Pub Date : 1938-03-01DOI: 10.1109/JRPROC.1938.228126
P. Ware
A sliding-contact variable inductance is described wherein contact reliability over long life is secured by a unique carriage arrangement and parallel nibs at the point of contact. The coil is rotatable, the high-potential contact being taken off a ring at one end. The contactor and unused end of the coil are at ground potential. The entire variable coil is used and the high-frequency limit is determined by a separate adjustable "end" inductance which improves the performance throughout the high-frequency range. The high-frequency limit of a continuous operating range for a given coil is near the natural frequency of the unused part of the coil when the contact is near the high-potential end of its travel. Wide frequency tuning ratios of the order of six to eight are feasible and all-wave continuous coverage may be effected with two switch positions instead of three as required with variable-condenser tuning. Oscillator circuits are described which yield substantially uniform voltage over a ten-to-one frequency range. This widerange characteristic may be obtained even in the ultra-high-frequency region. Wider ranges necessitate improvement in the tracking of the usual superheterodyne input circuit. A method for producing a fourth tracking crossover when the inductive tuner is designed for superheterodyne circuit tuning is described.
{"title":"A New System of Inductive Tuning","authors":"P. Ware","doi":"10.1109/JRPROC.1938.228126","DOIUrl":"https://doi.org/10.1109/JRPROC.1938.228126","url":null,"abstract":"A sliding-contact variable inductance is described wherein contact reliability over long life is secured by a unique carriage arrangement and parallel nibs at the point of contact. The coil is rotatable, the high-potential contact being taken off a ring at one end. The contactor and unused end of the coil are at ground potential. The entire variable coil is used and the high-frequency limit is determined by a separate adjustable \"end\" inductance which improves the performance throughout the high-frequency range. The high-frequency limit of a continuous operating range for a given coil is near the natural frequency of the unused part of the coil when the contact is near the high-potential end of its travel. Wide frequency tuning ratios of the order of six to eight are feasible and all-wave continuous coverage may be effected with two switch positions instead of three as required with variable-condenser tuning. Oscillator circuits are described which yield substantially uniform voltage over a ten-to-one frequency range. This widerange characteristic may be obtained even in the ultra-high-frequency region. Wider ranges necessitate improvement in the tracking of the usual superheterodyne input circuit. A method for producing a fourth tracking crossover when the inductive tuner is designed for superheterodyne circuit tuning is described.","PeriodicalId":54574,"journal":{"name":"Proceedings of the Institute of Radio Engineers","volume":"26 1","pages":"308-320"},"PeriodicalIF":0.0,"publicationDate":"1938-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/JRPROC.1938.228126","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62307604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1938-03-01DOI: 10.1109/JRPROC.1938.228189
R. Lambert
The superposition integral is used to express the voltage produced in the inductance of a tuned circuit in response to a voltage impulse of exponential form. The expression is given in terms of the voltage and time constant of the impulse and the frequency and decrement of the oscillating circuit. This method is more direct and more easily manageable than the conventional method which expresses the relations in terms of the current produced in the secondary or oscillating circuit in terms of the voltage applied to this circuit by the primary or exciting source. The conventional equation, Ldi/dt+Ri+q/C=E may be quite troublesome with certain forms of voltage E. Comparisons are made between oscillograms of an experimental circuit and curves calculated from theory. A simple graphical method is given for determining the constants of an exponential impulse from the response curve and known constants of the oscillating circuit. General conclusions are drawn which are of interest relative to radio interference.
{"title":"Relations Existing between Voltage Impulses of Exponential Form and the Response of an Oscillating Circuit","authors":"R. Lambert","doi":"10.1109/JRPROC.1938.228189","DOIUrl":"https://doi.org/10.1109/JRPROC.1938.228189","url":null,"abstract":"The superposition integral is used to express the voltage produced in the inductance of a tuned circuit in response to a voltage impulse of exponential form. The expression is given in terms of the voltage and time constant of the impulse and the frequency and decrement of the oscillating circuit. This method is more direct and more easily manageable than the conventional method which expresses the relations in terms of the current produced in the secondary or oscillating circuit in terms of the voltage applied to this circuit by the primary or exciting source. The conventional equation, Ldi/dt+Ri+q/C=E may be quite troublesome with certain forms of voltage E. Comparisons are made between oscillograms of an experimental circuit and curves calculated from theory. A simple graphical method is given for determining the constants of an exponential impulse from the response curve and known constants of the oscillating circuit. General conclusions are drawn which are of interest relative to radio interference.","PeriodicalId":54574,"journal":{"name":"Proceedings of the Institute of Radio Engineers","volume":"388 1","pages":"372-378"},"PeriodicalIF":0.0,"publicationDate":"1938-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/JRPROC.1938.228189","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62307537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1938-03-01DOI: 10.1109/JRPROC.1938.228190
T. R. Gilliland, S. S. Kirby, N. Smith, S. E. Reymer
Data on the ordinary-wave critical frequencies and virtual heights of the ionospheric layers are presented for the period indicated in the title. The monthly average values of the maximum usable frequencies for undisturbed days, for radio transmission by way of the regular layers is also provided.
{"title":"Characteristics of the Ionosphere at Washington, D.C., January, 1938","authors":"T. R. Gilliland, S. S. Kirby, N. Smith, S. E. Reymer","doi":"10.1109/JRPROC.1938.228190","DOIUrl":"https://doi.org/10.1109/JRPROC.1938.228190","url":null,"abstract":"Data on the ordinary-wave critical frequencies and virtual heights of the ionospheric layers are presented for the period indicated in the title. The monthly average values of the maximum usable frequencies for undisturbed days, for radio transmission by way of the regular layers is also provided.","PeriodicalId":54574,"journal":{"name":"Proceedings of the Institute of Radio Engineers","volume":"26 1","pages":"379-382"},"PeriodicalIF":0.0,"publicationDate":"1938-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/JRPROC.1938.228190","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62307552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1938-02-01DOI: 10.1109/JRPROC.1938.228288
T. R. Gilliland, S. S. Kirby, N. Smith, S. E. Reymer
Data on the ordinary-wave critical frequencies and virtual heights of the ionospheric layers are presented for the period indicated in the title. The monthly average values of the maximum usable frequencies for undisturbed days, for radio transmission by way of the regular layers is also provided.
{"title":"Characteristics of the Ionosphere at Washington, D.C., December, 1937","authors":"T. R. Gilliland, S. S. Kirby, N. Smith, S. E. Reymer","doi":"10.1109/JRPROC.1938.228288","DOIUrl":"https://doi.org/10.1109/JRPROC.1938.228288","url":null,"abstract":"Data on the ordinary-wave critical frequencies and virtual heights of the ionospheric layers are presented for the period indicated in the title. The monthly average values of the maximum usable frequencies for undisturbed days, for radio transmission by way of the regular layers is also provided.","PeriodicalId":54574,"journal":{"name":"Proceedings of the Institute of Radio Engineers","volume":"26 1","pages":"236-239"},"PeriodicalIF":0.0,"publicationDate":"1938-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/JRPROC.1938.228288","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62307508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1938-02-01DOI: 10.1109/JRPROC.1938.228370
G.H. Fritzinger
This paper deals with the application of feedback to amplifiers for the sole purpose of obtaining a frequency discrimination in the gain-frequency characteristic of the amplifier. The theory of the feed-back amplifier is given and the general form of the vector envelope μβ representing the over-all propagation factor of the amplifier and feed-back circuit is described for a feed-back amplifier which is to have a predetermined gain-frequency characteristic. A basis of feed-back amplifier design is indicated in which the desired over-all μβ-vector envelope is formed by choosing and synthesizing the propagation factors of the component circuits in the amplifier and feed-back circuits. The analysis of the amplifier and feed-back circuits into component circuits which have either fixed- or variable-frequency propagation factors is indicated. Various common resistance-capacitance circuit configurations useful in feed-back amplifier design are shown and simple graphical means for determining the propagation-factor-vector envelopes for these circuits are illustrated. The allocation of the frequency scale on these vector envelopes is also done by graphical means. Two specific cases in feed-back amplifier design are then illustrated for obtaining respectively a high-pass and low-pass gain-frequency characteristic to resistance-capacitance-coupled amplifiers utilizing only resistive and capacitive elements in the feed-back circuit. The amplifier circuit arrangements, the μβ-vector envelopes, and the gain-frequency characteristics of the feed-back amplifiers are given in these illustrated cases. The analytical proof for the graphical determination of the behavior of the propagation factor for one of the resistance-capacitance circuits illustrated is submitted in the Appendix.
{"title":"Frequency Discrimination by Inverse Feedback","authors":"G.H. Fritzinger","doi":"10.1109/JRPROC.1938.228370","DOIUrl":"https://doi.org/10.1109/JRPROC.1938.228370","url":null,"abstract":"This paper deals with the application of feedback to amplifiers for the sole purpose of obtaining a frequency discrimination in the gain-frequency characteristic of the amplifier. The theory of the feed-back amplifier is given and the general form of the vector envelope μβ representing the over-all propagation factor of the amplifier and feed-back circuit is described for a feed-back amplifier which is to have a predetermined gain-frequency characteristic. A basis of feed-back amplifier design is indicated in which the desired over-all μβ-vector envelope is formed by choosing and synthesizing the propagation factors of the component circuits in the amplifier and feed-back circuits. The analysis of the amplifier and feed-back circuits into component circuits which have either fixed- or variable-frequency propagation factors is indicated. Various common resistance-capacitance circuit configurations useful in feed-back amplifier design are shown and simple graphical means for determining the propagation-factor-vector envelopes for these circuits are illustrated. The allocation of the frequency scale on these vector envelopes is also done by graphical means. Two specific cases in feed-back amplifier design are then illustrated for obtaining respectively a high-pass and low-pass gain-frequency characteristic to resistance-capacitance-coupled amplifiers utilizing only resistive and capacitive elements in the feed-back circuit. The amplifier circuit arrangements, the μβ-vector envelopes, and the gain-frequency characteristics of the feed-back amplifiers are given in these illustrated cases. The analytical proof for the graphical determination of the behavior of the propagation factor for one of the resistance-capacitance circuits illustrated is submitted in the Appendix.","PeriodicalId":54574,"journal":{"name":"Proceedings of the Institute of Radio Engineers","volume":"26 1","pages":"207-225"},"PeriodicalIF":0.0,"publicationDate":"1938-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/JRPROC.1938.228370","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62308193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1938-02-01DOI: 10.1109/JRPROC.1938.228286
O. Schade
The general characteristics of the ideal output tube for broadcast receivers are discussed briefly with respect to specific electrical and acoustical requirements. Considerations of practical power-tube design indicate that the tube most nearly approaching the ideal characteristics is one having an accelerating grid (screen) and a control grid which does not require power. The limitations of conventional output tetrodes and pentodes with respect to the ideal are treated and are illustrated by means of oscillograms and models showing field-potential distributions. It follows that homogeneous potential fields and directed electron beams having high electron density can be utilized to minimize these limitations. These design features indicate the feasibility of a tube suitable for operation as a class A amplifier having substantially second-harmonic distortion only and capable of high power output, high efficiency, and high power sensitivity. The theoretically proper geometric structure for beam power tubes is developed. The theory is substantiated by performance data obtained from actual tubes.
{"title":"Beam Power Tubes","authors":"O. Schade","doi":"10.1109/JRPROC.1938.228286","DOIUrl":"https://doi.org/10.1109/JRPROC.1938.228286","url":null,"abstract":"The general characteristics of the ideal output tube for broadcast receivers are discussed briefly with respect to specific electrical and acoustical requirements. Considerations of practical power-tube design indicate that the tube most nearly approaching the ideal characteristics is one having an accelerating grid (screen) and a control grid which does not require power. The limitations of conventional output tetrodes and pentodes with respect to the ideal are treated and are illustrated by means of oscillograms and models showing field-potential distributions. It follows that homogeneous potential fields and directed electron beams having high electron density can be utilized to minimize these limitations. These design features indicate the feasibility of a tube suitable for operation as a class A amplifier having substantially second-harmonic distortion only and capable of high power output, high efficiency, and high power sensitivity. The theoretically proper geometric structure for beam power tubes is developed. The theory is substantiated by performance data obtained from actual tubes.","PeriodicalId":54574,"journal":{"name":"Proceedings of the Institute of Radio Engineers","volume":"26 1","pages":"137-181"},"PeriodicalIF":0.0,"publicationDate":"1938-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/JRPROC.1938.228286","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62307454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1938-02-01DOI: 10.1109/JRPROC.1938.228287
H. H. Scott
This paper describes the use of the inverse feed-back principle to obtain sharply selective circuits. Important advantages of such circuits are (1) inductances are not necessary, (2) "tuning" may be changed by merely varying resistances, (3) ready adaptability for use at very low frequencies, (4) "tuning" may be varied over wide ranges of frequency while maintaining a selectivity curve which is a constant percentage function of the tuned frequency, (5) the possibility of using a single set of frequency-determining elements for "tuning" several amplifying stages, and (6) the general simplicity of construction and operation when compared with many other types of equipment designed to produce equivalent results. Many uses for a circuit of this type immediately suggest themselves. Two important applications are described, including a novel type of analyzer and an oscillator having extremely good wave form.
{"title":"A New Type of Selective Circuit and Some Applications","authors":"H. H. Scott","doi":"10.1109/JRPROC.1938.228287","DOIUrl":"https://doi.org/10.1109/JRPROC.1938.228287","url":null,"abstract":"This paper describes the use of the inverse feed-back principle to obtain sharply selective circuits. Important advantages of such circuits are (1) inductances are not necessary, (2) \"tuning\" may be changed by merely varying resistances, (3) ready adaptability for use at very low frequencies, (4) \"tuning\" may be varied over wide ranges of frequency while maintaining a selectivity curve which is a constant percentage function of the tuned frequency, (5) the possibility of using a single set of frequency-determining elements for \"tuning\" several amplifying stages, and (6) the general simplicity of construction and operation when compared with many other types of equipment designed to produce equivalent results. Many uses for a circuit of this type immediately suggest themselves. Two important applications are described, including a novel type of analyzer and an oscillator having extremely good wave form.","PeriodicalId":54574,"journal":{"name":"Proceedings of the Institute of Radio Engineers","volume":"26 1","pages":"226-235"},"PeriodicalIF":0.0,"publicationDate":"1938-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/JRPROC.1938.228287","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62307498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1938-02-01DOI: 10.1109/JRPROC.1938.228369
N. Koomans
An historical introduction reviews the initial long-wave telegraph circuit with the East Indies in 1923, the first short-wave telegraph circuit in 1925, and the inauguration of short-wave telephony in 1928, this being accomplished by means of the usual double-side-band and carrier system. The principal limitations attending this method of operation are discussed; viz., the phenomena of fading, susceptibility to frequency and phase modulation, and the fact that it does not lend itself to multiplexing, because of the presence of the high-powered carrier. The features which characterize the present system are, first, that of single-side-band as applied to high-frequency transmission, and, second, that of multiplexing, whereby a plurality of channels are enabled to be transmitted by means of a single power amplifier and directive antenna system. In the transmitter the group of channels which is to be transmitted, representing one telegraph and two telephone messages, is assembled at low power and low carrier frequency and is then stepped up in power and in frequency in a succession of stages. The spectrum transmitted comprises (1) the two telephone channels located in frequency as single bands on opposite sides of the suppressed carrier; (2) the telegraph channel superimposed thereon as two tone frequencies, one for spacing and one for marking, and transmitted on a double-side-band basis to obtain the advantage of frequency diversity; and (3) the pilot channel transmitted at a frequency 5000 cycles removed from the carrier position.
{"title":"Single-Side-Band Telephony Applied to the Radio Link between the Netherlands and the Netherlands East Indies","authors":"N. Koomans","doi":"10.1109/JRPROC.1938.228369","DOIUrl":"https://doi.org/10.1109/JRPROC.1938.228369","url":null,"abstract":"An historical introduction reviews the initial long-wave telegraph circuit with the East Indies in 1923, the first short-wave telegraph circuit in 1925, and the inauguration of short-wave telephony in 1928, this being accomplished by means of the usual double-side-band and carrier system. The principal limitations attending this method of operation are discussed; viz., the phenomena of fading, susceptibility to frequency and phase modulation, and the fact that it does not lend itself to multiplexing, because of the presence of the high-powered carrier. The features which characterize the present system are, first, that of single-side-band as applied to high-frequency transmission, and, second, that of multiplexing, whereby a plurality of channels are enabled to be transmitted by means of a single power amplifier and directive antenna system. In the transmitter the group of channels which is to be transmitted, representing one telegraph and two telephone messages, is assembled at low power and low carrier frequency and is then stepped up in power and in frequency in a succession of stages. The spectrum transmitted comprises (1) the two telephone channels located in frequency as single bands on opposite sides of the suppressed carrier; (2) the telegraph channel superimposed thereon as two tone frequencies, one for spacing and one for marking, and transmitted on a double-side-band basis to obtain the advantage of frequency diversity; and (3) the pilot channel transmitted at a frequency 5000 cycles removed from the carrier position.","PeriodicalId":54574,"journal":{"name":"Proceedings of the Institute of Radio Engineers","volume":"26 1","pages":"182-206"},"PeriodicalIF":0.0,"publicationDate":"1938-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/JRPROC.1938.228369","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62308180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1938-01-01DOI: 10.1109/jrproc.1936.227370
Provides a list of recent commercial literature received by the Institute.
提供研究所最近收到的商业文献清单。
{"title":"Booklets, catalogs and pamphlets received","authors":"","doi":"10.1109/jrproc.1936.227370","DOIUrl":"https://doi.org/10.1109/jrproc.1936.227370","url":null,"abstract":"Provides a list of recent commercial literature received by the Institute.","PeriodicalId":54574,"journal":{"name":"Proceedings of the Institute of Radio Engineers","volume":"26 1","pages":"788-789"},"PeriodicalIF":0.0,"publicationDate":"1938-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/jrproc.1936.227370","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62305128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1938-01-01DOI: 10.1109/jrproc.1936.228026
Provides a list of recent commercial literature received by the Institute.
提供研究所最近收到的商业文献清单。
{"title":"Booklets, catalogs and pamphlets received","authors":"","doi":"10.1109/jrproc.1936.228026","DOIUrl":"https://doi.org/10.1109/jrproc.1936.228026","url":null,"abstract":"Provides a list of recent commercial literature received by the Institute.","PeriodicalId":54574,"journal":{"name":"Proceedings of the Institute of Radio Engineers","volume":"26 1","pages":"914-914"},"PeriodicalIF":0.0,"publicationDate":"1938-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/jrproc.1936.228026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62305638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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