Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication最新文献

Pulse communication on lines 线路脉冲通信

Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication Pub Date : 1947-12-01 DOI: 10.1049/JI-3A-2.1947.0058

S. Moss, G. Parks

{"title":"Pulse communication on lines","authors":"S. Moss, G. Parks","doi":"10.1049/JI-3A-2.1947.0058","DOIUrl":"https://doi.org/10.1049/JI-3A-2.1947.0058","url":null,"abstract":"A dispersive medium, i.e. one in which the waveform of an individual pulse changes its type at successive points during propagation, is not normally appropriate for pulse communication, since greater efficiency can be achieved through it in other ways. However, conditions can arise in which it becomes desirable to employ such a link, and it is necessary to discover the restrictions imposed by the medium on multichannel pulse communication, and the steps that can be taken to minimize these limitations.The paper briefly describes a theoretical and experimental investigation by the authors into the particular problems of pulse communication over a 50-mile open-wire line of the standard Army type. The major problem, of adjacent-channel interference caused by the progressive deterioration of the individual propagated pulse waveforms to a point where they appreciably overlap, is adequately solved by adapting and extending a technique employed for wide pulses in line telegraphy to the case of narrow pulses. This is the device of reducing the interfering effect of each trailing pulse response by transmitting, instead of a simple rectangular pulse, a controllable curbed pulse, i.e. a flexible combination of contiguous pulses of opposite sign. By this means satisfactory crosstalk results are achieved for multichannel pulse operation in one direction.For two-way operation the dominant problem now becomes the near-end interference arising from the irregular sequence of pulse reflections from various inhomogeneities in the line. Unless the line is sufficiently smooth, the crosstalk so occasioned may become intolerable.","PeriodicalId":337607,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication","volume":"212 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121250278","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}

引用次数: 1

Dielectric-rod aerials Dielectric-rod天线

Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication Pub Date : 1947-12-01 DOI: 10.1049/JI-3A-2.1947.0074

D. Halliday, D. Kiely

引用次数: 15

The development of a high-frequency cathode-ray direction-finder for naval use 舰船用高频阴极射线测向仪的研制

Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication Pub Date : 1947-12-01 DOI: 10.1049/JI-3A-2.1947.0102

S. D. Walden, A. Rocke, J. Barrett, W. J. Pitts

{"title":"The development of a high-frequency cathode-ray direction-finder for naval use","authors":"S. D. Walden, A. Rocke, J. Barrett, W. J. Pitts","doi":"10.1049/JI-3A-2.1947.0102","DOIUrl":"https://doi.org/10.1049/JI-3A-2.1947.0102","url":null,"abstract":"The operation of the direction-finder described in this paper is based on the familiar principle by which two balanced amplifiers, connected to Bellini-Tosi crossed loops, operate the appropriate deflecting plates of a cathode-ray tube. The bearing is displayed as a trace on the c.r.t. fluorescent screen, providing a direct instantaneous reading. The sense of the bearing is obtained by combining the signals from an omni-directional sense aerial with the signal from either of the loops. The sense signal modulates the intensity of the electron beam, which is being swept, either vertically or horizontally, by the signal provided by the respective loop. The relative phase of the two signals is such that one or other end of the fluorescent trace is blacked out, depending upon which of the two lobes of the figureof- ight loop characteristic is effective for a given wave-direction.The first experimental equipment, designed for surface vessels, was already in operational use at the end of 1941, but the development proceeded until 1944, when the equipment reached its final form. With small modifications the same equipment was adopted for use at naval shore-stations, operating with an Adcock aerial system.The paper describes the latest design of the shipborne equipment and also discusses, more generally, some of the problems of the twinchannel receiving technique encountered during the development.","PeriodicalId":337607,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124389244","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}

引用次数: 12

Note on a short-range radio position-finding system using modulated continuous waves 注意使用调制连续波的短程无线电定位系统

Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication Pub Date : 1947-12-01 DOI: 10.1049/JI-3A-2.1947.0124

R. F. Cleaver

{"title":"Note on a short-range radio position-finding system using modulated continuous waves","authors":"R. F. Cleaver","doi":"10.1049/JI-3A-2.1947.0124","DOIUrl":"https://doi.org/10.1049/JI-3A-2.1947.0124","url":null,"abstract":"The paper describes a position-finding system by which the polar co-ordinates of any suitably equipped aircraft can be determined at a single base station using phase-comparison range-finding apparatus and a v.h.f. automatic direction-finder in conjunction with conventional communication equipment.‡An experimental model is described in which azimuth and range are displayed on a single cathode-ray oscillograph, which may be installed in an airport control tower. Range is indicated without ambiguity up to 100 nautical miles, and there is no azimuthal ambiguity. So far, the model has been used primarily to demonstrate the principles of the system, in conjunction with an aircraft fitted with an experimentally modified Service type of v.h.f. communication equipment. The results of a limited number of tests suggest that, with airborne equipment specifically designed for use with the system, the probable error in range measurement should be less than 1 mile. Azimuthal accuracy is not here discussed, but in a companion paper it is shown that the probable instrumental error of the direction-finder is less than 1.5 deg, implying a probable lateral error less than 2.5 miles at the maximum non-ambiguous range of 100 nautical miles.","PeriodicalId":337607,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124448214","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}

引用次数: 3

The errors in bearings of a high-frequency direction-finder caused by reradiation from a nearby vertical mast 由附近垂直桅杆的辐射引起的高频测向仪的方位误差

Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication Pub Date : 1947-12-01 DOI: 10.1049/JI-3A-2.1947.0101

C. Crampton, R. Whipple, A. Mugridge

引用次数: 6

Statistical plotting methods for radio direction-finding 无线电测向的统计标绘方法

Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication Pub Date : 1947-12-01 DOI: 10.1049/JI-3A-2.1947.0087

R. H. Barfield

引用次数: 2

An instrument for measuring the resonant frequency of reradiating structures 测量辐射结构共振频率的仪器

Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication Pub Date : 1947-12-01 DOI: 10.1049/JI-3A-2.1947.0094

W. Struszynski, E. G. Robus, J. Woolley

引用次数: 2

Electro-acoustic transducers and intercommunication systems for aircraft 飞机用电声换能器和通信系统

Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication Pub Date : 1947-12-01 DOI: 10.1049/JI-3A-2.1947.0049

W. Makinson

引用次数: 1

An analysis of the performance of multi-aerial Adcock direction-finding systems 多天线Adcock测向系统性能分析

Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication Pub Date : 1947-12-01 DOI: 10.1049/JI-3A-2.1947.0095

P. G. Redgment, W. Struszynski, G. J. Phillips

{"title":"An analysis of the performance of multi-aerial Adcock direction-finding systems","authors":"P. G. Redgment, W. Struszynski, G. J. Phillips","doi":"10.1049/JI-3A-2.1947.0095","DOIUrl":"https://doi.org/10.1049/JI-3A-2.1947.0095","url":null,"abstract":"This paper presents a theoretical discussion of the performance of crossed fixed-aerial Adcock direction-finder systems employing more than two aerial pairs. Comparison is made with the conventional four-aerial Adcock system, with regard to both spacing error and sensitivity.Improvements are obtained by increasing the total number of aerials over the four of the conventional Adcock system, so that, for a given accuracy, a gain may be achieved either in frequency coverage or sensitivity, or in both together. It is also shown that an increase in the number of aerials above eight is of little practical advantage, since the spacing for small errors approaches the absolute limit of 1.22λ.A modified system, in which two aerials are connected in parallel to replace each of the single vertical aerials, is also discussed. This system has a performance nearly as good as the fully symmetrical eight-aerial system, and when used in conjunction with a twin-channel receiver it is expected to give the better performance.Finally it is shown that a star connection of the aerials provides a correct sense signal, only when the aerial spacing is less than 0.76λ.","PeriodicalId":337607,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124641174","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}

引用次数: 6

The omni-directional radial-track guide 全向径向导轨

Journal of the Institution of Electrical Engineers - Part IIIA: Radiocommunication Pub Date : 1947-12-01 DOI: 10.1049/JI-3A-2.1947.0125

J. Ashton, A. Beresford

引用次数: 1