CHAPTER VIII
RADIO GALORE
"A good many folks," said Bill, "get scared when they think about radioconstruction. The big words come at them all in a bunch like a lot ofbees, and it is to dodge. And when they go to the dictionary they arelost for sure. Potentiometer, variometer, variocoupler, radio frequency,amplification, loop aerials, audion and grids--no, I am not sayingthese words to show off. They are only a part of radio terminology. Andyou've got to get 'em, or you might as well take radio theory andconstruction on faith and be satisfied simply to listen in.
"Anybody can commit these words to memory without a dictionary, andthat's where my partner shines. He has heard the big words so much thathe talks them in his sleep, and he ought to know all their meanings, butthe one most his size is 'grid.'"
Here Gus drew a much scared boy, with hair on end and knees knockingtogether, surrounded by a lot of the words that Bill had pronounced.Then Bill, putting his hand to the side of his mouth and leaning towardhis audience as though in confidence, said in a stage whisper:
"He's doing that to show that he knows how to spell these words.
"To be serious about it, if I'm allowed," continued Bill, "this subjectof radio is a coiner in every way. Just think of someone sayingsomething in San Francisco and someone else in Maine listening to it,and without any speaking tubes, nor wires to carry the sound along! Agood many folks are wondering how it happens--how speech can be turnedinto electricity that goes shooting in all directions and how this isturned back into speech again.
"Well, it's done on the telephone, over wires. The voice in the receiveris turned into electric energy that passes over the wires and at theother end turns again into sounds exactly like the voice that startedit. But somebody found out that this same energy could be shot into theair in all directions and carried any distance, maybe as far as thestars, and then when pretty much the same principles were applied tothis as to the telephone, with some more apparatus to send and catch theenergy, why, then, that was wireless.
"It is really too bad, with all the useless short syllables in ourlanguage going to waste, that the fellows who got up the terms for radiowork couldn't have used words like 'grid,' for instance. They could havecalled a variocoupler a 'gol,' a potentiometer a 'dit,' an inductioncoil a 'lim,' (l-i-m) and a variable condenser would look just as prettyif it were written out as a 'sos'--but no! They forgot the good exampleset by the grid, the volt and the ohm and they went and usedjawbreakers.
"I'll tell you another thing that makes this electro-motive force asused in wireless easier to understand. It is the sun and its light. Agreat scientist, Doctor Steinmetz, says that light and electric wavesare the same thing. Perhaps they are, though they surely workdifferently under different conditions. But if the sun has an awful lotof heat it can't send it ninety-five million miles--not in reason! Theheat only makes light and that light travels through space. It reachesthe atmosphere of our earth and is converted into heat again. Perhapslight of the sun and stars and the reflected light of the planets do notshine through space as light, but as radio waves that either by ouratmosphere, or by our electrical conditions here are converted intolight again,--but this is hardly open to proof even."
Bill glanced at the blackboard; Gus had drawn a big sun, with radiatingrays, a grinning face, a small body with one short leg and two gesturinghands and had labeled it "Bill Brown, radio radiator." Bill made amotion of his thumb toward the caricature, then spread his hands in mockdespair, but not without a side glance expressing pride in hislieutenant's performance, all of which pleased the audience immensely.
Then Bill proceeded: "This electro-motive force which travels around andthrough our little earth is what we can actually experiment with. We donot know just what it is, but we are finding out pretty fast what itwill do. Perhaps there is hardly any limit to what it will do. It isgenerated for power and light and heat, for carrying signals and soundsover wires and through the air. What next? Just now we have got all thethinking we can do about radio. It is the sixth wonder that electricityhas sprung upon us. I guess we won't include electrocution.
"Now, there's no use going into technicalities about construction,that's a thing that must be studied out and thought over, not mussed upin a talk like this. I'll say this much, however, it is the vacuum oraudion tube detector that gives results, and the application of a loudspeaker is only possible with a vacuum or audion tube. It is as easy tobuild a vacuum tube set as a crystal set and only a very little moreexpensive. So, whether you are building or buying a set, make it a goodset, something that you can hear with a good many hundred miles.
"Now, you can buy the parts and build a receiving set that willgenerally give more satisfaction than a bought set." (Bill stepped overto the blackboard and took up a pointer.) "I may need this for thispartner of mine if he persists in caricaturing me instead of drawingwhat we want. We'll make things about four times as big as they ought tobe. You can use an aerial outdoors, which everybody now understands,or, just as well and a lot handier, a loop aerial indoors, the biggerthe better, but two feet in diameter is big enough.
"Here is your base and upright panel and this is the way to hook up orwire the parts. Here's your aerial and its ground, between which isplaced your variable condenser and tuning coil, thus, off here betweencondenser and coil comes the wire to your vacuum tube, with its fixedcondenser and grid leads, the wire being connected directly to the grid,while here the wire from the tube plate is connected with the six-voltstorage battery and in turn with the phones, like this. Then, from thephones to the ground wire, the wire is carried thus through a secondarydry cell battery, on each side of which the wires are taken off to arheostat, though my partner has sketched this to look more like a birdafter a caterpillar.
"I am not going to tell you how to make all these parts--if I did you'dprobably go to sleep, if you are not half way there already. So, if youcan't find out how to make the parts, or contrive them in some wayyourself, why, then, you'd better buy them. Only you can make the baseand do the wiring, attaching and so forth. Even my partner can do thatif he is watched pretty closely; it is almost as easy as making a sketchof it.
"If any of you really want to know how to build a radio set in apractical, get-there way, all you'll have to do is to get Doctor Field'sconsent and come round to our shop in the basement of the schooldormitory and we won't soak you much. I thank you all for yourattention."
Very warm applause indicated the approval of the audience, as Bill andGus left the platform. Again the president arose to say:
"Another of our students has a message for us in regard to radio. Amongthe notable pioneers and probably one to give the subject its greatestpractical impetus is William Marconi, whose name is familiar to you all.The great inventor is now an honored guest of this country, his yacht_Elettra_ lying off our shores. It seems doubly fitting that more thanspecial mention should be made of him, and as Mr. Antonio Sabaste was,in his native land, a neighbor of Marconi, his father being really afriend of the wizard, I think we shall listen with pleasure to what thisstudent of the school has to say."