Show 1 I 37 by G hu AND HOW ATTAINED by ARMSTRONG PERRY I 1 w i of the first words a 0 beginner life when ho he starts to shop around selectivity 1 act avit y it nay may be att attracted by the simplic ba a price of a cabinet on which aro are latho two or three knobs to adjust and r ij if it will bric bring ig tn in the concerts mixtures pictures from di distant stations he ld d that it will but that the cabinet biffl five or six knobs on it which ni j do CO or per cent inore har affer er selectivity agbe la inquisitive als itie ho w complicated kunf I 1 Al opler one TI arthe simpler simple r one sAre i A V 7 1 opt 4 za to W TI Q ap ami dow MIS haw 71 J Q era i and that a single circuit using r inductance colls climen condensers sera and er parts than a two e cannot be tuned as sharply as ar 0 one ne using more p parts arts means the ability to pick t the station you want to hear to lve veone one station without by others it can be obtained I 1 at the expense of high class en aring a ang and the use of many parts ats money to build a selective set the person of unselective tempera enjoys having a lot of things goin in atthe same time ho he will get anent and profit out of a radio ret iver that will not narrow itself down 11 single station the higher grade eur on the other hand wants to able ble to bring in the weakest most fallt nt station and he la Is impatient er the slightest interference so bo it UP to the beginner to decide just at he will expect of the receiving be e wants efte me of the circuits and general beup ap of selective receiving sets are gifted rated he here e figure I 1 shows a r selective tuner for use with a stal al detector 0 greater reater selectivity Is ned aided by shunting the tuning coll coil a 4 43 plate variable condenser re FB 2 shows a single circuit it tuner tiner kap IP that will give fair select W if 1 the two variable con tre N shown are used A vernier verniel assist greatly if used in connect with alth the variable condenser shunt oss the tickler figure 8 3 shows to ID obtain tain greater select selectivity than ahad faoro the set shown in fig two wo vario varlo meters may be added ns shown The variable condenser la Is not absolutely necessary but Is advantageous vant ageous for sharp tuning figure 4 shows how a super selective tuner may be rondo by connecting two varlo cou piers ind and a this set allows the operator to tuno tune out unwanted signals completely and bring in those desired with a maxtin maximum uin vol volume time selectivity to Is a great principle it applies not only to radio but to all human relationships are till all different and we act 1 it things kill at Is 18 fur boota jj ta ren for t the fie down jit tl h conte P v ichi iwho who sea tokuya to taj huya 1 h in pa single at circuit tuner nor for the user of the abores aforesaid tuner to look down upon the man who alkes i to specialize on long distance messages nies sages it Is un unfortunate fortuna to for the boy who has ha shown has jio no special aptitude in te technical pastimes to follow the lead ot of 11 the technical radio amateur for or ho he will aly ma k a a nuisance of hlin and accomplish nothing it t Is equally unfortunate for api folks ks who 1 merely listen ln in wit alth h a radio set for the anke sake of amelse CP t to complain of a boy who has earned ills his money for the parts bl built illi his radio set ant and who if he la Is encouraged may build upon the foundation laid by such men as hertz marconi fleming der deforest orest armstrong Du dubilier biller Well gant and steinmetz apparatus find organizations that will advance civilization a hundred years inside of 0 decade selectivity it if it isto Is 10 be intelli intelligently gentl y accomplished must depend upon a knowledge of the things from which the selection 16 made the beginner who selects a radio receiver no matter how simple so long as it will bring in something and who listens carefully and thoughtfully da day y after day with a view to learning something and making maka progress a may become either a tech iii etil radio amateur or merely one of lie maJori majority fy who use radio with increasing effi efficiency clency to bring to their h home owe music lectures sermons and ther other food for the mind and soul in eliher either case if he Is fair minded lind and generous ene roua lie he will never lack a sympathetic ap understanding of the other amateurs ambitions and problems Q science helene a and invention |