. An elementary manual of radiotelegraphy and radiotelephony for students and operators . sed circuit antenna^, and the radiationwill then be a maximum in the direciiun iu which that primarycoil points. Experiments with this system sliowed that good results couldbe obtained with an expenditure of less than 500 watts betweenDieppe and Havre (55 miles overland) and Dieppe and lUirtleur(110 miles over sea). Tho angles between the stations, Dieppe-Ilavre-Barfleur is 23, but the Dieppo-Barfleur transmission did 192 RADIO TELEGRAPHY not affect the Havre, nor did the Dieppe-Havre transmission affectB
. An elementary manual of radiotelegraphy and radiotelephony for students and operators . sed circuit antenna^, and the radiationwill then be a maximum in the direciiun iu which that primarycoil points. Experiments with this system sliowed that good results couldbe obtained with an expenditure of less than 500 watts betweenDieppe and Havre (55 miles overland) and Dieppe and lUirtleur(110 miles over sea). Tho angles between the stations, Dieppe-Ilavre-Barfleur is 23, but the Dieppo-Barfleur transmission did 192 RADIO TELEGRAPHY not affect the Havre, nor did the Dieppe-Havre transmission affectBarfleur. The height of the antenna? was 48 metres, the wiresbeing 60 metres long at the base and 60 long in the inclined side,forming an equilateral triangle, each side of which was 60 metresin length. It was also found that this closed circuit system wasmore proof against disturbances from atmospheric electricity(to which further allusions will be made in Chapter VII.) than thesystem employing open circuit antenna3. The great advantage of the methods of Bellini and Tosi is ^vCROWArr^. Htproiwxi froyn. Mectrical Engineering by permission of the proprietorsFig. 3i. that no movement of the antennse themselves is required to locatethe direction of the radiant centre or to give direction to theradiation. The only movable part is a small coil which acts upon,or is acted upon, by the fixed antennse. This arrangement forlocating the direction of a station is called a radiogoniometer byits inventors, and promises to be of considerable use in connectionwith radiotelegraphy. By employing a single vertical antenna incombination with two nearly closed antennae at right angles toeach other (see Fig. 33), Bellini and Tosi have been able to confinethe radiation of this compound antenna entirely to one side; sothat the polar curve of radiation is represented by a cardiod(see Fig. 34), the antenna being situated at the cusp. It may be noted also that A. Artom had previously employedbent antenns
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1916
