. Practical wireless telegraphy; a complete text book for students of radio communication . c discharges is employed. Various local appliances have been devised to overcome the interference of static, butnone have been so far highly successful. Balancing circuits have been devised by theMarconi Company with which they .have achieved good results (described in followingparagraph). With ordinary receiving apparatus, the operator, at any given radio station, maypartially reduce static interference by employing the least possible degree of coupling be-tween the primary and secondary windings of th
. Practical wireless telegraphy; a complete text book for students of radio communication . c discharges is employed. Various local appliances have been devised to overcome the interference of static, butnone have been so far highly successful. Balancing circuits have been devised by theMarconi Company with which they .have achieved good results (described in followingparagraph). With ordinary receiving apparatus, the operator, at any given radio station, maypartially reduce static interference by employing the least possible degree of coupling be-tween the primary and secondary windings of the receiving tuner, the respective windingsbeing mechanically drawn apart to a distance consistent with the strength of signals in thehead telephones. Occasionally static interference can be minimized! by throwing the primaryand secondary circuits out of resonance or in case a carborundum rectifier is employed asthe detector, by the application of an abnormal local E. M. F. With sensitive receiving apparatus, such as the repeating three-element oscilla- 172 PRACTICAL WIRELESS Fig. 198—Circuits of Marconis Balanced CrystalReceiver. (English Marconi Company.) tion valve or the step-up valve amplifier, the static signals are enormouslyamplified and the good effects of these receivers are aften thus when atmospheric electricity is especially severe, radio traffic may be morereadily dispatched from station to station by means of a less sensitive receivingdetector, such as the carborundum rectifier or by the Marconi magnetic detector. An interesting aspect of the staticinterference is the fact that it doesnot persist at certain months of theyear in certain localities, being strongfor a period of several days and thensometimes disappearing for a spaceof a week or more. This may be fol-lowed by a period of several days,during which the interference fromthis source is exceptionally strong,but, as stated previously, the highpitched note of modern transmittersto
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
