective directional radiation are considered. View full abstract»

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  • Measurement of the electromagnetic field of waves received during trans-oceanic radio transmission

    Page(s): 286 - 296
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    A series of recent experiments is described on the determination of the electric and magnetic field intensities of the waves received at Leghorn, Italy, from the Annapolis, Maryland transmitting station. A pair of large loops, respectively practically parallel and perpendicular to the incoming wave are used. The incoming signals are received by hetero-dyne oscillator and amplified. The substitution method is used for the measurements, whereby the incoming signal is compared to an artificial signal produced in the non-receptive loop by a local oscillator. A thermo-couple and galvanometer in the oscillator circuit, together with a calibrated mutual inductance for coupling to the non-receptive antenna, permit quantitative results. The necessary precautions and procedure are described. Numerical results are given, and it is shown that the field strengths of the incoming waves are much greater than those calculated by the usual transmission formulas. View full abstract»

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  • Discussion [of "Measurement of the electromagnetic field of waves received during trans-oceanic radio transmission"]

    Page(s): 297 - 298
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    For the further progress of transmission theory it is imperative that a large amount of quantitative data be gathered in different parts of the world, especially on signals coming from great distances. It has become increasingly plain that no single formula can represent the experimental facts correctly at all times. There are factors active in transmission which produce such variations in signals travelling more than two thousand miles (3,200 km.), that on certain days the signals produce current in the receiving antenna in Washington more than fifty times the strength produced on the weakest days. While the original author's method of measurement is rather complicated, all the observations and necessary precautions appear to have been taken with the greatest care. The only improvement which I can suggest would be a further check on the calibration of the receiving system by sending with a small known antenna current from a portable antenna or loop at a distance of one or two wave lengths from the receiving station. At this distance and with the long wave length used, absorption would not be appreciable, and all the constants and the distance being known, the original calibration could be verified with considerable certainty. View full abstract»

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  • Radio direction changes and variations of audibility

    Page(s): 299 - 323
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    As a result of a large number of systematic measurements on direction of incoming signals, using loop reception, variations of considerable magnitude in the apparent direction and occurring within short periods of time are found. Their dependence on length and character of wave are studied. There are certain possible theories of transmission proposed to account for the observed phenomena, notably reflection at the atmospheric "isothermal layer" (6.2 miles or 10 kilometers high), and the production of rotating fields at the receiving station. View full abstract»

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  • Discussion [of "radio direction changes and variations of audibility," with author's reply]

    Page(s): 324 - 325
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    It appears that all of the loops experimented with in the original work were of the same form as that described in the paper which gave an asymmetrical polar curve for its directional characteristic. Accordingly, commentor Israel suggests a possible source of error in the experiments, which would lead to a different explanation of the variations in wave direction from any so far advanced. In replying the original author (Kinsley) says in conclusion that the method of measurement correctly showed the variations in directions and the large variations noted were almost always of short duration and came most frequently from midnight to 4 am. It is not likely that a single observer would be ready to note them. Only by continuous measurements over long periods of time was it possible to obtain the results reported in this paper. View full abstract»

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  • Note on Radio Frequency Measurements

    Page(s): 326 - 333
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    After discussing the need for a radio frequency bridge of general utility, the bridge method is critically compared with indicating, null, and potentiometer methods. Certain precautions in the shielding and coil construction of such bridges are considered; and the specific form of bridge used by the author is described in detail. Beat note with amplification and telephone indicator of balance point are used. Some applications of the bridge are then given. View full abstract»

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  • Note on the Input Impedance of Vacuum Tubes at Radio Frequency

    Page(s): 334 - 339
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    It is shown experimentally that the input impedance of a three-element vacuum tube at radio frequency is not infinite, as heretofore supposed, but that because of the capacitive coupling between input and output circuits within the tube itself, the input impedance greatly depends on the character of the output circuit. Experiments with resistance in the output circuit are given and a theory is advanced to explain the results observed. The general effect of inductive and capacitive output circuits is mentioned. View full abstract»

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  • Discussion

    Page(s): 340 - 341
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Aims & Scope

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

Full Aims & Scope