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Show I DISTANCE AND SIGNAL STRENGTH DEPEND ON I flj HEIGHT OF ANTENNA, RADIO EXPERT ASSERTS I By PAUL P. r;onL.FY iAmrlc-a's 1'orcniost Kudlo Authority wjfik I In a receiving antenna it is height fflBU .that couni jjr i Of course, there are other consider- ntions. too. but for the man who wants .to gt signals from great ilistances inn. I what radio flan iiocsn't") height Ms tbe thing for which to strive. 'Xk i Tn0 h'ger ,he antanai ,hc greater the electrical potentials which will bo T '' (produced In it hy the electric waves. '!&' ' The major of the "other consider- jaf'.j 'tiuons" is "nc having to do with res- ; onance. When an electrical circuit si Mfflg j resonant with another electrical clr- jrftf 1 M'jt, It is of such dimension n.s to be capable of having set up in it electri-vffifif electri-vffifif oecilltitioiiH. In order that tins ' 11iav be accomplished by the methods available for tuning the radio receivers, receiv-ers, Bomo thought must bo given to the total length of the antenna a well it a.s its height. Most radio far wish to listen to I t;ivc lengths as short as 200 meters. VvV J jt is much easier to 'load" a small antenna for the reception of long waves than to operate upon a long an-lenna an-lenna for receiving short waves. It Is well to keep this in mind when con-unietlng con-unietlng the antenna. RULiES FOR kERIALS. A gooii rule, although one which - gives onlj spproxli itlona is: ri ; "The total over-all length of the antenna system In feet from It extreme ex-treme end to the ground conoctlon, I IT VERTICAL TYPE A JfeljEE) TWO TYPES ! 1 WTEN N V should not be grektci than the wave j length in meters, divided by 1.2." j Following out this rule. and as-isumlng as-isumlng that it is desired to receive Ifrom stationstransmlttlng at a wavt:. ! length of 200 meters, tho result WlH 'be lfi6 feet. Neither the number of wires In the antenna, nor the height, will bffeel this approximation to any great degree. If it Is possible to secure a non- conductive support as higU as 166 feet, to the top of, which can bo run a vortical, vor-tical, or nearly vertical, Wire or two. thi results will be considerably super- j lor to those obtained from the samel length wire placed In the form of nn "Li" or "T"-shaped antenna, whose vertical sections are only 30 or 40 feet: in length. Put the average radio fan will no' have available supports as high as this. Some may take sufficient Interest in the radiophone to erect a special non-conductive mast, or Insulated ma t, : approximately this height To such, It can be said that the. results j obtained wllf warrant the effort. To those who. must place deprnd-ehe'e deprnd-ehe'e upon what natural supports are! available, it maty b pointed out that the higher the wire, the better, provided pro-vided that th" total length of the an- tenna from Its extreme end to th earth connections, does not exceed th". figure derived from using the formula I given above. Tf the antenna is of too great length, no success is to be had In tuning tun-ing It to the shorter wave lengths. Gains that might result from in- j creased lcngthn are more than offset by loss of advantages due to tuning. |