RADIO DEPARTMENT Thn Inltlt uh of E lectrical En glnee... Hertz.-wave theory, by il$ fascinating hold Wllh th e H Igh F l"1Iquency Altern"or Sho..... n In Fig. t. F Ig. 2. to those o f the Ge r man physicist. All my on the imagination, has stifled creative effo rt in the wireless art and retarded it for twcntr-five :rears. But, on the ot her hand, E lect r Ic Tr:tns m lulo n T h ru II S In g le WI,.. Hydraulic An .log. F Ig. 4. r. revious effort, with Rhumkorf (Oils had it is ImpoSSIble to over-estimate the bene- e ft me unconvinced, and in order to set- ficial effects of the powerful stimulus it was the initial !te~ in the evolution o f illY tle my doubts 1 wenl over the whole ground has given in ma ny directions. wirele5s system. The idea preSented itself once more, very carefully, with thcse im- As regards signaling without wires, the to me that it might be possible. under ob- May, 19 19 ELECTRICAL EXPERIMENTER 29 numbe r of radial improvements_ Suitable high frequency generators and dcctricaJ os- cillators had first to be prod~ The energy of these had to be transformed in "w effcct i n~_ transmitters and collcct«l at a distance in proper receivers. Such a sys- IUultratlng T ypical Arrlngemenu for tem would be manifestly cin:umscriJed m CoUectlng E nergy In a SYlum Of Trlnl _ ml..lo n T hru a Sl ngl " Wire. Fig. 5. its usefulnus if all extraneous inlttiuence were: nOt prevented and excJu!; ~­ servance of proper conditions of resonance, to transmit electric energy thru the earth, secured. In time, however. 1 recognUed that devices of this kind, to be most ~«1- th us dispensing with all artificial conductors. £Jnvkd",poci~ £le O'CfaJ~~ Anyone who might wish to examine ilnpartially the me rit of that earlr suggestion must not "iew it in the light 0 present day science. I only need to say that as late as 1893, when I had prepared an elabdr.ue chapter on my wireless system. dwelling on its . 1~~,; F.:;:I r Ta'a's Sya-tem of W lrelen T ranlmlnlo'" Th", th. Earth as Actually Exposed In H I, Lacturet Befor-e th e Frankli n In_ Itltute Ind Electric Light "'"oclatlon In February and Mlrch, 1893, F ig." of a condenser subdidded into small sec· various instrumentalities and future pros- pects, Mr. Joseph Wetzler and other friends of mine emphatically proteSied against its publication on the ground that such idle and far-fetched speculations would ~n)ure me in the opinion of conservative busmcn men. So it came that only a small part of what I had intended to say was embodied in my address of that year before the Franklin Institute and National Electric Liltht Association under the chapter "On Electrical -,;,.,. ,.,~.1lih" ,.."""),!k"'~d' Tr ~n.ml ..lo n Of E lec t rical Energy T hru th" Eart h a. IIlu lt r~ted In Tnla'i Lecture. B". fore the Franl(lIn Inltltute and E I"ct riC L ight Associa t ion In F'bru~rl and March. 1893. and Mec h anical Analog 0 th e Same. FI~. 7. tions. the finer adju5tmrots being dlected by a movable iron core: within an indllct· ance coil. Loosely linked with the latter was a high tension scocmdary which was tuned to the primary. The operation of devicC$ wire without return was punl;,!" because of explained its by novelty, suitabJi!,:_ ,:",.",Iii;~ purpose refere nce ';s In the former the I ive and efficient. should be de:signed with cond uctors are due regard to the physical propertin of this planet and the electrical conditions obtaininc on the: same. I will briefly touch upon the salient ad"ances as they ....ere made in the gradual deve:lopment of the system. The high frequency alterllator employed in my first dellionstrations is illustrated in Fig. 1. It comprised a field ring, with 384 pole projections and a d isc armature with coils wound in one single layer which were: connected in va rious ways according to requirements. It was an excellent machine for experimcntal purposes, furnishing sinu- ...¥ii¥ e" Tho Forerunner of Audlon - the Se n sit iv e Wlteletl Detector Kn ow n. ae Oe · ICrlbed by T.I II In HI, Lecture Before th. Inltltutlon Of E lec tri cal En gl. n. a r l. London, February, 1892. Fi g. II. cta grlm E lucida t Ing Eff"ct of Ll rge Capac_ Ity on One End. Fig. 5. soidal currents of from IO,OClO to 20,000 cycles per s.econd, The output was com- paratively large, due to the fact that as seclion, th e alternator by an oscillating Resonance." This little salvage from the much as 30 amperes per SQuare millimeter piston and the filament of an incandescent wreck has earned me the title of "Father could be past thru the coils without injury. lamp by a minute channel connecting the of the Wire:Jess" from many well-disposed The diag ram in Fig. 2 sh ows the circuit pi pes. It will be clear from a glance at fellow workers, rather than the invention a rrangeme:I\IS as used ill my lecture. Reso- the diagram that "ery slight excursions of Kores of appliances which bave brought nant conditions were maintained by means of the piston would cause the fluid to rush wireless trans- with high ve- mission within locity thru the the reach of small channel every young and that vir· amateur a n d tually all the which. >in a ene r gy of time not dis- movement tant, will lead w ou ld be to undertak- t r a IIsfonned ings overshad· into heat by owing in mag- friction, simi_ nitude and larly to that importance all of the electric past achieve- current in the menu of the lamp filament. engineer. The second The popular diagram will impression is now be self- that my wire· less work was A,(_y ar..€..U..."..a.-PI r 1 8 0 0 ' f : g " _~ "" "'"'"M>d t~ ",bNr~ elastic reserv o ir is em- plo)'C-d which dispenses with the necessity of a return pipe. As the piston oscil- lales the bag expands and Contra cts, and start that the the fluid is successful con summa- '11. 10. made 10 surge thru the re- tion could only stricted pas- be brought Tn la 's Syllem of Co n ca tenate.f T uned Clrcultl Shown ~nd Described tn U. S. P atent No. 568.178 of sagewi thgre:at about by a S"ptember 22. 1896, ard ':orrespondlng .......angementl In Wlrel... Trantml,,'an, speed, thi.", _ __ rc~uhing in the generation of he>t u in the incandesccnt lamp. Thooreticalh- considered, the efficicllcy of conveulon of energy should be the samc in both c",_es, Gralllcd, then, that an economic system of power transmission thru a single wire is ,. , Tcsm four~JI''Cutf tu"ui _,-deu SJU~ • J , Four Ctn;ult Tuned Syltem Con_ W ith th e Contemporanlou , Hertz _ Walll Syltem, Fig. 11. practicable, the question arises how to collett the energy in the receilers. \Vith this object attention is called to Fig. 5, in which a co nducto r is sho\\ n excited by an osdllator jo!ne~ t? it alone end. Evidently, as the penodlc Impulses pa n Ihru th e win~ , uifferellces of potential will be created along th e same as we ll as at right ang les to il in the surrounding medium and either of these may be usefully applied. Thus at a, a circuit comprising an inductance and (3padty is resonantly excited in the t ransverse, and at b, in the longitudinal sense. At c, ener~,'y is collected in a circuit parallel to Ihe conductor but not in contact wilh it, and again at d, in a circuit which is pa rtly sunk into the conductor and may be, or not, electrically connected to the same. It is important to keep these typ ical dispositions in mind. for howel'er the distant ac- Arrangementl Qf D l re ~(I"e Clrc u 1ts Dncrlbed In Tnla', U. S. Patent No. 613,8011 01 NOllember 8. 189l1, on "Method of and Apparatul for Con_ lroiling Mech.nl l m of Moving Vu- ..II or Vehlclet." Fig. 12. lions of the oscil lator might be modified tbm the 'immense extem of the globe the principles involved arc the same. Consider now the effect of such a con- ductor of vast dimellsiOlls on a circuit ex- citing it. The upper diagram of Fig. 6 il- lustrates a familiar oscillating: liystem comprising a slr.light rod of sclf-mductancc 2L with small terminal capacities (( and a node in the center. In the lower diagram of the figure a large capacity C is auached to the rod at one end with the result of shifting the node to the right. thru a distance cor- responding to self-inductance X. As both paru of the s}stem on either side of the + node vibrate at the sallie rate, v,c have c\·i- demly, (L X) c = (L _ X) C from C-, c+, which X = L When the ca- pacily C becomes commen~urate to that of the earth, X approximates L, in other words, the noue is close to the ground con- Ilcction. The I'X(l(/ detr'millPliulI of ils po.dlioll is f.'Uy imparl/lilt {" tilt (01, .. /(1- tian of ct rloin 11"'(,.Ilrilll rlrctrical (llid geodetic dala and I have devised spedaJ means with this purpose in view. ~Iy original plan of tran smitting energy without wires is shown in the upjl('r dia- gram o f Fig. 7, while the lowe r one Dlm- t rates its mechanical ana log, first publisht in my article in the Ct'''''Jr~ A/IJ{jazillt' of Jun e, 1900. An alternator, preferably of high tension, has one of its terminals con- neCled to the ground and the other to an elevated capacrty and impresses its oscil- lations upon the earth. At a distanl point a receiving circuit, likewise connected to ground and to an elevated capacit)', collects some of the energy and actuates a suitable device. I suggested a multiplication of such units in o rder to intensify the effects, an idea which may yet prove \'aluable. In the analog two tuning forks arc provided, one at the sending and the other at the re- ceiving station, each having attached to its lowe r prong a piston fitting in a cylinder. The two cylinders communicate with a large elastic resen·oir filled with an incom- JiI~S21i~,. k:':,'W''/;.:' /:---------'·-·"~-~-',:,->::"::" ~' :. \ f!li/I:! '..\\\\'.\\ ""11':1 1:1i"1)',:1!,1• -._-'-.-""_,., -",.~ .,.:;....,-~4 _ ~ . . . : . . . - - \1. \ \1' .\.1·'·1' \\.;'1' 1' . au ; 0' D iagram E xpol lng the Fail icy th e G liding Walle Th eory .1 P ropounded In Wlrel..1 T ext Bookl. Fig. 11. pressible fluid. The vibr ations transmitted to either of the tuning forks excite them by resonance and, thru electrical contacts or otherwise. bring about the desired re- sult. This, I may say, was not a mere mechanical illustratiOll, but a simple rep- resentation of my apparatus for submarine si/{naling. perfected bf me in 1892, but not appreciated at that time, altho more efficit'nt than the instruments now in use. The electric diagram in Fig. 7, which was reproduced from my lecture. was meant only for the exposition of the prin- ciple. The i'rrangement. as I described it in detail, is shown in Fig. 8. In this case an alternator energizes the primary of a transfonner, the high tension secondary of which is connected to the ground and an dented capacity and tuned to the imprest oscillations. The receiving circuit consists of an inductance connected to the f,:round an d to an elevatcd terminal without brea k and is resonantly responsive to the trans- mitted oscillations. A specific form of re· cciving de"ice was not mentioned, but I had in mind to transform the recei" ed cur· rents and thus make their \'ohlme and ten- sion suitable for any purpose, This, in suustance, is the system of toda~ ;and I a!ll. not awa re of a single auth entical~ instance of successful transmi,sion at eon5iderat~e distance hy different instrumen_ talities. It might, vcrhaps, not be clear to ...; <,\7:,>:'>- \ql;....~ , .-~-.::..--=:::,.~~" :,\ ':,,~,?-,::.-;t /<~:;:;:?= i'~~:::3-<~>" v.',. ' " ' I f " , ' 1 \ \ \ '. 1I ,/,~,-./....'.:--:,..... :.Q.. "" .. " ' \ ' I I I !1-4~ 4q n I , \ I \ I I t I I ,'" I : I 1.,- 'fCln ' i : ' : ,\I I I " !I I I I ! Fig. H. Diagram E xplainIng the Re_ lation Between t he Effectille and the Mea.u~d Curren t In the Antenna. those who have perused my first description of'thcse improvemcnts that, besides making known new and efficient types of apparatus. r gave to the world a wirekss system of potentialities far beyond anything before conceived. I made explicit Q 6 Ifufz (}Self/c/oI' of grwl t!nO!I,Y IneH«''''f Fig. 15. IIIUltraU ng One of the General E III _ dence. Aga ln. t the Space Walle Tranlmlulon. and repeated statements that I contemplat~ transmission, absolutely unlimited as to terrestrial distance and amount of en· ergy. Bm, altho 1 have oveTC{Jme all obstacks which st'emcd in the beginning un· surmountable and fowld elegant solutions of all the problems which confronted me. yet, e,'en at this very day, the majority of experts are stiJI blind to the possibilitiu which arc within easv attainment. ).Iy confidence that a signal could be easily flashed a round the globe waS strengthened thru the discovery of the " rotating brush." a wonderful phenomenon which I have fully dcscri bed in my addreu before the I nstitution of Electrical Engineers. London. in 1892, and which is illustrated in Fig. 9. T his is undoubtedly the most delicate wireless detector known, but for a lo ng time it was hard to produce and to maintain in tht' sensitive state. These difficulties do not exist now and I am looking to valua ble applicat'ions of this device, particularly in connection with the highs~ed photographic method, which I suggested, in wireless, a~ well as in wire, transmission. Possibly Ihe most important advances during the follow';ng three or four years were my system of concatenated tuned ci rcuia Fig. 16. Showlnll Un lmporUnce of Re l.;n·lle Po.ltlon of Tran.mlUlng and Recellling An_ tennae In D llprollal of the Hertz·w.lve Th eo ry. and methods of r egulation, now univer_al_ adopted. The in timate bearing of th e"C :nl'C'ntions on the development of the wirele· art will appear from Fig. 10, which illu-- (COnl;'JUCd 0/1 page (1) May, 19 19 The T rue Wireless By Niko{fJ TU/fJ (ColllilllUd from page 30) tra tes an a rrangement des<:ribed in my U. S. Patent No. 568178 of September 22, 1896, and corresponding dispositions of wireless apparatus. The captions of the individual diagrams are thought sufficiently explicit to dispense with further comment. I will merely remark that in this early record. in addition to indicating how any number of resonant circuits may be linked and regulated, I ha"e shown the advantage of the pro~r timing of primary impnlses and use of ha r monics. In a farClcai wi reless suit in London, some engineers. reckless of their reputation, have claimed that my circuits were not at all attuned; in fact they asserted that I had looked upon resonallce as a sort of wild alld ull tamable beast! It will be of interest to I;ompare my sys- tem as fin! deSl; ribed in a Belgian palent of 1897 with the H ertz-wave system of that period. The signifil;all t diffe rences between them will be observed at a glance. The firs t enables liS to transmit economically energy to ally distance and is o f inestimable value; the latte r is capable o f a radius of ouly a few miles and is worthless. t n the first there are no spark-gaps and the al;tions are C'normously magnifiC'd by resonance. In both transmitter and recei"er the currents are transformed and rendered morc effecti,'e and suitable fo r the operation of any desired de"ice. Properly constructed, my system is safe against static and other interference and the amount of energy which may be trans mitt cd is billiolu of Ii/lit: greater than with the H ertzian which has 1I0ne of these \'irtues, has ne\'e r been used successfully and of which no t race can be found at prese nt. A well-adve rt ised expe rt ga"e out a sta te- ment in 1899 that my apparatus d id not work and tha t it would take 200 yea rs befo re a ml;ssage would be flashed across the Atianl'iI; and he eve n accepted stolidly my congratulations on a supposed great feat. But subsequent exa mi na tion of the reco rds showed tha t my devices were secrt'lly used all the t ime and eve r since I learned o f this I ha ve treated these Borgia-Medici methods .....ith the contempt in .....hich th ey arc held by all fa ir-minded men. T he who lesal e app ro pr ia~iOIl o f my inve nti ons was, how- eve r, no t al ways without a dive rt ing side. A s an example 10 the point I may ment ion my osciilalion transfonner operating wi th an ai r ga p. T his was in tu rn re placed by a carbon are, quenched ga p. an atmosp here o f hydrogen. ar gon o r heliu m. by a me- chanical break .....ith oppositely rotat ing members, a mer cury interrupter or some kind of a vacuum bulb and by such tOllrs de fo~(t as many ne w "systems" ha"e been -produced. I refer to thlS of course. without the slightest ill-feeling, let us ad,'ance by all tn('ans. But I cannot help thinking how much bette r it would ha\'e been if the ingenious men, .....ho have originated these "systems," had 4n\'emfii something of their own instead of de~nding on me altogether. Before 19(X) two mos t "aluable improvements were made. One of tbese was my individualized system wilh tr.lnsmitters emit- ting a wave-.::omplex and recei\'e rs compris- ing s('parate tuned elements eoOperatn'el,y associated. The unde rl ying principle can be explained in a few words. Suppose that there are II simple vibrations swtable for use in wireless tra nsmission, the probability that anyone tnne 'l\'ilI be str uck by an 1 extraneo us distu rbance is - . There will " then r emain 11-1 vibrations and the chance 1 that one of tlleSe will be excited is _ _ , II- I [ .E. hence the probability that two tune$ would be strllck at the same tim e is . Sim- /I ' 1I~1) Harly, for a combina tion of three the chance 1 will be and so on. It will be n ( n-I ) (11-2) read ily seen that in this ma nner a ny desired degree of safety against the statics or other kind of disturbance can be attained pro- vided the Te1:eiving apparatus is so designed that its oper.ttioll is poss ible only Ihru the joint aCiion of all the tutled elcmcnL. This was a difficult problem which I have suc- cessfully solved so that now auy desired mUllb..r of simultalli'ous messages is prac- !icable in the Inmsmi.uioll IIrru the eorlh as wi'll as thrrl artificial rOllductol's. The othe r invention. of still g reater 1mpartance, is a peculiar oscillator enabling the transmission of energy without wires in any quantity that may ever be require!1 for illuustrial use, to any distance, and with very hiGh economy. l t was the ou tcome of years of systematic study and investigation and wonders will be achieved by its means. The prevailing misconception of the mechanism involved in the wireless transmis- sion has been resp-onsible for various unwarranted ;lIlnO\lncements which ha ve misled the public and worked hann. Bv keerJing steadily ill mind that the transmii~iun thru the earth is in every re spect identical to that thm a straight wire, one will gain a clear understanding o f the pheno me lla and wi!! be able to jud~e correctly lhe meri ts of a new scheme. \Vlthout v."; sh- ing to det ract from the value of any plan that has been put forwa rd 1 may say that they a re devoid of llOvelty. So for ins tan ,e in Fig. 12 arrangeme nts of tra nsmittin¥" and re<: ei"ing circuits arc illustrated. whICh I have described in my U. S. Patent No. 613809 of November 8, 1898 011 a 1lethod of and Apparatus for ControUi.ng Mechan- ism of Mol'ing Vessels or Vehicles, and which ha\'e been r ecently di s hed up as original discoveries. I n other patents and tet:h- nical publications I have suggested conductors in the ground as one of the: obvio\1~ modifications indicat ed in Fig. S. F or the sa me reason the statics are slil1 die bane o f lhe wireless. There is aoout as milch vi rtue in the remedies recenth' proposed as in hair·restorers. A .mwll aud compact apparatu.r has b.-nt prodl/crd which does ·au'IlY eulir.-l" witlt tltis trouble at least in plants smiably remodelJcd. ' Xothi ng is mo re impo rtant in the present !)hase of development of the wireless art than to dispose of the dominating erroneous ideas. With this objcct I shal1 advance a few a r~uments ha sed on my own observations which prm/{' Illal Hert:; ~MVI'S hovl! little 10 do witlt the r ('sulls obtailied 1!t.'CII at S11l0/l disto.,,/!.!. In Fig. 13 a transmitter is shown radia ting space waves of cO'lsiderabl e frequency. It is general1), believed that these wave~ fI~sS alon g the earth' s surface and thus affect tile receivers. I can hardly think of anything mo re improbable than this "gli ding wave" theor}' and the conception of the "guided wi.reless" which are contrary to all laws of action and reaction. \Vhy should these disturbances cling to a conduclor where thev are counteracted by induced currents, when they can propagate in all other directions unimpeded? The fact is that the radiations of the transmitter passing along the earth's surface are soon extinguished. Ihe height. of. the inactive zone indicated in the diagram. being some function of the wave length. the bulk of the waves traversing freely the a tmosphere. Terrest rial phenomena which I have noted conclusively show tha t there is no Hta v isidr layer., or if it exists, it is of no effect. It certain!)' would be unfortunate if the human race were thus l Ilirp/oue 11'e ore merely working /hrll a cotlde nur, the capacity of which is a fun ction o f 3 IO,R'ar1thmic ratio between the length of the conductor and the di stance from the ~rO\lnd. The receiver is affC(:led 1n t'xactly the !3me manner as from an ordinary transmitter, the only difference being tha t there ,s a cert ~i n modification of the- action which can be predetermined f rom the electrical constants. It is not at all difficult to maintain communication between an airplane and a station on the ground, on tht' contrary, the feat is vcry easy.' To mention another experiment in support o f my view. I rna)' refer to Fig. 16 in which twO grounded circuilS arc Showil excited by oscillations of the Hert~ian order. I! will be found that the antennas C;1Il be pm 0\11 o f paratlelism without noticeable change iii the action on the recei" er, thi s prO\'il1'~ that it is duc to cnrrents propagated thru . the grou nd and not to space waves. Partkularly si!Zllifieant arc the r esults obtained in cases illustrated ;11 Figure~ 17 and 18. In the fonn er an obstacle is shown in the path of the wave, but lmless the rc cciver is within thc effect ive t!ulroJllllir influence o f th e mountain range. tbt" SiglHlls arc 1I0t appreciably weakened by th e pre,· ence of the latter, becanse the currents pass I:nder it and excite thc circuit in Ihe same way as if it were attached to an energized wire. If. as in Fig. 18, a leeo nd ran J.!'e hap\>ens to be beyond the receiver. it could only strengthen the Hertz wave eliect by re flec· ti on, but a s a matter of fact it detrac ts ( C Oli/bUil d Oil pllge 87) May, 1919 ELECTRICAL EXPERIMENTER The True Wireless By Niko/a 1'<1$1(1 (Coutillu arakd fmmgrovnd ly spark gap Fig. 19. Comp"rlng t he Action. of T wo Form. of Transmitter a$ e earlng Out th e Fallacy of the Hertz·wave Theory. observed from day 10 day lhe effect is found to increase greatly with the dampness of the ground, and for the same reason T"ransmi/fu"..ilfl small terminal copoci!J ~ TO ALL RAD!O ~ AMATEURS ~ aOil We ha"e receh'ed many thOU!3.mh ~ of comlllunications from radio ama· i teurs for the past few m onths asking us about die status of their radio ~tu· lions, and whe n they will be allowed d to operate them again. = ~a lna~much as th cre has been uo omc:i:al information as to the reopening ._ of amateur , lations, durin g the :armi... tice, we can only say tlmt in alllikeli· § hood, amateurs wil! not be allowed to >--. = operate until act ual peaee h as been 5igned. In his executive order of §j I All ril the 6t1I, 1917, President W ilson '3 iii closed all r adio stations in the United State s b v an IIct al,prol'ed in tile Radio ~ Low of Augu~t 13, 1912. § !'"'l S Such 1= is onl)' a mea sure, accordi ng to for the duration of the law, war, § there bein g at presen t 110 legislation ~ §~ which prevenB anI' slation, am ate ur or ~ ~ o tlierwi5e, from ol,eraling after peace h os actua ll y bee n declared. Th e refore, ~ tbe minute neWS llapen announce tllat ~ Ii:! p.eaee bet..'een tile Un ited Stales and - iii ~ the Central P oweu has been signed. E ! j 6ft a",olellr s l<1li01lS /lulomatically r e- = vert 10 II, eir former slalus, and a lllil' ~ I "~' teurs need not wait for Jlermission to operate the ir &t9 tioI15, once peace has =5~1 heen declared. EDITOR.