SEPTIaLikk. 1922 Price 20c

VOL. 1

L

READING RADIO SYMBOLS

NUMBERV

COLOWAILSSPIGOT

5TOCIAGBAT TLii

Another Hook -Up for Two Variometers, a VariableCondenser and a Variocoupler

-111111111111""^"'

9iry Wenry Weer;vp

E -Z COMPANY, Inc. 614 ARCH STR RILTPHIL ADLLPHIA

WE WILL BUY IT FOR YOU.

It's enough to daze any beginner to walk into a radio storethese days. During the past year all sorts of companies havesprung up and the making of apparatus has flourished likea plague.

A lot of this apparatus is very fair stuff ; some of it isfine, standard high-grade material-and much of it is simplyjunk.

How is the beginner to know the good from the indifferentand the indifferent from the bacA?

The man behind the counter !will be free with his advice-but most of the men behind counters in radio stores nowa-days, calling themselves "Radio Engineers," aren't radio engi-neers nor steam shovel engineers. They'd do much better ascoffee -urn engineers in the places with the white trimmingsand the marble top tables. They pretend they know, but theysimply don't, and that's all there is to it.

If you are going to spend money on radio apparatus, andhave become interested in some particular make, ask Mr.Neely. He has given the products of most factories prettythorough tests and he will tell you just what value you canget for the amount of money you have to spend. He makesnothing out of it one way or the other. But, if he serves you,he is making friends for this magazine and that is his business.

If you prefer, tell him how much you can spare for a set.what you expect and he will buy the apparatus for you-allwithout any advance in price to you and no charge for theservice. He can get deliveries where you can't ; he knowswhat your money ought to buy and what kind of results youwill get with it. Let him do your shopping for you. Address.

HENRY M. NEELY,E -Z Experimental Station,

Delanco, N. J.

E -Z RADIOBY

HENRY M. NEELY

VOL. I. SEPTEMBER, 1922 NO. 5

Entered as second class matter May 26th, 1922 at the Post Offce,Philadelphia , Pennsylvania, under the act of March 3rd, 1879

Copyright 1922 by The E -Z Company, Inc.

CONTENTSThe Storage and B Batteries 3

How We Use Batteries 4

Storage Battery Needs Attention 6

A Loop Aerial Is Easy to Make 9

A Hook-up for a Loop Aerial 10

Some Ideas on Loop Aerials 11

Another Regenerative Hook-up 13

The Wave Length of Your Aerial 14

Protect Your Aerial Against Wind 16

Some Points on Crystal Detectors 17

Using a Variometer with the Crystal 19

A Costless Variable Condenser 21

Another Variable Condenser for You 22

Get Ready for Your Amplifier 24

Wiring Up Your Transformer 25

Getting Used to Radio Symbols 27

Some More Electrical Symbols 28

The Symbol for the Audion Bulb 30

The Symbols for a Modern Hook-up 32

The Symbols for a Two -Slide Tuner 34

A Glossary of Symbols 37

The Workings of a Condenser 38

Published monthly by the E -Z Company, Inc., 614 Arch Street, Phila.

Subscription Price Two Dollars The Year.

2 E -Z RADIO

SOME IDEAS ON LOOP AERIALS

Here are two suggestions for putting up efficient loop aerialswithout making them an eyesore to the Lady of the House

Here is a simple ho.k-up for the loop aerial and one that isespecially good for receiving on the longer wave lengths

E -Z RADIO 3

THE "STORAGE" AND THE "B" BATTERIES

VOLTS 3 AMPERESTo the left the picture illus-trates how we can multiplyamperage (quantity) withoutincreasing volts (pressure orforce). To the right we re-verse the process and increasevolts (pressure or force) with-out increasing amperes (quan-

tity).The stumbling block of most

amateurs who contemplate install-ing an audion bulb set is the highprice of the storage battery andthe trouble of keeping it constantlycharged and in good condition.

"Why can't we use dry cells?"they ask. "Dry cells will light theaudion bulb and make it work."

Well, dry cells can be used but,if there were not a very seriousobjection to them, storage bat-teries would not be so universallyrecommended.

"But electricity is electricity,"you may say.

That also is true, but there aredifferent kinds of electricity, justas there are different kinds ofbeans and potatoes and otherthings in this world. The storagebattery is built for one kind of

tkocrsI AMPERE

3 VOLTSAMPERE

472 VOLTS ..../71I AMPERE.

6 VOLTSI AMPERE. CELLAR

2 ND,

FLOOR

SI

FLOOR

service and the dry cell or the littlecell from the pocket flash lamp isbuilt for another kind.

There are two aspects of elec-trical current which we have toconsider in this problem. I am notgoing to become technical beyondthe knowledge of the averagenovice so it is only necessary tosay that these two aspects areknown as "volts" and "amperes."

Now roughly, the difference be-tween these two can very well beillustrated by our old friend, thetank of water in the attic and thepipe -line leading from the atticdown through the house.

If you have a spigot on the pipejust where it comes out from thetank, and you open this spigot, thewater will flow out but will nothave a great deal of force to it.

Go downstairs to the floor belowand open a spigot there and youwill find that the water will flowwith greater force than it did inthe attic. This is because you

4 E -Z RADIO

have an added drop of 8 to 10 feetfrom the tank and the force ofgravity always adds force to afalling body the farther that bodyfalls.

Go down two floors below; theattic and open a spigot there andyou will find that the water willspurt out with decidedly more forcethan it did from the tank.

Go all the way down into thecellar, open a spigot there and youwill find that the water will haveforce enough to run a small motoror water -wheel.

This is due to what we call the"head" of the water-in otherwords the height from which itfalls. A head of 50 feet will havea great deal more force than ahead of 25 feet, and a head of 1 or2 feet will have very little powerbehind it.

This head of water is similar tovoltage in electricity. Voltage isthe power behind the current. Wemeasure it in terms of 1 volt or 6

HOW WE USE STORAGIn the last article we said that

volts in electricity might belikened to the "head" of water ina pipe from a tank-in other words,the distance it falls, which governsthe pressure behind it. So voltsmeans pressure of electric force.

Amperage, we said, was like thesize of the pipe in the water sys-tem, and is, for practical purposesof explanation, a measure of theouantity without reference to theforce behind it.

The ordinary dry cell, of whichyou will find eight in the pictureaccompanying this article, has apressure or force of one and a halfvolts between the positive bindingpost and the negative binding post.

volts or 100 or 1000 volts, as thecase may be just as we measurethe head of water in feet.

The other aspect of electricity,amperage, might be likened to thesize of the stream which flowsfrom the tank. If you have a1/2 -inch pipe leading down throughthe house and open the spigot inthe cellar, the water will flow withthe regular speed of water at thatheight, but you will not get somuch of it in a given time as ifyou used a pipe 2 inches in diame-ter. The diameter of the pipegoverns the quantity of water andthe head governs the force atwhich it flows, or the pressure be-hind it.

While the comparison is notstrictly accurate, it is sufficient forour purpose to know that amper-age is to electricity very muchwhat the diameter of the pipe is towater-that is, more or lessroughly, an indication of the quan-tity.

E AND "B" BATTERIESTo use our water -supply illustra-tion, the positive post might becalled the tank in the attic and thenegative post might be called thespigot from which the water isdrawn, and the voltage is like the"head" of the water.

As we have the four dry cellsconnected in the upper picture-we call this connected in "series"-it might be likened to the watersystem through the various floorsof the house. The first cell givesone and a half volts (force) ; thesecond cell, which might be calledthe floor below, gives another oneand a half volts, making threevolts at this point. The third celladds a further force of one and a

E -Z RADIO 5

STORAGE. BATTERY

Above is a typical storagebattery for lighting audionbulbs. To the right, in theupper illustration, are fourdry cells connected in "se-ries." Below them are fourcells connected in "paralleL"Below that to the left is thekind of dry cell used in smallpacket flash lamps, and to theright is a typical little "B"battery, made up of a numberof these embedded in an in-

sulating substance.

half volts, making a total force offour and a half volts. And the lastcell is the spigot in the cellar, andwhen we open this we get the fulleffect of the drop, which, in elec-trical terms, is six volts.

Each of these cells has a certainamperage. In the ordinary dry cellof this type there are thirty am-peres. Connected as the cells arein the upper illustration, the am-perage is not affected, but the volt-age is added, just as it would be ina water system if the pipe goingfrom the attic through the differ-ent floors to the cellar were all oneand a half inches in diameter. Thestream which came out of thespigot in the cellar would have thefull head of the tank, but wouldstill be only one and a half inchesin diameter. .;

V LAS H LIGHT B BATTERYCELL

Thus connecting electrical bat-teries in "series" adds the voltage,but does not affect the amperes.

The four cells just below theupper one are connected in whatwe call "parallel" or "multiple";that is, all the positive bindingposts are connected to each otherand all the negative binding postsare connected with each other.

We can illustrate the effect ofthis by again considering ourwater system and rememberingthat in the upper illustration weused each cell to represent onestory of the house. Joining themin series gives you the force of allfour stories. Joining them inparallel means that we go only onefloor below the tank, but, instead oftaking all the water through onepipe, we use four pipes and openthem all at once. This means that,while the force of water as itleaves the spigots is not very greatbecause it has flowed only onestory, we are getting four times asmuch water because we are usingfour pipes.

6 E -Z RADIO

Thus connecting electric batter-ies in parallel adds the amperageor quantity, but leaves the voltage,or force, the same.

The great difference between astorage battery and a dry cell isthat, in the storage battery, theelectricity is made by a combiningo f various chemical elementswhich are in the solution, and theadvantage is that when these ele-ments are all combined and there isno more electricity to be made, wecan introduce a charge of elec-tricity from an oufside source intothe solution, and this breaks theelements up again into their origi-nal form until, when the battery isfully charged, all the elements areprepared, when called upon, tostart combining all over again, andthus make more electricity.

The usual storage battery has aforce or power of six volts, and thedifferent sizes are rated in "am-pere-hours"-that is, the numberof hours for which the battery willdeliver a steady current with the

YOUR STORAGE BATTE

Once you have your "B" batteryinstalled in your set and properlyhooked up you will not have tobother much about it so long asthe electricity that it gives seemsto have plenty of "kick" to it.

When the electricity ceases to bestrong enough there is only onething to do-throw the batteryaway and buy a new one.

Fortunately, though the plate ofyour audion bulb requires a power-ful current, it uses very little of itand a good "B" battery ought tolast you for six months or more.

The storage battery, however, isa very different proposition. Here

quantity of one ampere.Dry cells, which are of about

thirty -ampere capacity, will reallynot deliver an ampere for thirtyhours on a steady flow. They arebuilt for frequent periods of shortservice and, once they are dis-charged, they cannot be recharged.

So we use a storage battery forthe steady lighting of our audionbulb.

The "B" battery is simply a col-lection of small dry cells usuallyall mounted into a block of someinsulating material. They areconnected to the part of the audionbulb known as the plate, and theoperation of the plate, while re-quiring a high voltage requiresvery little amperage-in fact, onlyabout one -fiftieth of an ampere.

In our water illustration it mightalmost be likened to a tank placedat the top of the Eiffel Tower, butconnected to the ground by a pipeonly the size of the tube of a ther-mometer.

RY NEEDS ATTENTION

we have a piece of chemical mech-anism which is called upon to de-liver quite a strong current, to givea good deal of it, and to give itsteadily in a long service.

The dry cell is not fitted for thisstrenuous work and, while four drycells hooked together will give youfairly satisfactory service in light-ing your filament for a short time,they very soon reach a point wherethe service becomes most undepen-dable. Though there may be a gooddeal of life left in them, it is notthe kind of life that will do for thispurpose.

Four dry cells at forty cents

E -Z RADIO 7

With the apparatus shown inthis picture a storage battery can be kept in good con-dition for a number of years.To the left is one of the manytypes of "rectifiers," by meansof which you can charge yourbattery by plugging into anelectric light socket; next isthe storage battery hooked tothe charger, next to that isthe hydro -meter s y r i n g e,which will tell you the con-dition of your battery at anytime, and next to that a bottleof distilled water whichshould be added to the solu-tion about once a week to keepthe plates of the battery im-

mersed.

apiece make $1.60, and I doubt ifthey would last more than a weekwith any efficiency left at the endof that time. It would not takemany weeks at this rate to coverthe cost of a first-class storage bat-tery.

With the storage battery youwill have three very great advan-tages. First, the current you willdraw from it will be steady andjust the kind of a current you wantfor radio purposes ; second, it willstand up efficiently many times aslong as the dry cell; third, whenthe charge is exlusted it is aninexpensive matter to have a newcharge put into it or put one 'inyourself by hooking it up with yourhouse lighting current with the

proper apparatus in between and itit is ready to begin all over again.

A storage battery requires look-ing after just as does any otherdelicate and efficient piece ofmechanism.

First, there are certain thingsyou must be careful of in order tocover the requirements of the fireunderwriters. They have decreedthat the battery must be com-pletely housed so that all liveparts are covered. They also de-mand that you connect the bat-tery to your wires through fuseswhich will not allow more thanten amperes to pass. This is doneso that if two wires come acci-dentally in contact the fuse willblow out and the current will bestopped before it has a chance tostart a fire. They also have ruledthat storage batteries which haveexposed terminals must be pro-vided with a ventilated cover ofsuch a nature that it will preventaccidental short circuit across theterminals. They insist that thewiring between the storage batteryand your radio apparatus be not

8 E -Z RADIO

less than No. 14 B & S gauge ap-proved rubber covered.

The underwriters say nothingabout your eyes and your clothes,but let me warn you not to spill theacid of the battery upon the carpetnor let any part of the battery,which is moist with this acid,touch your clothes. I once had aman carry a storage battery ashort distance for me withoutwarning him of it and about anhour afterwards the cloth of histrouser legs, against which it hadrubbed, simply fell to pieces.

And above all, after handlingany part of the battery, do nottouch your eyes. I do not knowthat this acid would cause blind-ness, but I do know that it cancause most uncomfortable pain.

Never have a flame near the topof a freshly charged battery.During the process of charging andfor some time afterward the solu-tion forms a gas which is highlyexplosive.

Examine your battery throughthe filler -caps at least once a weekand see that the solution is wellabove the edges of the plates. Ifit is not, pour in distilled water ora chemically pure water that youcan get from the drug store, untilthe plates are well covered. If thesolution becomes weak it is muchbetter to let a man in charge of theregular battery station do the re-filling for you rather than attemptit yourself.

There are many makes of"home chargers" on the marketnow, all designed to change thealternating current of your houselighting system into a direct cur-rent not too strong for the batteryand, with one of these, you simplyplug into a light socket and the

battery will charge overnight atthe expenes of only a few cents forcurrent. These charging devicesmay seem expensive, but they arewell worth while because a batterywhich is "boosted" a couple oftimes a week will give two or threetimes the length of service of onewhich is used to the limit and thenfully recharged.

For a dollar you can get what isknown as a "hydrometer syringe,"which will give you an unfailingindication of whether your batteryneeds charging or not.

Inside the glass part of the sy-ringe is a little glass thing thatlooks like a thermometer tube.When you squeeze the bulb of thesyringe and take some of the solu-tion into the glass barrel, this littletube floats and the point on thescale at which it meets the surfaceof the solution tells you what the"specific gravity" of the solution is.

A fully charged battery will in-dicate around 1280 on the scale,while a fully discharged one willread about 1125. In actual serviceyou should never let the specificgravity of this solution get below1200.

Storage batteries are graded ac-cording to their "ampere -hour" ca-pacity-that is, the number ofhours for which they will steadilydeliver a current of one ampere.It is best not to get a battery ofless than sixty ampere hours forradio purposes. The average au-dion bulb will use about one amperean hour, so that your battery wouldburn for sixty hours continually.If you are using two amplifiers aswell as the detector you will beusing three amperes an hour andyour battery will last twentyhours.

E -Z RADIO 9

BINDING

A LOOP AERIAL IS EASY TO MAKE

yCE11-1443

)

WIRESTel SET

Two forms of frame work for loop aerials. On the left is asimple square of boards notched at the corners to hold thewires in place. On the right is a more elaborate and workman-

like frameA loop aerial is so easy to make

that it is worth any one's whiletrying during the static seasonjust to see what results he gets.

So-called experts in radio willwrite long and learned disserta,tions saying that certain thingscannot be done, and these disserta-tions meet with loud laughter fromhundreds of school boys all overthe country who are actually doingthese things.

As a matter of fact, radio is sucha new and comparatively little-known miracle that no man oughtto say positively that a thing can-not be done. I have seen dozens ofarticles printed under the names ofvarious leaders in this science, allstating definitely that it is uselessto try to use a loop aerial with acrystal detector. I made the same

statement myself in these articlessome time ago, and shortly after-ward an amateur of my acquaint-ance, just to see whether I wasright or not, hooked a loop aerial tohis crystal and quite clearly heardthe concert from Schenectady,more than 200 miles away.

This is a freak, of course, but ithas always been the freak happen-ings in radio that have led to dis-coveries which later made themthe ordinary happenings.

I still do not advocate trying aloop aerial with a crystal receiverin spite of my friend's one triumph.But if you have an s.ndion bulb setit is decidedly worth trying.you have any success with it at allyou will find it of inestimablevalue in cutting out interferencefrom other stations and it will also

10 E -Z RADIO

eliminate a great deal of static.Very few amateurs will want to

use loops that are more than threefeet on a side, so that is the size Ihave given in the illustration. If,however, the lady who bosses youaround at home does not object toits appearance, there is no doubtthat a four foot loop is more satis-factory.

The simplest-though most un-sightly-form of loop aerial isshown in the left-hand picture. Itis merely four boards nailed to-gether firmly at the corners andsuspended from a hook in the ceil-ing. The corners of. the frameshould be notched to receive thewires and insulated wire should beused. A strip of wood should benailed to the lower corner to re-ceive the binding posts and the twoends of the wire should be attachedto them.

In using this aerial, it should behung 4 few feet away from theoperator and a string should be runfrom each of the two horizontalcorners to the operating table.You then turn the loop around byhandling these strings much as youwould handle the reins in driving ahorse, and when you have the looppointed in the direction from whichyou hear the loudest signals youtwist the strings around a nail or

A HOOK-UP FOR T

One of the most interestinghook-ups for an indoor loop that Ihave tried is given at the bottomof page 2 in this issue. The mainpoint of difference between thisand the one given last month is inthe fact that there is a wire con-necting the positive post of thestorage battery to the center wireof the loop. This connection is in -

a screw on your table and thatholds the loop in place.

The frame work on the rightmakes a much neater -looking joband avoids the necessity of hang-ing the frame from the ceiling.Such a loop can be stood on thetable or the floor and can be turnedabout either by the strings justmentioned or by a long stick.

Almost any kind of wire will dofor these loops, but it is usuallybest to use an insulated wire.Otherwise there may be dampnessin the wood which will permit someof the weak currents to leak acrossfrom one turn to another.

Ordinary bell wire is excellentfor this purpose or you can usewire as small as number 22 doublecotton covered. Theoretically it isbest to use a wire consisting of anumber of strands twisted to-gether, but this is expensive and Idoubt that the advantage is worththe extra money.

It seems impossible to make theaverage novice give up the impres-sion that he should have his win-dows open in order to receive sig-nals on a loop or an indoor aerial.This is not necessary at all. Youcan shut your room up tight andstuff every crack and crevice withsealing wax, and the radio waveswill come merrily in just the same.

HE LOOP AERIAL

dicated at the point marked A inthe drawing.

Oddly enough, though I havenever seen the peculiarity men-tioned in any text books, I foundduring two weeks' experimentingwith this set that hooking the bat-tery to the center wire seemed en-tirely to take away the loop's "di-rectional properties." I could turn

E -Z RADIO 11

my loop in any direction or lay itflat on the floor or raise it hori-zontally above my head, and themusic came in just as well.

I have often been curious toknow whether other experimentershad the same result, but havenever been fortunate enough tomeet one who has tried this hook-up, so that I am still uncertain asto whether my experience was theresult of a freak combination ofconditions or whether this hook-up does in reality take away thedirectional properties from theloop. I should be very much in-terested to learn any results thatyou obtain from it.

This hook-up is intended par-ticularly for stations sending onlonger wave lengths than thoseused in broadcasting. The variablecondenser, wired up as indicated,increases the wave lengths of theloop, and the connection with thestorage battery on the positiveside makes the hook-up especiallygood for what are known as C. W.signals, which, of course, include

the concerts.

In the recent article on the con-struction of loop aerials I spoke ofthe advantages for certain kinds ofwork of making a loop with quitea number of turns and arrangingit so that the wires from the bind-ing post can be hooked on to anyturns desired by means of clips.

This arrangement is especially use-ful for this hook-up.

This arrangement of instru-ments has for the novice some ad-vantages over the one given in thearticle last month. In the firstplace, it uses less instruments, andis, therefore, cheaper, and as it hasless variable parts there are not somany adjustments to make.

But do not forget that it is al-most an axiom in radio work thatsimplicity of operation is alwaysgained at the expense of selectivetuning-that is, the fewer partsyou have to adjust the less you areable to tune out annoying interfer-ence.

For this reason I have foundthis hook-up to be rather unsatis-factory in a city where there arefour or five broadcasting stations,whereas with the hook-up given inthe preceding article I have beenable to tune out all interferencewith almost uncanny facility.

Still, I would be almost inclinedto say that the novice who hasnever used a loop had better trythis one first merely for thegreater ease with which stationsare picked up by it, and then afterhe becomes proficient in its usehe can graduate to the more dif-ficult and more expensive but un-doubtedly more selective arrange-ments given in the other article.

SOME IDEAS ON LOOP AERIALS

The present winter will undoubt-edly see most radio enthusiastsconcentrating on some form of loopaerial in connection with the newArmstrong super regenerative cir-cuit. Just as soon as we can getthis circuit worked down to thepoint where the beginner can use

it, it, with a neat little loop aerial,will solve the difficulty that con-fronts the city dweller who finds itimpossible to erect an outdoor an-tenna.

Most amateurs seem to under-stand the principles of the loopaerial, but nine out of ten, judging

12 E -Z RADIO

from my letters, are puzzled as tothe best way to mount the frameso that it can easily be turned inthe direction of the station thatyou want to receive.

I will admit that the forms ofloop aerial given in almost all pub-lications do present difficulties ofconstruction to discourage a manwho is not an expert with tools. Ihave myself found it hard at timesto mount a frame as solidly as Iwanted it without damaging thefurniture or making a contrivanceso big and ungainly as to bringforth the disapproval of The LadyWho Bosses Things Around theHouse.

I want to give here a few hintsthat will solve your difficulty with-out sacrificing any efficiency. Youwill find them illustrated on page2 of this issue.

The first plan is to take an ordi-nary mosquito screen frame whichyou would put on the outside of awindow in the summer time andmount it on the inside of the win-dow frame by means of two hingeson one side of it. The loop canthen be wound around this screenframe and can be made of ordinarybell wire fastened at each cornerby a brad or a tack. You mustremember that the insulation onthis wire will not prevent the re-ception of radio signals, but is verydesirable in preventing the leakageof electrical currents from wire towire.

For the average size of window

screen frame, about six or seventurns of wire will be sufficient, butit should have a variable con-denser in the circuit connected bythe "series -parallel switch" whichI have already described in thesearticles.

A screen swinging on hinges inthis way can be turned through anarc of half a circle and, as you willget reception from a station towardwhich either one of the two sidesis pointed, you will get your sig-nals from a complete circle.

In this same way a loop can bewound around a door, only in thiscase you will require only aboutfour turns of the wire. Openingand closing the door will allow youto swing your loop through a suf-ficient arc to find the station thatyou are looking for.

I have also seen loops wound onone panel of a Japanese screen anda friend of mine has one woundupon a fire screen in such a waythat it is almost invisible.

In any case connect a variablecondenser by means of the series -

parallel switch already spoken ofand this will compensate for anyerror in the number of turns ofwire that you make.

You can make a close enoughestimate of the correct number ofturns when you know that forbroadcast concerts a loop four feeton each side should contain fourturns of wire spaced one-half inchapart.

E -Z RADIO 13

UN I T-5

ANOTHER REGENERATIVE HOOK-UPAERiAL

TENS

xeCOLOWATERSPIGOT

ow.

vAGNOMITILR

VARIABLEc oNDGNGER

B BATTER..

t'.1JES

(Su I

Mmialow+dGRID CONCH NsellAAE.LW

RHEOSTAT

TOL/AGEBA, TEL,

Another hook-up for two variometers, a variable condenserand a vario-coupler

To nine persons out of ten whoget well into this radio craze andbecome what we ordinarily knowas "bugs," the mere listening tothe broadcasting concerts has verylittle thrill and the great joy ofradio arrives with a tableful] ofmiscellaneous apparatus, most of itprobably home-made and not at allexpensive, and a scrapbook madeup of a great collection of diagramsof hook-ups gathered from dozensof different sources.

Operating the radio set then be-comes a real joy.

Not long ago a friend of minecame to my experimental stationfour or five times in one month inorder to listen to a radio concert,and each time he found me in themidst of unhooking my set pre-paratory to trying some new ar-rangement that I had come across.

There is no one hook-up that isbest for every purpose and aerialand every location. Whenever youget a set that is designed to receiveeverything that is flying throughthe ether, you will know that youhave a set which has had to sacri-

fice a certain amount of efficiencysomewhere in order to be generallypracticable.

These different hook-ups are not,of course, of particular interest tothe man who simply wants to hearthe broadcast concerts, but, a3most of you, will inevitably laterdevelop into real bugs, it is just aswell at.the very beginning to startmaking a scrapbook of all the hook-ups you find and when your operat-ing room has become cluttered upwith so much junk that it looks likethe sales room of a dealer in sec-ond-hand apparatus, you will enterinto the real heaven of the radiofan and get the full joy of thiswonderful new science.

One of my most prized posses-sions is a big bundle of notepapermade up of the data that I havejotted down night after night whiletrying these different hook-ups. Igive each hook-up in my scrapbooka number and when I sit down atmy table to test it out, I place thisnumber on the top of each sheet ofthe notepaper which is on my table,then I rule off columns and lines

14 E -Z RADIO

and tune in some station. As soonas I get it strongest I make a notein a column headed "audibility" ofthe strength with which it comesin.

This audibility scale, which Irange from 0 to 10, cannot beexact, but it is near enough to bevery interesting. Under the 0classification, I place the stationwhose call letters I can just barelymake out with the aid of my im-

agination and enough sound in thetelephones to enable me to identifyit after I have heard it a numoerof times.

Under the 10 classification Iplace the signals which come in sostrong that they actually make thetelephones rattle unpleasantly inthe ears. No. 5 is the signalwhich comes in with fairly goodsatisfaction. Other intensities ofsound are graded in between ac-cording to my judgment.

Under other column headings onthe record I enter the dial settingsof the various parts as they werewhen I got best results.

Naturally the usefulness of sucha system is very largely increasedwhen you acquire sufficient ac-quaintance with the dot and dashcode to enable you to identify themany amateurs and commercialstations which are constantlyworking with each other throughthe ether. And let me say right

THE WAVE LENGTHEvery amateur, as he continues

the study of radio, becomes curi-ous to know what the "naturalwave length" of his aerial is.

There are many formulae fordetermining this, but those thatgive really accurate results requiremeasurements and calculationswhich are beyond the scope of thenovice.

here that it is worth all the troubleit requires to learn this code, be-cause then you can get into thelong distance work and experiencethe genuine thrill that comes toyou when you first hear a stationin Europe or South America.

This hook-up which we give to-day is not, however, suitable forthe reception of stations workingon the long commercial wavelengths. It is designed especiallyfor amateur and concert broad-casfing waves.

It uses the same instrumentswhich were given in our othertwo-variometer hook-up, but itplaces the variable condenser in adifferent position and many ama-teurs will find it more satisfactorythan the other. I have been usingit myself for some time with verygood results.

The opuating directions givenfor the other set apply to this onealso. After all, such directionsmerely narrow themselves down toa matter of patiently twisting yourknobs until you find what you areafter.

But let me again give the cau-tion which is applicable to all hook-ups using an audion bulb. That is,don't put too much storage batterycurrent into your bulb through therheostat. Always operate the bulbwith the filament at minimum bril-liancy for strong signals.OF YOUR AERIAL

It is, however, possible to makea rough estimate of the averageaerial and equations for doing thiscan be found in most books onradio.

These equations use various fac-tors, the principle of which are thelength of the aerial, which meansthe number of feet from one insu-lator to the other regardless of the

E -Z RADIO 15

number of wires, the height of theaerial, which means its averageheight above the earth, the lengthof the lead-in, which means thenumber of feet from the placewhere the lead-in wire joins theaerial to where it joins the instru-ment and the length of the groundwire, which means the number offeet from the ground binding poston the set all the way to the earth.even though the greater part ofthis may be your cold -water pipe.In such a case the cold -water pipeis merely a part of the "groundwire" and the "ground" itself iswhere the pipe goes into the earth.

It would only confuse you if Iwere to give a number of formulaefor calculating your wave length,because you would find differentresults from each equation. I willonly give the approximate naturalwave length of the commonest kindof aerials and you can make a fairlyclose estimate of yours from them.

For a four -wire aerial whichtakes its lead-in from one end theapproximate wave lengths are:

Fifty feet long - Thirty feethigh, 98 meters ; 40 feet high, 110meters; 50 feet high, 125 meters;60 feet high, 140 meters.

Sixty feet long - Thirty feethigh, 105 meters ; 40 feet high, 115meters; 50 feet high, 135 meters;60 feet high, 150 meters.

Seventy feet long-Thirty feethigh, 120 meters ; 40 feet high, 130meters; 50 feet high, 145 meters;60 feet high, 155 meters.

Eighty feet long-Thirty feethigh, 135 meters; 40 feet high, 150meters; 50 feet high, 160 meters;

feet high, 175 meters.Ninety feet long-Thirty feet

high, 145 meters; 40 feet high, 155meters; 50 feet high, 165 meters;CO feet high, 180 meters.

One hundred feet long-Thirtyfeet high, 155 meters; 40 feet high,165 meters; 50 feet high, 180meters ; 60 feet high, 200 meters.

One hundred and ten feet long-Thirty feet high, 175 meters ; 40feet high, 185 meters ; 50 feet high,200 meters; 60 feet high, 215meters.

If you have only a single wire,pick out your height and lengthfrom this and reduce the abovewave length by about 15 or 20 percent.

If you take your lead-in fromthe middle, reduce above wavelengths by about 50 per cent.

One of the formulae which ismost in use is the following:

Add the length to the lead-in,add to this the ground, and if thereis more than one wire in theaerial add one-third of the over-alllength of the aerial. This is all infeet. Divide this total by two andadd the result to the first total.This is said to give the naturalwave length in meters.

It is probable that the naturalwave length of your aerial will besomewhere about midway betweenthe results given by this formulaand the table I have given.

16 E -Z RADIO

PROTECT YOUR AERIAL AGAINST WINDTeo . ;*-!.

hzsalatorAerial Wre

This shows the best methodof attaching an aerial to atree to insure against break-

ing the wire in a wind storm

p

It is probable that eight out often amateurs, in erecting theiraerials, make use of at least onetree in place of a mast and it isequally probable that not one ofthe aerials so erected fails to breakduring some heavy gust of windwhich strikes its locality.

Many amateurs attach an end ofthe aerial to a part of the treetrunk that looks perfectly strongand stiff and they find it impos-sible to realize what has happenedwhen they go out some morningand see their wires trailing patheti-cally on the ground.

But the "windage" in a tree isconsiderably greater than youwould suppose. A mere twenty -mile wind getting among the lux-uriant branches of a healthy treein summer time, will exert a pres-sure of a great many hundredpounds and in most cases will startthe tree swaying or oscillating sothat it gathers added force eachtime that it swings outward. Itdoes not take long for this swing -

1,e".

'ClothesZ/I7e

//ear/yRock.

ing force, snapping the wiresquickly verytight, to break the strands andanother radio set is out of com-mission.

Whenever a tree is used for thesupport of an aerial this should beprovided against and it can be doneby a very simple method.

The sketch shows the easiestand probably the most efficientway. You simply take a pulley ashigh up in the tree as you can getit and lash it fast around a limb.Then you pass a clothes linethrough the pulley, tie one end of itto your aerial insulator and let theother end drop to the ground.

Meanwhile you must get a largerock or a heavy iron weight or ahalf dozen bricks and these will beyour assurance against a breakingaerial.

Pull your clothes line until youraerial is perfectly tight and thentie the heavy weight on the endof the line just high enough to

E -Z RADIO 17

allow the weight to swing a foot ortwo above the ground when theaerial is taut.

Ten or fifteen pounds will dofor the weight for the ordinarysingle wire aerial, but if you havemore than one wire with spreadersyou must put on more weight.This is a matter that can be de-

cided only by experiment, theobject being to have the weightheavy enough to keep the aerialwire perfectly taut.

It does not matter upon which

end of the wire you put this pro-tection. The object is simply togive your aerial a certain amountof elasticity, and this elasticitymay be put either at the near orfar end.

With this arrangement, whenthe tree sways away in the wind,the clothes line simply slidesthrough the pulley, lifting theweight slightly higher. When thetree sways back again, the clothesline slides once more, letting theweight drop and the aerial stays ata uniform tension all the time.

SOME POINTS ON CRYSTAL DETECTORS

Here are the best types ofstands for using a crystal de-tector. There are many dif-ferent makers specializing inthese types and their advan-tages are described in the ac-

companying article.

It is a perfectly easy thing tosit down and write an article tell-ing how to make a complete receiv-ing set for a dollar. I have beenmuch amused at a number of sucharticles I have seen and particular-ly at the ingenious devices evolvedto take the place of the usual crys-tal detector stand. Most of thesedevices simply use a twisted wireto make the contact with the crys-tal and you are directed to find thesensitive spot with it.

Instead of telling you to find thesensitive spot they ought to dare

you to find it. These things are allright for the experienced amateurwho knows exactly where and howto locate trouble in his set, butthere is nothing that gives theaverage beginner more bother thanfinding-and keeping-a sensitivespot on his piece of mineral.

It is astonishing the number ofdifferent types of crystal holdersthat have appeared on the marketsince this radio broadcasting crazebegan. I think I must have per-sonally tested fifty of them andthese tests have convinced me that

18 E -Z RADIO

the only type for one who is hot skilled in radio is some such ap-paratus as shown in the illustra-tion. There are many makes onthe market using this general prin-ciple and the choice may well beleft to the one which the purchaserfeels fits his hand the best.

This style of stand holds thecrystal in a cup or clamp on thebase, attached to one binding post.The cat -whisker wire id bent atright angles and is mounted upon aball and socket joint or a pair ofswivels or gimbals or some sucharrangement to give it absolutelyfree play in all directions.

The advantage this type ofstand has over all others is due tothe fact that a difference of pres-sure almost of the weight of afeather applied to the catwhiskeron the detector will cause a vastlygreat difference in the clearnessand strength of the signals. Forthis reason, all devices which havea spring pressure are bad and thosewhich depend upon a screw andthread are undesirable because, themoment you go to screw in or out,you are almost certain to take theend of the catwhisker off the sen-sitive spot and you may have aheap of trouble finding it again.

And this leads me to anotherpoint about galena which does notseem to be generally understood bybeginners. This is the fact that,while a piece of galena may be avery fine detector, it may have allof this ability stored in one par-ticular spot no bigger than a pin'shead and be absolutely dead allover the rest of its surface. Onceyou get your catwhisker awayfrom this tiny efficient spot youmay have your own troubles find-ing it again.

I have had a number of pieces ofgalena which had this peculiarityand I have found that in nine casesout of ten, scraping the surfacequite deeply with a knife bladewould uncover many more sensitivespots and even breaking up thecrystal into three or four pieceswith a hammer gave me three orfour excellent detectors in the placeof one, even though these detec- tors were smaller.

If you do this you may be puz-zled as to how to mount thesesmall pieces in the detector stand.This is quite easy. Simply embedthem in a ball of tinfoil from a packof cigarettes or a piece of choco-late and clamp the tinfoil in thedetector stand.

I once got excellent results froman experiment I tried with four orfive pieces of galena upon which Icould not find a single sensitivespot. One of these pieces wasmounted in composition in theusual cup so I simply melted thecomposition away with my solder-ing blow -torch, replaced the emptycup on the stand, ground up all ofthe supposedly dead crystals into afairly fine powder and filled the cupwith it. Thereafter I found plentyof sensitive spots and, if there wasany difficulty in finding one, I tap-ped the cup fairly hard with myfinger -nail and this usually lo-cated what I wanted.

And this search for a sensitivespot leads me to one other phase ofthe crystal detector which does notamuse me but fairly makes mefurious. This is the failure of be-ginners to use buzzer testers. Itreminds me of my first assignmentas a ship's operator. I sailed on amolasses tanker for Cuba on anhour's notice and found that theold-fashioned set with which I was

E -Z RADIO 19

to be ship -mates had no buzzertester. Two days north of Miami,Fla., the "old man" filed a messagefor that station and I called themon a powerful two -kilowatt set andlistened for an answer, but therewas none. It was my first com-mercial message and I was deter-mined to get it through so I sat upall night calling Miami every fif-teen minutes without success. Indesperation I spent all of my timein the wireless shack hurling"WST's" through the ether with noresult.

Late the next afternoon I heardthem answer me and tell me to goahead. I shot my message, got myreceipt and rushed up to the "oldman."

"I got it through," I said trium-phantly.

He sneered and pointed silentlyto the Florida shore not five mileswest of us. There were the greattowers of the Miami station whichhad been heard regularly all theway across the Atlantic Ocean andI was proud of having heard themfive miles ! I learned later thatthey had heard my very first call.and had acknowledged it; but hav-ing no buzzer tester to tell me thatmy point was not on a sensitive

spot of the detector, I could nothear them and I wasted two wholedays and must have interferedwith dozens of important messagesby my wild calling every fifteenminutes.

By all means put a buzzer testeron your crystal set or, if you don't,don't blame the apparatus.

USING A VARIOMETER WITH THE CRYSTAL

There is nothing in my corre-spondence which surprises memore than the number of personswho have bought variometers fortuning devices with a crystal detec-tor. This is a very inefficient wayof tuning a crystal set and cannotcompare with even the most care-lessly made home -built tuning coil,but so long as a great many peo-ple seem to have loaded themselvesup with variometers I will give ahook-up to enable them to use thisinstrument and get what satisfac-tion they can from it.

We all know that the aerial it-self has a certain natural wavelength. This wave length dependsupon the height, length, the num-ber of wires and certain local con-ditions.

If the natural wave length ofyour aerial should happen to be 100meters, and you add to it a tuningdevice whose range of wave lengthsis from fifty to seventy-five meters,you know that the wave lengthrange of aerial and tuning devicetogether is only from 150 to 175meters.

20 E -Z RADIO

-...1105111111111111:1111110. A. E_R A L

vARIONIETER

COLD WATERSPIGOT

CRYSTAL DETECTOR

OmotqLCONDENSER

PHONES

This is the best hook-up for using a variometer with a crystal detector

It is because the average ama-teur aerial has rather a small wavelength that we have to provide re-ceiving sets containing tuning de-vices which have a comparativelywide range of wave length possi-bilities in order that they may/hesatisfactorily hooked up to allied/hi'any aerial.

. The wave length range of avariometer is quite small, and itwill not give you satisfaction unlessyou happen to have the right wavelength of aerial to add to it.

The illustration shows the ac-cepted method of hooking up avariometer to your crystal detec-tor. It does not, however, give the

buzzer tester, but I have so fre-quently insisted upon the necessityof this that I hope that none of myreaders would think of installingany kind of crystal set withoutadding to it the buzzer tester,which has already been so fullydescribed in these articles.

When you have hooked up yourvariometer as shown in the illus-tration and find that you do not getsignals, no matter which way youturn your knob, the chances arethat your wave length is too short.If you have a variable condenser,you can increase the wave lengthby hooking up the two bindingposts of the condenser to the twobinding posts on the variometer.

I

E -Z RADIO 21

This will give you a much moreelastic method of tuning, as youcan vary wave length both bymeans of the condenser and thevariometer.

. If you have no variable con-denser, a grid condenser or a phonecondenser hooked up in the sameway to the two terminals of your

variometer will increase your wavelengths and may give you the sig-nals you are looking for or else youcan put a "loading coil" in the cir-cuit, hooking it between the aerialand the variometer. This loadingcoil can be a homemade spiderwebor one layer of wire wound tightlyaround a salt box or oatmeal boxand tapped about every ten turns.

A COSTLESS VARIABLE CONDENSER

Here is an efficient home-made variable condenser which re-quires only an envelope, a piece of cardboard, some Ln foil and

two paper clips

In another effort to combat thehigh cost of radio I want to de-scribe here one of the neatest andmost efficient home-made variablecondensers that the novice canconstruct.

This condenser, built as shownin the picture, will be of about thesame capacity as a fifteen -plate

variable, but its dimensions can bevery easily changed and it can beenlarged until its capacity equalsthe forty -three -plate kind.

The best part of this condenseris that it does not cost anything.The necessary material is a large -size business envelope, a piece ofcardboard big enough to slide into

22 E -Z RADIO

it snugly, the tinfoil from severalpacks of cigarettes or tea or choco-late and two ordinary wire paperclips.

The envelope used to build thecondenser shown in the picture wasthe standard No. 10 envelope usedby business houses and measured41/8 inches by 91/2. First I sealedthe flap and then cut the envelopeopen at one end. Next I took tin-foil and coated the whole envelopewith it with the exception of a nar-row margin next the open end.

In attaching the tinfoil to thepaper, do not paste it all over orelse the envelope will wrinkle bad-ly. Merely attach the corners witha little drop of mucilage.

Next I cut a piece of cardboardso that it would slide easily intothis envelope and this cardboard Ialso covered with tinfoil on bothsides.

The next thing to do is to cut along narrow strip of paper anddraw a scale upon it as shown inthe illustration. Any kind of scalewill do, but it is usual to divide acondenser scale into one hundredequal parts and that is what I did

ANOTHER VARIABLE

Get one of your smoking friendsto give you the tin foil from a fewpackages of cigarettes, beg anempty cigar box from the storearound the corner; get your wifeor your mother to make up a bitof ordinary flour paste, and find a

with this one. The 100 markshould come just at the edge ofthe envelope when the cardboardis shoved in as far as it will go.The zero mark should come to theedge of the envelope when the tin-foil on the cardborad has beenpulled out just beyond the edge ofthe tinfoil on the envelope.

Next I soldered paper clips tothe ends of two pieces of No. 28cotton -covered wire and one ofthese clips I shoved over the closedend of the envelope so that it wouldmake contact with the tinfoil andI used the other paper clip in thesame way on the end of the card-board.

In using this condenser it is bestto put a piece of board or a bookover it or inclose it in a folder ofcardboard so as to protect the tin-foil from damage.

The capacity of this condenseris varied by sliding the cardboardin and out 'of the envelope and, ifthe capacity is still not sufficientwith the cardboard shoved all theway in, it can be increased by put-ting a book cover over top of itand pressing down on it or puttinga heavy weight on it.

CONDENSER FOR YOU

brass bolt and a nut somewhereand you have spent all the moneynecessary for a perfectly good vari-able condenser which will be equalto the ordinary store one havingabout twenty-three plates.

E -Z RADIO 23

TIN FOIL

WRITINGPAPER

PAST DOWN5,10ork.

awnr-CAP

'UV I I I L NJ

TIN

Here is another variable condenser which any one canmake without spending a cent

If, howover, you want the equalof the forty-three plate kind, youwill have to go to the expense ofhaving to ask for more pieces oftin foil from your cigarette -smok-ing friend and getting two piecesof wood big enough to paste severalof these tin -foil sheets on each.

Smooth out the tin -foil as nicelyas possible before using, becauseit is always well to have all radioapparatus neat.

First it will be wise to give eachpiece of wood a coating of thinglue on one side and let it dry overnight. Then, in the morning, givethem another coating of glue andlay iour tin -foil sheets flat uponthem and smooth them down care-fully so that the tin foil will stickwithout wrinkles.

The tin foil should come all theway to and over one edge of eachpiece of wood, but should be aboutone- inch away from the opposite

edge and about one-half inch awayfrom the two sides. It does notmatter much about the size of thepieces of wood that you get, butyou should have at least thirtysquare inches of tin foil on each.If the tin foil which you get doesnot cover that amount of surface,you can paste pieces on wherevernecessary, but do not paste tin foilto tin foil as the mucilage is an in-sulator and we want good contactall over the surface of both sheets.In piecing out, paste the tin foil tothe wood and let the edge overlapthe other piece of tin foil and pressdown upon it.

With both pieces of wood thuscovered with tin foil, you paste anordinary sheet of writing paperover both surfaces to cover the tinfoil. Turn your two pieces of woodso that the paper covers come to-gether and pivot them with thebrass bolt in one corner of the sidethat is free from tin foil.

24 E -Z RADIO

You can now open and close theboards like a fan, and as you do soyou bring more or less of the sur-faces of the two tin -foil sheets overeach other. Draw an arc on thelower piece of paper and, when thetwo are opened as far as you canopen them, mark a scale runningby tens and units just like thescales on the regular dials of radio

sets and, as the edge of the upperone runs along this scale in tuning,you can see exactly at which markyou receive your signals best.

In using this variable condenserlet me say that you can consider-ably increase its capacity by put-ting a heavy weight of some kindupon the upper board.

GET READY FOR YOUR AMPLIFIER

off

PL

O

OO

-A)+0

FRONT VIEW

OUTPUT

B

A

Here are three views of achange you can make in youraudion control panel to pre-pare yourself for amplificationwhen you can afford the rest

of the apparatus

Most radio fans would have atleast one stage of amplification ontheir apparatus if it were not forthe fact that when they sit downto make up a list of the variousthings required the cost staggersthem. If they could only buy thestuff on the installment plan theywould go into it at once.

My object here is to show youhow to get the amplifier, althoughyou cannot use it until it is paidfor in full. I am going to tell you

LEFT SIDE VIEW

SIDE VIEWhow to mount a detector bulb sothat, as the money comes in, youcan add amplification, part by partwithout interfering with the fulluse of your detector bulb.

I am assuming that you haveadopted the 6 by 6 inch panels thatI have been advocating, and I amgoing to tell you of the changesthat I have made in several) ofmine, so that I can put them to-gether either for detector alone orfor one, two or three steps of am-

E -Z RADIO 25

plification. In changing yourpresent detector panel to preparefor your first stage amplifier, thefirst things to buy are a "double -circuit" jack and a phone plug.

Each one of these will cost youabout a dollar and you will neverregret the money that you spendon them because the plug and jacksystem will give you a totally newidea of how conveniently thingscan be arranged.

I am assuming that you have notyet bought the transformer and amadvising you to put in the jackand hook your phones to the plugpreparatory to getting the rest ofthe apparatus.

Later you can get the trans-former and mount it as shown in

the picture, and if you can affordto spend $6 now you can put it to-gether .and use your set until youhave saved enough money to buyan amplifying bulb, a socket and arheostat.

If, however, you do not care tobuy more than the plug and jack atpresent, put the jack where it is inthe illustration, rearrange yourbinding posts as shown in the frontview, lead a wire from the bindingpost marked "phones" to one bladeof the jack and solder it there,lead another wire from the bindingpost marked "plus B" on the rightto the lower part of the jack andsolder it there and then you can useyour bulb as a detector and havepart of the convenience of the plugand jack system at least.

WIRING UP YOUR TRANSFORMER

Here is a diagram which shows how to rearrange your detectorpanel to get ready for an amplifier when you can afford it

Assuming that you have bought detector panels ready for amplifi-a plug and jack and a transformer cation, I am giving here a dia-with the intention of getting your gram showing how the panel must

26 E -Z RADIO

be rearranged and wired in order.to function as a detector alone orelse automatically cut in your am-plifying bulb when you get it.

First you will see that I havemade a change in the binding postsdescribed before for your detectorpanel. We have now in the left-hand side three binding posts andon the right four. Some peoplehave five on the right, two for theplus and minus of the storage bat-tery, known as the A, two for theplus and minus of the B batteryand one for the "output" which willlead to the grid of the amplifyingbulb when you get it.

Personally I use only three bind-ing posts for the two batteries,using the same binding post for theminus side of both batteries asthey are virtually always con-nected.

You can do this wiring from thediagram if you wish, but I find thatthe average beginner has some dif-ficulty in this, so I am going togive you a list of the wires andtheir connections and you can workfrom this list independently of thediagram, checking each wire as youattach it.

First we must designate the fourblades which you will find on yourphone jack. Let us call the top oneA, the second B, the third C andthe lowest D. Now get ready 'toattach your wires and run themas follows:

From phone binding post ton leftto A blade of jack.

From plate binding post on leftto plate connection on the socket.

From grid binding post 'on theleft to one side of the grid con-denser and from the other side of

the condenser to grid binding poston the socket.

Now turn to the binding poststhe right side.

A wire from "output' bindingpost to binding post marked "G"on the transformer.

A wire from plus B battery bind-ing post to "B" blade of the jack.

A wire from minus binding postto binding post marked "F" ontransformer.

Another wire from that samepost to minus binding post onsocket.

A wire from plus A binding postto .one side of the rheostat and an-other wire from the other side ofrheostat to plus binding post onsocket.

A wire from B blade of jack toB binding post on transformer.

A wire from C blade of jack toP binding post of transformer.

It is absolutely essential to solderall connections to the blades of thejack and if you happen to have aparticular make of jack whoseblades are too close together towork comfortably take a pair ofpliers and bend them apart.

You are now ready to hook upyour panel to the tuning set andwhen you insert your phone plugin the jack you are cutting out thetransformer entirely and merelyusing the tube as a detector.

Later I will describe how to hookup another unit like this containingthe amplifying bulb, but I am as-suming that you do not care to goto the expense just now.

E Z RADIO 27

GETTING USED TO RADIO SYMBOLS

The corkscrew lines in the illustration show two electricalsymbols which indicate that two coils of wire are placed so asto have an effect upon each other. In other words, they indi-cate a coupler and the pictures show different types of cou-plers all of which are indicated in diagrams by these symbols.

If everybody understood all ofthe symbols used in the radiohook-ups and explanations given inmost of the text books and maga-zines, it would save our artist agreat deal of trouble in drawing thepictures which we use when wegive wiring illustrations for ap-paratus. The symbols are not atall difficult to understand, and it isvery convenient to be able to trans-late them, so it may be worth ourwhile at the present time to takethose which are most in use andlearn just what they mean.

We have already explained thata "coupler" consists of two coilsof wire placed in such a positionwith relation to each other that acurrent of electi:city flowing in onewill create or, to use the technicalterm, "induce" a current in theother, even though the wire of thetwo coils is not physically con-nected.

There are a great many differentkinds of couplers.

There is the old-fashioned "loosecoupler," which is a coil of wirewound around one clyinder and an-other coil of wire wound around asmaller cylinder which slides in andout of the first one. This slidingin and out "varies the coupling"-in other words, it changes the in-fluence that the electricity in thefirst coil has in inducing a currentin the second coil. This is ;ex-tremely important in getting sharpand distinct signals in the phones.

There is the type known as thevario-coupler, in which the first coilis wound around the cylinder andthe second coil is wound around aball -shaped form known as a"rotor." In this case the couplingis varied by turning the rotoraround on its axis inside the cyl-inder.

28 E -Z RADIO

Two spider -web coils or twohoney -comb coils or two coils ofany other kind which are used forthe same purpose also make acoupler, and changing their po-sition with relation to each other-sliding them apart like a fan c'ropening and closing them like abook-varies their coupling.

In all radio diagrams you willsee lines drawn in a fairly goodimitation of a corkscrew. This ismerely a graphic representation ofa coil. When two of these cork-screws are placed near to eachother in the diagram you will knowthat they are intended to have aneffect upon each other, and thiseffect is known as coupling.

TAP

Er.

TAP

In the illustration you will seetwo of these symbols representingcouplers. One of them has an ar-row striking through both coils ;the other has no arrow.

Nowadays these two symbolsseem to be used to mean the samething, but in the old days the sym-bol without the arrow in it wouldhave meant that the two coils werefixed in their positions with rela-tion to each other and that therewas no means of varying theircoupling. If we wanted to indicatetwo coils whose coupling could bevaried, we put the arrow cuttingthrough both coils. Whenever wesaw this arrow on any symbol weknew that it meant "variable."

SOME MORE ELECTRICAL SYMBOLS^ER IAL

GROuND---°

LOOsE C.Ovi.LER

SPIDER WEb

ta0Nt V cor-le

Here are the electrical symbols which indicate the aerial, thelead-in, the variable primary coil, the ground connection and

the fixed secondary coilIn our last talk on the symbols two corkscrew lines side by side

used in the regular electrical dia- which indicate a coupler.grams of hook-ups we showed the In the picture which we give

E -Z RADIO 29

with this article we are using thesetwo symbols again, but attachingto one of the coils, which is calledthe primary, the other symbolswhich go to make up what is knownas the primary circuit.

It starts at the top with thelittle inverted triangle, which al-ways means the aerial. Sometimesthis is merely a triangle, sometimesa line will be drawn from the mid-dle of the horizontal line down tothe lowest point, and sometimes theartist will add to this three littlelines jutting upward like the pointsof three lightning rods.

All of these symbols mean anaerial.

Coming down from the aerialyou will see a straight line whichindicates your lead-in and whichbends sharply at right angles tomeet the coil at the arrow point. Ithas become customary to lay out allelectrical diagrams at right anglesto avoid confusion of lines, but thisdoes not necessarily mean that thewire itself must actually be bentat a right angle.

In the symbol as we have givenit you will notice that the aeriallead-in meets the coil with anarrow point. Whenever you seean arrow in a wiring diagram youwill know it means "variable."

In some diagrams you will findthis aerial lead-in coming straightdown and being twisted at once intothe symbol for the coil. That willindicate that it is a fixed coil-onenot having any means of varyingthe number of turns included in thecircuit at that particular point.

In this one which we give herethe arrow indicates that you canvary the number of turns either bymeans of a rotating switch like theone shown on the variocoupler inthe illustration, or by means of a

slider such as you have on theordinary tuning coil.

Below the place where the aerialjoins the coil you will see anotherarrow point, which inidcates thatthere is another place at which youcan vary the number of turns ofthe coil included in the circuit.This particular symbol as givenhere might mean an old-fashionedloose coupler with two sliders onthe outer coil, or the modern vario-coupler with two switches as shownin the illustration or the two -tapped spider web coil which wehave been advocating so strenu-ously in these articles.

You will see that this lower ar-row is on a line which goes straightout to the left and then bends downto an inverted pyramid of horizon-tal lines. This pyramid of linesindicates the ground connection. Itmay be the cold water spigotsteam radiator (though I hope youare 'not using this for a ground) orit may be anything else that youuse to conduct your currents easilyinto the earth.

The right-hand corkscrew line inthe illustration is the symbol forthe secondary coil. As it is givenhere it would indicate the modernvariocoupler, because the absenceof any arrow points shows thatthere is no means of varying the

number of turns of wire includedin the circuit. The rotating ballwhich holds the secondary of thevariocoupler ordinarily has nomeans for this adjustment andtherefore would suit the symbol asgiven here.

If, however, there had been aline with an arrow point from thiscoil it would have meant that theparticular circuit given required anapparatus which had means of al-tering the number of turns of wire

30 E -Z RADIO

used in the secondary coil. Thiswould apply to the usual loosecoupler or the tapped spider webcoil.

Pick up any radio magazine orany book on radio and look at thediagrams and see how many partsof the symbols you can identify.

THE SYMBOL FOR THE AUDION BULBLEAK

401.:mmilmica

GRID CONDENSER

STORAGEii3AT

RM EO3TAT

Above you will find some more symbols used in diagrams inradio hook-ups and also pictures of the apparatus which will

enable you to translate themIn our past talks on the symbols

used in wiring diagrams as givenin virtually all radio magazines andtext -books, we have learned themeaning of the queer little figuresthat have been devised to indicateaerial, ground and various kinds ofcoils. Here we are going to takeup a group of symbols which arevirtually always found together inevery hook-up employing an audionbulb.

I am giving the hook-up first inthe form. of a diagram and thentranslating it into pictures of theactual objects as you know themand showing how the wires areconnected according to the dia-gram.

Let us take up the various piecesof apparatus part by part, refer-ring first to the diagram and thento the pictures. In the diagram a

line beginning at the left repre-sents a wire leading to one part ofthe audion bulb. The wire leadsdirectly to two vertical parrallwhich are not connected.

Whenever you see two lines ar-ranged like that, at right angles tothe wire and with an open spacebetween them, you will know thatthey mean a condenser. If therehad been an arrow drawn diago-nally across these lines it wouldmean a variable condenser becausearrows mean that that particularpiece can be varied. In this case,however, there is no arrow so itcannot be varied. We call that a"fixed" condenser regardless ofwhat size it may be.

From each side of your con-denser you will see lines going upand making a bridge with a saw-toothed line connecting them. A

E -Z RADIO 31

saw-toothed line like this in anyelectrical diagram means resist-ance-a piece of apparatus whichopposes the flow of electricity untilthe strength of the current is suf-ficient to overcome it.

These two symbols together inthis particular diagram representthe grid condenser and grid leak,as you will see in the picture.

If you will follow, in imagination,a current of electricity entering atthe left you will see that the con-denser stops it from flowingstraight through.

It builds up a form of energybetween the condenser plates untilthis eneregy is strong enough toovercome the resistance, when theelectricity flows around and gets tothe grid.

A grid leak may be either one ofthe standard kind sold in the storesor you can make it by drawing afairly heavy pencil line across thepaper of your grid condenser, beingsure each end of the pencil linemakes good connection with thebrass eyelets to which you fastenyour wires. This pencil line puts adeposit of lead on the paper andthis lead resists the flow of elec-tricity that is very weak, but acurrent of sufficient strength canpass across it.

Next from the grid condenserand leak in the diagram is a figurevery familiar in all wiring hook-ups that you will see-the circleand the three little symbols in itwhich mean the modern audionbulb.

As you know, there is inside theglass tube of the bulb a filamentthat lights from the current supplyof your storage battery. Thatfilament is represented by a hair-pin -shaped line which goes into thecircle of the symbol.

The zigzag line always meansthe grid and the little square oroblong means the plate connection.In the pictures, I am giving onlythe socket because the connectingparts are always mounted on thesocket and if you will hook yourwires to the proper posts as youwill find them marked you willknow that the right connectionwill be made when you insert thebulb in the socket.

You will see the hairpin -shapedline meaning the filament comesout of the circle at two places andthese places represent the plus andminus binding posts on yoursocket.

On one of these, as you will see,there is another saw-toothed lineand, as we have already learned,this represents resistance of somekind. You will see that there is anarrow touching this saw-toothedline and we know that an arrowmeans that the apparatus can bevaried. This, then. means a re-sistance that can be varied-inother words, a rheostat.

Down below this is a little groupof short and long lines. Symbolslike these always mean a battery.As this battery is connected to thefilament and rheostat you willknow that it is a storage batterybecause it is from that you getthe current to light your bulb.

It will really pay you to studythese two parts of the illustrationand to learn step by step whichpiece of apparatus is representedby each symbol in the diagram be-cause it is almost impossible tofind hook-ups in the picture formsI have been giving you, and youmay find articles in radio maga-zines that you would find very in-teresting if you could translate thesymbols.

32 E -Z RADIO

THE SYMBOLS FOR A MODERN HOOK-UP

Here is a hook-up given in diagrammatic form and the mean-ing of the symbols is explained in the accompanying article

We are ready now to try to trans-late into ordinary terms the sym-bols used in a complete diagram ofa modern radio hook-up.

The one given here shows themethod of connecting the instru-ments for the standard "short-wave regenerative" set, and itcontains most of the symbols to befound in any hook-up.

Let us begin at the very begin-ning and take up each symbol.

In the upper left-hand corner isa triangle with a line drawnthrough it. This represents theaerial. The line goes down, bendsto the left, goes down again andends in a little arrow point. Anarrow point, as we have alreadylearned, means that the apparatuscan be varied in some way, and thefact that this hook-up shows the

aerial connected to this variablepoint would indicate that the wireleading into this instrument goesdirectly to a shaft holding a switchblade.

The two corkscrew lines set neareach other represent two coils ofwire and the arrow striking be-tween them shows that the po-sition of these two coils with ref-erence to each other can be varied.This would mean a vario-coupler ora loose coupler or a pair of anykind of coils used as a coupler.

The coil on the left is, of course,the primary and the bottom line ofthe coil leads down to the invertedpyramid of horizontal lines whichis the symbol for the ground con-nection.

Most vario-couplers have twoswitch blades, one of them govern-

E -Z RADIO 33

ing the taps by single turns of wireand the other governing the tapsby larger sections and, if that isthe kind to be used, the line in thesymbols leading to the ground con-nection, instead of coming directlyfrom the coil, might have had anarrow point on it the same as theline coming from the aerial. Butin many such hook-ups an arrowpoint simply indicates variability,and it makes no difference how thevarying is done. It might just aswell indicate the sliders on the out-side of a loose coupler. The primeobject of the symbol is to tell youthat the aerial and the ground areto be hooked to one coil of wire,with some means of altering thenumber of turns of wire that youuse, and that this coil is placed nearto another coil in such a way thatthe magnetism of one will affectthe other and with some meansprovided for varying their positionwith respect to each other, andconsequently varying the magneticeffect which one has on the other.This varying position is what wecall "coupling."

The second corkscrew line rep-resents the other coil of your coup-ler and, as there is no arrow pointone the lines going out from it, itmeans that it is not necessary tovary the number of turns used inthis particular coil.

The line leading from the top ofthe second corkscrew curve goesdirectly to the only unfamiliarsymbol that there is in this dia-

gram. This is the cross formed bytwo saw-toothed lines, and I amgiving it here in this form becausemany publications print it thisway, though it is not strictly cor-rect. A cross like this with theends of two of its arms connectedby a line indicates the instrumentwhich we call a variometer.

To be strictly accurate, the twoarms of this cross should have beenmade to look like Mary Pickford'scurls. Saw-toothed lines, such asare given in this diagram, oughtalways, to represent some kind ofresistance, and a variometer is nota resistance. A variometer is twocoils of wire, with the end of theouter coil connected to one end ofthe inner coil, and I am giving thewrong symbol here deliberatelyonly to point out the fact that itmeans a variometer as given inmany publications whose editorsare not sticklers for accuracy.

Beyond this symbol for a vario-meter we see the two parallel lineswith a space between them whichwe know represents a condenser,and we see that the line from thiscondenser leads into the circle rep-resenting the audion bulb to thejagged line which represents thegrid.

In wiring up this part of the dia-gram we would attach one end of awire to the secondary of the vario-coupler and the other end to oneend of the variometer. We wouldattach another wire from the otherconnection of the variometer to

34 E -Z RADIO

one side of the grid condenser andanother wire from the other sideof the grid condenser to the bind-ing post marked "G" on the bulbsocket.

Let us now turn our attention tothe lower end of the corkscrewline in the coupler. This leads di-rectly to the right, to the series ofalternate long and short lines,which means a battery. Abovethis battery you will see anothersmaller group of these lines con-nected to the hairpin line runninginto the audion bulb. This . hair-pin line represents the filamentand, as the smaller group of linesrepresenting a battery is connectedto this hairpin line, we know thatthis smaller battery means thestorage battery, because that is theone which lights the filament. Thesaw-toothed line between the bat-tery and the bulb touched by anarrow point which indicates vari-ability represents the rheostat bywhich we control the amount ofcurrent used to light the bulb.

It will be seen that the two bat-teries are connected to each otheron one side and even when a dia-gram does not indicate which is theplus and which is the minus side,the beginner is always safe in con-necting the two minus sides to-gether. I have seen many hook-ups giving a connection betweenthe minus side of the B battery andthe plus side of the A battery, butI have usually found it improvedby connecting the two minus sides.

Going down again to the lineleading from the secondary coil, onpast your B battery, we see it con-nects to one side of the telephonesand that same side of the tele-phones connects also to one side ofa condenser.

The other side of the telephonesconnects to the other side of thecondenser and also to another ofthose cross -shaped symbols, mean-ing a variometer, and the connec-tion from this variometer goes di-rectly to the plate inside the audionbulb.

THE SYMBOLS FOR A TWO -SLIDE TUNER

It ought to be easy now for anyof the readers who have been fol-lowing these articles to hook up anaudion bulb and a two -slide tunerfrom the diagram given on thenext page.

First, we know that the longcorkscrew line means a coil and thetwo arrow points touching it meanthat it can be varied at two con-

nections. As one of these con-nections goes off to one side, lead-ing to the ground, and the othergoes off to the side leading to thebulb, we know that these are notmerely the tens and units switchesof the vario-coupler because thoseswitches only lead between aerialand ground.

E -Z RADIO

This is the technical diagram representing the hook-Lp for atwo -slide tuner and an audion bulb. The meaning of thesymbols and the methods of connections are explained in the

accompanying article

This is the two -slide tuner whichis the favorite instrument of somany- beginners and bythe way, a very efficient and easilymanaged piece of apparatus in thishook-up. Let us read this diagramfrom the top and see what theconnections are.

The triangle at the top meansthe aerial and the line leading fromit to the top of the corkscrew curveshows that the lead-in of the aerialis connected to one end of the two -slide tuner and the line going tothe right shows that the same endof the tuner is connected to thegrid condenser and leak repre-sented by the two vertical lineswith the saw-toothed bridge overthem and that the other side ofthis condenser and leak is con-nected to the grid binding post onthe bulb socket as represented bythe saw-toothed line (which means

the grid) inside the circle (repre-senting the bulb).

The first arrow -shaped line leadsdown to the inverted pyramid ofhorizontal lines which always rep-resents the ground and this meansthat one of your sliders should beconnected to your cold -waterspigot.

The other slider represented bythe arrow -point shows a line con-necting to the hairpin symbol in-side the circle and, as this hairpinline always represents the filament,and you can see by following itthat the side to which the sliderconnects also is connected to theminus sign on the battery, youknow that this means that you areto run a wire from the secondslider to the binding post markedminus on the bulb socket and thatyou are to run another wire con-

.

36 E -Z RADIO

necting to these two from theminus side of your battery.

This double connection may bemade at any place you see fit. Itis really a triple connection becauseyou will also see that the minusside of the B battery is in the samecircuit. Personally, when I havefour or five pieces of apparatusthat are connected together in thisway, I cut a little strip of tin froma tin can and solder the connec-tions to it making it the commonconnecting point.

Thus, in this particular instance,I would run a wire from the sliderand solder or screw the other endto the piece of tin. I would runanother wire in the same way fromthe minus binding post on the bulbsocket to the piece of tin, anotherwire from the minus side of thestorage battery to the piece of tinand still another wire from theminus side of the B battery to thepiece of tin.

This idea will be found an ex-tremely useful one and it reallymakes for efficiency, because, whenyou put more than one piece ofwire around a binding post thethumb screw is almost certain tocome loose in time and a loose con-nection of this sort is the lastthing you think of looking forwhen you are having trouble ingetting your signals, though it iswise always to look for loose con-nections first when anything hap-pens.

The lower end of the two -slidecoil is shown connected to anothersymbol containing two verticallines with a space between, whichwe know indicates a condenser, andthe arrow striking through itmeans it is a variable condenser.

There is another line represent-ing a wire running from the vari-able condenser to one side of thetelephones and this line shows stillanother connection or branch com-ing off of it and running around tothe plate binding post on the bulbsocket.

A single branch like this is bestmade by scraping away the insula-tion on a part of a wire, twisting,the end of the branch wire aroundthe bare place, fixing it with a dropof solder and wrapping the connec-tion with insulated tape or paintingit with shellac or hot paraffin.

The other side of the telephonesis shown connected to the plus sideof the B battery.

The plus side of the storage bat-tery goes up to the arrow pointtouching the saw-toothed line and,as we know a saw-toothed line likethis means resistance and thearrow means that it is variable weknow that this symbol representsthe rheostat and that it is hookedup between the plus side of thestorage battery and the plus bind-ing post on the bulb socket.

E -Z RADIO 37

A GLOSSARY OF SYMBOLS

AERIAL

AtinioribuLD

-11111111- BATTFRy

CHOKECOIL

COIL(FIXED) I --

COILTAPPED

COILTwO TAPS

COILSCOUPLED

COILS WITHVARIABLECOUPLING

CONDENSER(FIXED)

4..K CONDENSER ..AwAv.- ItESISTANteVARIABLE

(F I xio)VARIA6Le

-Witt- IIIGSISTAryC02.4fiosrAr)

CONDENSERAND LEAK

SWITCHDET 6CTO R(CRYSTAL.)

milligAmPtiFyin6TRANSFORMER

WvAIZIOMETERGROUND

Prior -4E5 eF winesi DO IOT JOIN

This collection of symbols will enable the amateur to translateand understand any of the ordinary diagrams of radio hook-ups

In our studies of the electricaldiagrams used to represent varioushook-ups, we have come acrossmost of the symbols which theradio fan will encounter in anybook or magazine on the subject.

In this article I want to make arapid summary of these symbolsand I am giving in the illustrationthe separate signs used to indicatevarious parts of apparatus.

The symbol representing theaerial is sometimes varied by run-ning two little straight lines up-ward from the corners of the tri-angle. Other writers do not usethe triangle at all but change itinto a square form with two orthree uprights like the points oflightning rods. The differentvariations, however, are easilyrecognizable and the amateur willfind no difficulty in identifyingthem.

The sign for the audion bulb isthe circle with the three little fig-

ures in it. It is most convenient toregard this sign as representingthe socket. These sockets are nowstandardized and have four screwsor binding posts on them to whichyou attach your wires.

One of these screws is marked Gand is indicated by the little saw-toothed line in the symbol whichrepresents the grid inside of thebulb. When you screw the bulb inthe socket, it automatically makescontact with the binding postsmarked G.

There is another binding postmarked P and this is indicated bythe little square or oblong insidethe circle which represents theplate within the bulb.

The hairpin -shaped line repre-sents the filament and, as it comesout of the circle in two places, thisshows that there are two bindingposts to which it is connected.On some sockets these screws aresimply marked F but on othersthey are marked plus and minus.

88 E -Z RADIO

In any electrical diagram youcan tell which is which by followingthe lines down to the symbol whichrepresents the storage battery andseeing to which side of it they areattached.

The choke coil symbol will not befound in the simple forms of dia-gram but is used in the new Arm-strong super -regenerative circuit,in all transmitters, and in some ofthe more elaborate forms of re-ceivers.

Given as shown in the illustra-tion, it indicates a coil woundaround an iron core; without theparallel lines cutting through thecurved lines, it means a coil of al-

no core andmay be honeycomb, duo -lateral, ora single layer coil.

The illustration gives a numberof symbols representing inductioncoils. The first one is a plain coilwith no means of varying the num-ber of turns of wire that you use.The next one, with one arrow pointtouching it, means that there is aswitch or slider by which wechange the amount of wire that weinclude in our circuit. The nextone, with two arrow points, means

THE WORKINGS 0It is so important for the begin-

ner in radio to understand how acondenser acts and why it is usedin radio that I am glad to print herea letter from a reader containingone of the clearest illustrations

that there are two such switchesor sliders.

The symbol with the two coilsplaced near each other means thatthere are two coils in such a po-sition that the magnetism aroundone creates an electrical effect inthe other and this makes what wecall "coupled coils."

Strictly speaking, the symbol asgiven here means that there are noprovisions made for changing thecoupling-in other words movingone coil farther from and nearer tothe other. This ability to changethe coupling is illustrated in thenext symbol which shows the twocoils with an arrow strikingthrough them. But most booksand magazines nowadays havedropped this arrow and use theother symbol to represent coilswhose coupling can be varied be-cause they are really the only kindof coils that are used in modernsets.

All of the other symbols explainthemselves and it will be a per-fectly simple matter for the ama-teur to read almost any diagramby means of this glossary.

F A CONDENSERthat I have yet seen. The writer isGeorge T. Prince, a consulting engi-neer of Omaha, Neb., and a memberof the American Society of CivilEngineers. Mr. Prince writes:

"Referring to what you published

E -Z RADIO 39

relative to condensers, you compareit to a tank storing water, remark-ing that as soon as the tanks werefilled to the overflow pipe the read-ers are supposed to understand bysome method the bottom of thetank is to drop out and the amountof water stored in the tank to bedelivered in mass.

"It occurs to me that you wouldbe interested to know of the 'flushtank' which is employed in sewersystems. You will recognize thatsmall branch lines of sewers, par-ticularly when laid on flat grade,will not, as a rule, carry sufficientsewage known as 'dry weather flow'to prevent the pipe from becomingclogged and foul, and to guardagainst this possibility we place atthe head or upper end of such alateral a device known as a 'flushtank,' which is simply a closed tankusually built of brick and sealedwater -tight with cement, which re-ceives water from a service pipeconnected with the water main, theflow being regulated by a valve.

"In this tank is placed a verticalpipe extending to the elevation ofthe maximum water line and whenthe water reaches this pipe it over-flows into the sewer below. Aroundand over this pipe is placed a pipeof larger size, the bottom of whichis placed at elevation of low watermark, within a few inches of thebottom of the tank, the top beingclosed and extending a few inchesabove the top of the overflow pipe.

"In operation, the water rises inthe annular space between theouter envelope and the dischargepipe until it reaches the top of thedischarge pipe and flows downwardthrough the same. Without goinginto details, suffice it to say that

this downward stream of water ex-hausts the air within the dischargepipe, setting up a siphonic actionthat results in discharging the con-tents of the tank in the fraction ofa minute, the usual amount con-tained in the tank being approxi-mately one hundred gallons.

"This flush of water down thesewer lateral overcomes the tend-ency of clogging above referred toand these flushings can be made asoften as is necessary by regulatingthe flow of water into the tank byregulating the aforesaid valve. The'flush tank' is then a good illustra-tion of a fixed condenser.

"I believe there is yet a betterillustration by comparing the con-denser to the ordinary pile drivingapparatus, in which a weight israised through the leads to any de-sired height and then tripped.

"During the first operation ofdriving a pile the weight is raisedto the entire height of the leads,where it is automatically tripped,and as the pile reaches the eleva-tion at which it is desired to drivethe same, the height to which theweight is raised is decreased so thatthe effective blow upon the pile willnot be sufficient to drive it belowthe desired elevation. This illus-trates a variable condenser.

"In the first instance, potentialenergy is stored in the 'flush tank'and delivered by the discharge ofwater; in the second instance,energy is imparted by the fallingweight. In the electric condenser,as I understand it, electric energyis imparted by the current fallingfrom a higher to a lower potential.It occurred to me that the abovereferences might be of interest toyou."

40 E -Z RADIO

YOU MUST LEARN TO CRAWL FIRST.

To the far-seeing man in the radio industry, nothing ismore discouraging than the widespread advertising campaignto force the novice to buy the most elaborate and expensivekind of radio apparatus under the impression that it is sosimple a child can operate it and so efficient that you and yourfriends can hear opera and concerts and lectures as plainly asthough you were in the hall with performers.

Neither of these assertions is true. The set with threestages of radio frequency amplification, detector, two stagesof audio frequency amplification and three five -watt tubes onan electrical loud speaker cannot be operated satisfactorily bythe beginner. It takes an experienced and clever man tooperate it. And even then it will never give you the illusionthat you are actually in the hall with the performers.

Radio hasn't reached that stage yet and this advertisingis leading hundreds of buyers into the science through falsehopes that are not realized and the buyers quit in disgust.

The beginner must crawl before he can walk. He shouldstart with simple apparatus and with the books that explainit in language understandable by a child. And, as he graduallyabsorbs the knowledge of the hows and whys of radio, he canadd to his apparatus and elaborate upon it and all the time getthe fullest measure of satisfaction from it.

E -Z RADIO is intended to teach you to crawl. From thefirst (May) issue, it has gradually led up from the simplestbeginnings to the things you see dealt with in this number.But you will lose half the enjoyment and value of this andsucceeding issues unless you start at the very beginning.

Send one dollar to this office for a six months subscription,instructing us to enter it from the May number.

E -Z RADIO,

614 Arch Street,Philadelphia.

BRING YOUR TROUBLES TO US.

Every beginner in radio runs into a snag in his early days.Something doesn't work and he isn't sufficiently expert in thescience to locate the trouble.

Perhaps he buys some advertised goods and, when hegets them, can't find out how to hook them up.

Maybe he has some apparatus and thinks he might im-prove it by adding a variometer or a variable condenser orchanging his hook-up. Maybe-but he isn't sure and hewouldn't know how to go about it if he were.

And so he writes to Mr. Neely.

You who buy this issue of E -Z RADIO have this privilege.We want you to feel that this is a magazine of RADIO SER-VICE and, no matter what your problem and no matterwhether you are a subscriber or not, write to Mr. Neely andlet him do your puzzling for you.

Kindly enclose a stamped, self-addressed envelope forreply. Address,

HENRY M. NEELY,E -Z Experimental Station,

Delanco, N. J.

DEPENDABLE

DIAMOND QUALITYLINE

ESTABLISHED1909

Pioneers in ConStrudingElectrical Instruments

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No. 41

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