History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Wireless Weekly/Issues/1922 08 25 - Wikibooks, open books for an open world (2024)

scan of Australasian Radio World - Vol. 01 No. 04 - August 1936 has been utilised to create the partial content for this page and can be downloaded at this link to further extend the content and enable further text correction of this issue: ARW 1936 08

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The Hundred per cent. Australian Radio Journal.

THE WIRELESS WEEKLY

A Journal Devoted to the Interests of Wireless Enthusiasts both Amateur and Professional

Vol. 1 — No. 4; SYDNEY, AUGUST 25th, 1922. Price — Threepence.

Cover Photo: Sketch of Antenna for New Station at Belgium (see page 4)

Advertisem*nt: Wireless Electric Company, Beach Street, Coogee, N.S.W. We Specialise in Complete Radio Receiving Sets and all Parts.Write or Phone for Particulars. PHONE 368 & 369 RANDWICK.

ELECTRICITY HOUSE.387 GEORGE STREET (OP. STRAND). TEL. 2961 CITYFOR ALL RADIO SUPPLIES.We cater specially for the amateur. Expert advice given free.All and any Gear made to order. Large Stocks always on hand.Complete Outfits from £5.HONEYCOMB COILS, from 6s. 6d. CONDENSOR PLATES, from Is. 6d. doz.Knobs, Dials, Eheostats, Switch Arms, Ebonite and Bakelite Panels, Cabinets, etc.Switch Points, 2£d each. Polished English Ebonite Dials, 3s 9d each.All Crystals, 6d and Is. Crystal Cups, Is 3d each.Our Rotary Switch Arms are a decent job at 4s 6d.Sliders (for Tuning Coils), Is 9d. Terminals, 6d each.Get your name down for a Catalogue. Price 6d.Absolute Satisfaction Guaranteed.

A TALK WITH "WIRELESS WEEKLY."A couple of weeks ago we made a suggestion to the authorities, that the nightly weather reports, now sent out from Australian coast stations by Wireless telegraphy, should also be broadcasted by radiophone for the convenience of people in the country districts.Of course, it is hopeless to even think that the scheme has been considered as yet; it takes time for the average Australian politician to grasp anything in the nature of progress. But it must be done.For months past now France has been giving out weather forecasts and reports by Radiophone, realising that every Citizen, if he cares to use a simple receiving set, is entitled to the benefits of a national utility.America, too, though her wireless affairs are not all that could be desired, is in the van of progress. Even from conservative England comes a report that wireless weather reports sent out in Morse code have been slowed down so that the amateur, who is not an expert telegraphist, can intercept them.Here in Australia, the continent of zvide spaces, the agriculturalist and the pastoralist are deprived of the thrice blessed gifts of science.WhytBecause the authorities are not abreast of the times in these matters. It is all very well to say that the man on the land has no apparatus to receive the reports. If he knows that the reports are to be broadcasted, he will soon get the comparatively inexpensive set to receive them.It is likewise futile to say that the radiophone is not efficient, for an amateur only a few weeks back, succeeded in getting speech from his Sydney station to New Zealand, using under nine watts power.There is no reason for the authorities to delay another week.Garden Island Radio, Sydney and the Melbourne Radio are equipped with the necessary apparatus. It is the intention of “Wireless Weekly” to have questions onthis subject asked, in the House of Representatives . The replies will be interesting.The Federal elections are fast approaching; the Government cannot afford to ignore or shelve such an important matter as this.SOMETHING TO DOHere is the method of roughly calculating the wave length of an aerial: W.E. in metres equals L multiplied by 4 point 6, over If point25. “L” is the total length of the aerial in feet.The approximate wave length of an aerial is 4 h time** its length, inclusive of the lead in and ground lead. This applies To~the inverted“E” type. For the wave length of a tone “T” type, the length of the aerial is divided by two, after which the lead in and ground lead lengths arc added.

COMPETITION COUPON.To the Editor,Sir, —Herewith photograph and description of tny set as an entry for your competition.I agree to be bound by your decision, and Observe the rules of the competition.'(Name) ..,(Address)(If under 18 years of age)AMATEURS!Let us show you hq&v to make your own set, and economise.We stock all Parts and will give you every assistance.Wo Specialise in all Loose Coupler PartsCountry and Interstate amateurs, take advantage of ourSame Day Service.Miss F. V. WALLACE,Electrical Engineer,S Royal Arcade (opp. Q.V. Buildings),George Street, Sydney.A PECULIARITY.BODY INDUCTANCL.Do you know the meaning of “body inductance?”In radio reception the body has a jueciii.m cnaracteristic of acting as an inductance of very great resistance or as a capacity of low value (says “Popular Science Siftings”). As an inductance you can obtain results by disconnecting the aerial from the apparatus and holding the aerial in one hand and touching the antenna terminal of your apparatus with the other hand. In the case of nearby broadcasting stations, where you are using the vacuum tube detector with two stages of amplification, fairly good loud reception can be obtained by placing the body in series with the antenna and the apparatus.To do so, however, is merely an experiment, and it has no value, as it materially reduces the strength of the signals. The body will exert a capacity effect if the hands are placed across certain of the terminals in your set.For instance, if you place your finger on the grid and plate terminals of your vacuum tube the body will act as a condenser, giving a slight feed-back from the plate circuit to the oscillatory circuit, and a slight increase in strength will be observed on vacuum tube sets that are not regenerative in themselves.This body capacity effect is sometimes the cause of a great deal of inconvenience, particularly in sets using vacuum tubes, where the set itself is not ground-shielded. The annoyance consists of the fact that after the operator of the set has completed the tuning arrangements and withdraws his hand, the whole* set is thrown out of adjustment. This is caused by the removal of the small amount of capacity represented by the body out of the circuit when the operator withdraws his hand.Don't try to solder your earth wire to a water pipe, its most difficult. The best plan is to hold the wire to the pipe by means of a clip.BEST SET.WHOSE IS IT?A COMPETITION.“Wireless Weekly” is conducting a competition.We are looking for the best amateur crystal set, and the bestamateur valve set.Of course, it would be impracticable for us to examine the actual sets, so the judging will be on a,photograph and written description.There is no entrance fee..All you have to do to enter a set is to get a good clear photograph of it, and send it, together with a description and details, notexceeding 200 words, and the filled out coupon on this page to the Editor, “Wireless Weekly,”Fox 378, G.P.O., Sydney. Envelopes should be endorsed “Competition.”It 'makes no difference if you made the set yourself or not.Judging will be on design, neatness and originality, and in order that the judges may have full information to work on, competitors are asked to send good photographs, and clear manuscript, written on one side of the paper only..The prizes will be an open order to the value of one guinea, on any establishment selling wireless apparatus, for the best crystal setand best valve set.The competition will close on September 22, when all entries must be in the hands of the editor. All photographs and entries sent in become the property ofthe “ Wireless Weekly.”Competitors must give their full names and addresses, but if it is expressly stated these will be held confidential.In all case's, and on each and every point, the decision of the Editor shall be final.POLDHU.FAMOUS STATION CLOSES.Poldhu, probably the most famous wireless station in the world, has sent its last messages, says the London Daily Mail. M.8.D., its famous call sign for which ships’ operators have listened eagerly for the last 19 years, is now replaced by M.F.T., the sign of Clifden, the Irish station of the Marconi Company.Perched on the rock-bound coast of Cornwall, Poldhu, which has made history, was the first high-power wireless station to be built, and from here the first wireless message was sent across the Atlantic on a 2,000-metre wave- length on December 12th, 1901, to St. John’s, Newfoundland.The future of the station is not yet certain. It is probable it will be used for research work, but never again will messages from the far ends of the earth be received marked, ‘via Poldhu.”

HOW TO START AVOIDING PITFALLS BY ONE WHO HAS SUFFERED.The average man • hears a lot about “experimenters'” and “amateurs,” these days. He reads of their doings, puzzles over their technical jargon, and, perhaps wishes he too would take up this fascinating hobby.Then the problem confronts him: “How do I start?” If the prospective enthusiast has a friend already “in the game” his path will.be easy, but if not it is the . reverse. The writer caught the -radio disease from a stray technical publication and went entirely the wrong way about getting a set.Fortunately I saw a newspaper paragraph telling how and where to apply for a license, and having got a covering letter, and with permission to experiment I set about looking for apparatus.From the teennieal' book I had gleaned a very misty' idea of the parts required, and not wishing to show my Ignorance, I copied out the bit and read it to the shopkeeper.i’liO ITJ ih K ■ STARTS.. That, was all. right, but when I got the parts home my troubles commenced. I connected up, but could get no-results, and after wasting a deal of time and exhausting all my patience, I reluctantly gave up. At that moment, radio was very near to losing me. However, I pocketed my pride, went back to the shop.There was a gleam in the shopkeeper’s eyes when he saw me; I think he understood. Frankly I told him all and he kindly gave me a lot of hints and changed the parts for a nice little crystal set.He also introduced- me to some experimenters, wh© i got me into their club. At the club meetings I learned more than, anyone could from text books.WHAT TO DO,I have now reached the valve stage, and derive the maximum of pleasure from my experimenting,but I shall never forget my inglorious entry into the game.Now this is my advice to any person who washes to start experimenting. Write to the Secretary of a club and ask him to get you elected. Don’t be afraid to ask the members for advice; theywere all beginners once. Writestraight away for a license, and when you get it, choose your apparatus. Ask one of your club-mates what to get and let them help you instal it.Thereafter your progress should be rapid and straight forward.WE PROMISED.(By LOO NATIK).A man with a wild look in his eyes and straw in his hair bustledinto the office of the “Wireless Weekly,” the other day. While waiting for the attendant to arrive he scribbled the followinglines and asked the Editor to publish them. The Editor (belonging to the clan that boasts of beingtoo proud to fight, and, incidentally being too fat to run) promised, so here you are: —T’was Christmas Day in the “NutHouse”The loonies were all there,Watching a fellow patient,Tearing his flowing hair.I’ll tell you who he was, sir,And why he worried so;His name was Grid Condenser,The cause was Radio.I’ll tell you the harrowing story.And how he got put in,He tried to make a sending set,With a matchbox and a pin.There are thirty five moreverses, but the Editor, now that his friend is in good hands once more, does not feel disposed to inflict them on our readers.“ *Keep your accumulators upright. Sulphuric acid has an in-desirable effect on one’s best carpet.FOR BELGIUM.Monster Station.(See Front Page).Our front page •- illustrationshows the giant station the Belgian State has just started at ' Ruysselede, near Bruges. This plant, is intended to communicate with the Belgian colony in! Central Africa, as well as with North andSouth America. It will perhaps be the most powerful in the world.The aerial is to be supported by eight towers 0f 2 75 metres height.The power plant will consist of one 1000-kilowatt generator, with two high-frequency generators of corresponding power. One of these will be an arc generator, weighing8 000 kilograms; the second will be a high frequency alternator of the Bethenod-Eatour system.The second of these will work at 2500 turns per minute, giving a peripheral speed of 170 metres per second for the rotor. It works in a partial vacuum to reduce the resistance. Rotor and stator are to be cooled by oil circulating under pressure. The length of waves in both instances will be from 20,000 to 25,000 metres; current on the aerial, 850 amperes. Automatic transmission at a speed of100-120 words per minute will be employed.The building of the plant has been entrusted to the same Belgian concern that is now engaged on the Belgian stations in Central Africa.The drawing gives a view of theplant with its huge aerial as originally designed, although some modifications of this design are under way.<s—Hang the phones on a wall when you have done with them. This allows the moisture on the diaphragms to dry. Never tap the diaphragms with a pencil. Once they get bent they are useless.See that your valve circuits are not causing radiation. By this is meant, don’t experiment withe circuits until you know.: you are doing.

MAKE YOUR OWN.A LOOSE COUPLER SET.A simple and effective loose-■coupler crystal set is shown here, and for the expenditure of a few shillings, and by following out the directions, a wireless set may be constructed, which will have a range of about 2,000 miles, with a good aerial, and a wave length of over 2,000 metres.with a set of this kind, you should have no difficulty in hearing Awanui, New Zealand, and most Australian stations, and you will be able to listen to the concerts, if favourably situated.Get two cardboard tubes, about seven inches long, and 41 inches and 4 inches in diameter respectively, and give them a good coat of shellac, first making sure that they are thoroughly dry.Wind the larger tube, the primary with 24 or 26 gauge enamelled wire, a single winding being all that is necessary, and mount the tube between two square piecesof wood, P and P’ , P’ having a circular hole in it, to allow the secondary tube to slide inside the primary.A brass rod and slider are mounted on top of the primary as shown, the slider “a” making contact with the primary wire along a track from which the enamel hasbeen carefully .scraped from the wire, so that as the slider is moved along the rod, contact is made with each wire separately. 1 A terminal is fixed on the slider rod at “x,” and another terminal is placed in a convenient position, on the other wooden end at “y,” and one end of the primary winding is connected to “y.” The other end of the primary wire is secured to the cardboard tube, but is not connected to any terminal.It is a “dead-end.”The terminal “y” is the aerial terminal, and it is here that you join your aerial wire, while “x is the earth terminal, and is to be joined to a water pipe or other suitable earth. It will be readily understood that the current from the wireless waves comes from the aerial to “y,” passes through the primary winding to the sliding contact a, in whatever position “a” may be, then along the slider rod to “x,” and so to earth. This is the complete primary circuit. By moving “a” nearer to “x” a longer length of the primary winding is brought into use, and these extra turns give you a longer wave-length.Ordinarily, with “a” about one inch along the windings from “y,” the commercial 600 metre wave length would be picked up, so that get a concert wave of say 1,400metres, you would need to slide“a” about $ of the way along towards “x.”Now for the secondary winding, “b.” First of all, make sure that you are winding “b” in the same direction as you wound the primary, as shown by the arrows. Use No. 20 gauge silk or cotton covered wire. Begin at the left hand end, and wind for about one inch, and then make a hole in the cardboard tube underneath, and putting your hand inside, draw the wire through Inside the tube, in a long loop ready to connect to the first stud “c” on the left of the group of studs. Then wind along for about another inch, and repeat the looping of the wire, this time connecting to the second stud, and so on, until the end of the wire is fastened to the last stud. Any brass bolts and nuts may be used as studs, but be sure to leave a generous length of wire when, making your loops for connection to these, and if possible, solder the connections. A knob and switch-arm “d” are used to make contact with the studs, and are fixed as shown.The secondary is mounted on two brass rods “f,” which pass(Continued on page 6).

aWestern ElectricA MOST EFFICENT HEADPIECEOVER A WIDE FREQUENCY RANG!A light and comfortable, especially built Radio Accessory, designed to reproduce over a range from the low notes of a church organ to the high vibrations of a violin. You’ll find Western ElectricNo. 1002-c. the finest headpiece you’ve ever used. Call and inspect it, or write for particulars.WESTERN ELECTRIC COMPANY(AUST.) LIMITED192 Castlereagfi Street, Sydney.262 Flinders Lane, Melbourne.aELESS SPECIALTIES - GUARAhTEEl) & SENT ANYWHERE.Get our Catalog, 80 pages,200 illustrations.Price 7d. post paid.POTARYSWITCHARMS, with Ebonite knobs. 3s. each.Postage 3d.SWITCH POINTS. Price 4d. each, post paid.SLIDERS (for Tuning Coils),P s -( * d.Wireless Hook-ups 88 page Book, 157 diagrams.Post paid Is. 3d.DETECTORS (Dust- proof). Illustrated. 255.BABY (Simple and Reliable. ss.SILICON or GALENACRYSTAL (tested). Is6dCRYSTAL CUP, with3 screws. Is. 6d. Postage lnd.PHONE or GRID CONDENSER. 2s.utTlx/f^rLUi\r

21/ **U/AISJSTON STREETthrough the primary and secondary ends, and are secured with nut 3 as shown at “n,” one end being fastened to a small wooden upright “g.”The whole is fixed to a base-board “r,” and screwed firmly in position.The secondary is provided with two circular wooden ends, which should have been previously mentioned, the brass studs and switch-arm being mounted on one of these ends. “L” is a piece of ebonite fixed on the sides of the primary ends, and on it is mounted a simple phone condenser “K,” the construction of which will be described in the next issue, and a crystal cup “j” with a catwhiskcr contact.The telephones are connected to two terminals “t,t”- on the phone condenser, and the secondary circuit is completed by taking one wire from the switch on the secondary to the terminal Holding the catwhisker contact, and another wire from the beginning of the secondary end (which is otherwise a free end) to the top terminal of the telephone condenser, then connect with a short wire, or brass strip, from the crystal cup to the bottom terminal of the condenser.The wires from the secondary could be brought around through the back of the primary and then behind the ebonite panel. They are not shown on the diagram.This set is more efficient, and gives finer tuning than that described in our last issue. The loosecoupler has the advantage that when the amateur goes in for valve work he can still use it incr •■'nr-tinii with a valve panel.CHILD OF 5 MAKESA LOOSE COUPLER.Little Rex Roy, aged five years, of Sydney, has just completed a loose coupler set, with a wave ■ length up to 2,000 metres, and a very creditsable job it is.He built the set absolutely unaided except for advice, and when he and his father brought the set into the city the other day, it was connected to aerials, and found to give excellent results.Rex’s chief sorrow is that he has to go to bed: before Pennant Hills sends his weather reports every evening, but daddy has strict instructions not to meddle with “the set.”PLATE VOLTAGE.For detector purposes a “soft/*valve is mostly used, and such valves are critical to plate voltages. In other words, one will work very well on say, twenty volts, while another will need only about eight volts. It is not a bad scheme to use a multi-point switch in order to get the correct amount of voltage in the plate circuit. It is not absolutely necessary, however, because modern valves are much: more stable in their operation than they used to be.

TELEPHONE: CITY NO. 802.RODMAN & KELAHER,Electro-Medical instrument Makers,f-lOTa EBizabeth Street, Sydney.lONIC MEDICATION OUTFITS. HOT AIR MACHINES. MEDICALBATTERIES. ACCUMULATORS. X-RAY APPARATUS * SPARKCOILS. ELECTRIC STERILIZERS. MAGNETOS.Anglo-American Book Shop.WILLIAMS AND SON(late Hallams).Q.Y. 1 UILDINGS,459 GEORGE STREET,SYDNEY.All the Latest Wireless Books and.Magazines in stock, posted anywhere.Our Radio Yarn.THE DREAM.“Well, mother, anything else 1 can get you?”Fred Ghampion, a sturdy youthof 15, smiled down at his mother, on whose pretty face sickness had put its mark.“No, thank you, Fred. I’m quite comfortable now, so you run away to your beloved wireless, and. I’llthink out a nice welcome for father when he gets home to-morrow. ’Fred strolled down to the little shed in the back garden, where his radio outfit was housed, and sat down before the receiving panel.He had got his love of radio from his father, who was chief wireless officer on a cargo steamer trading between Australia and America.After a couple of months’ absence, the steamer bearing his father was nearing home and was due in port the. following day.Mr. Champion would be surprised to find his wife on a sick

soon be about again. “But she must have no worry and no excitement,” was his warning.“I’ll see if I can pick up Dad, thought Fred, as he put on the ’phones and switched on the valve.He looked at his watch. It was eight o’clock, usually a fairly busy time, but to-night there was very little doing. A large passenger steamer, a long distance away,was talking with the coast station, some 15 miles from Fred’s home, and static bubbled and crackled

Suddenly, Fred started. Dots and dashes were coming in fast, and to his trained cars they formedthemselves into the dreaded 5.0.5., the appeal of those in peril at sea.Fred pencilled the message, and tears were streaming down his face when it ended, for the ship in trouble was his father’s. The message that told the story was:“Struck a submerged object 2 o miles due east of Black Point.Sinking by the head; cannot remain afloat many minutes.”Fred started to rise, but, realising his helplessness, sank back in his chair again. That the vesselwas in a Lad way there was no doubt. Her signals were veryweak, and the young operator surmised that his father was sending on his emergency power.He listened in again. The signals had ceased, and he waited for the coast station to reply. ThenFred got the second blow of that night.The coast station had missed theS.O.S. message, and was asking for a repeat. Several times the request went forth, but there was no answer from the ship. She had either foundered or her emergency batteries had given out.How would the rescuers know where to go? It was improbable that any other station had caught the message, for they would have relayed it on to the coast station ere this.Fred stared at the message on the pad in front of him. Yes! He could telephone it to the station.Snatching off his headgear, he dashed off to the nearest public telephone and gave the message to the officer in charge of the coast station, who happend to be a friend of his father. “Right sonny,” the officer said; “we’ll get to work. Give us a ring in half an hour, and we will tell you what’s doing.”The half an hour went very slowly for Fred. He thought of his sick mother. The news would surely cause a relapse, if not worse.The next news from the station was that a fast destroyer was on her way to the scene. “If you listen in, said the officer, “you Will hear her reporting to us.”Some six hours later the white-faced youth heard the destroyer’s message: —“Searched the vicinity given thoroughly. Plenty of wreckage, including smashed lifeboats. No trace of survivors.”Heavy of heart the lad went into the house and looked into his mother’s room.“Come here, Fred,” whispered the sick woman, “I'm not feeling too well. I had such a dreadful dream, in which I saw Daddy’a ship go down.” Suddenly she started to sob violently. The sobbing ceased as the youthreached the bedside, and he' heard the faint whispef: “I’m going to join Daddy, Fred; good-bye. He died doing his duty.” 1The frail form on the bed was very still, and the orphan pillowed his face in his hands and wept because of his great grief.Referring to the success of the recent amateur Trans-Atlantic tests an American Professor compared the picking up of the feeble signals in Scotland to the perception by eyesight of the rays of anordinary electric bulb at a distance of 3,000 miles.

“STAR” RADIO BATTERIESs at&We manufacture Special Radio Batteries(both “ A” and “ B” type),They are recognised to be better than anyimported battery, and no set is completeand up-to-date without a “ STAR” Spare Plates or Parts Supplied to amateurs desirous of making up theirown batteries.Full particulars and prices on application.Batteries repaired, re-charged, and hired-out at lowest rates.STAR BATTERIES LIMITEDStorage Battery Manufacturers“Hitch your Radio to a STAR.”_ 43-45 Wentworth Avenue,(Next Australian General Electric Company),Sydney.THE BUSY PEN.Mr. Allen Burrows writes:A central organisation as is at present being formed, consisting of representatives from amateurand professional wireless bodies, would have important and farreaching effects on the radio community of N.S.W. Never before has the need for such an association been more urgent. Whenthe advantages derived from a similar organisation in America are so manifest, the pity is that it has not been done here before; if it had, conditions would probably be different to what they are now.But to reach its true objective, the association must be absolutely representative; for it to be otherwise would be unjust to those whom it excluded. Dealing withthe authorities as an organisation professing to be representative ofthe amateurs of N.S.W., it wouldreally only represent those whomits conditions favoured. Exactlyw'hat those conditions may be is be-side the point; at present, it ap-pears they will consist of restric-tions confining representation toamateurs or professionals, fortun-ate enought to have the opportun-ity of assembling in certain num-bers. A smaller body of whole-hearted enthusiasts, whom circum-stances prevent growing in num-ber, are accordingly unrepresent-ed through no fault of their own.The contention that they can al-ways join a larger club, therebygiving themselves representation,is as unfair as the restriction itselfis. The small club has as muchright to retain its individualityand to make its voice heard, asthat which has the advantage ofnumbers; or, if not as much right,if has a certain right (proportion-al to its size) which should be re-spected.After all, it is the wireless manhimself that a central organisationis out to help, regardless ofwhether he lives in the city andis able to belong to several largeclubs at once, or whether circum-stances prevent him joining a bodyany larger than the numerous sub-urban clubs which are now inexistence.Dear Sir,I am sure you will be inter- *ested to hear about a little experi- <ence of last week. I had occasionto visit an aged and somewhat in- ,firm couple who live in an isolatedcottage not far from the city, andfound them reading the first issue tof your little paper “The Wireless:Weekly,” and animatedly discus-;sing it.The old lady told me that wire-less had always fascinated her, .and only for the great expense -she would have possessed an out-;fit long ago. I am making her alittle set as a surprise, so that she .may hear the concerts, and amsure it will be a hard task to con-vince her how small the expensesreally is, for one who lives so close jto the city.Wireless is indeed proving agreat blessing and deserves allpublicity it can get.“C.Q."

HETERODYNE.WHAT IT MEANS.The literal translation of theword, is “other power.” _ In itsapplication to radio, the hetero<-dyne effect is used in continuouswave telegraphy—the modernform of signalling by means ofwireless. The theory* df hetero-dyne can perhaps be-' best explain-ed in theTfollowifig manner: Thetransmitting station will be send-ing out waves ofa certain specific frequency, whichfor the purposes of illustration wemay say is. 50*000. cycles per sec-ond.Now this frequency is far toohigh for the human ear to re-spond to, and it is also too highfor the telephone receivers to re-cord. The problem that had tobe solved before continuous wavetelegraphy became a success washow to reduce this frequency sothat the telephones would recordthe signals and make them audi-ble to the ears.MOST EFFICIENT. .. .The heterodyne method hasbeen* found the most efficient, andit consists of pitting one set ofhigh frequencies against another.In our supposititious case the in-coming frequency is at the rate of50,000 cycles per second. In or-der to obtain results in the tele-phones the operator causes his re-ceiving set to oscillate, or, inother words, he turns it into aminature transmitting set. Headjusts these, oscillations untilthey are about 49,500 cycles persecond in frequency.The condition that now existsin his receiving apparatus is this:The two sets of frequencies clashwith each other 500 times everysecond, or to put it into electricalphraseology, they are out of phasewith each other 500 times eachsecond.MUSICAL NOTE.New, every time they clash thetwo sets of frequencies cause aclick in the telephone receiver andclicks running at the rate of 500a second produce a very musicalnote. It will be readily seen thatthe operator, being able to controlthe oscillations of his receivingset, can produce any musical notehe pleases, because all he has todo is to vary his own set to makethe number of clashes per secondanything 1 he chooses. He can, forinstance, make it 100 per secondor 2.000 per second.Another advantage of this sys-tem is that in the event of his be-ing interefered with by ordinaryspark signals he has a good op-portunity to overcome this inter-ference by simply making his ownset produce higher frequenciesthan the incoming wave, and stillget the same results. In otherwords, instead of producingoscillations at a frequency of49,500 cycles a second, he can goto 50,500 cycles a second. —“Popular Science Siftings/’RADIOPHONE.SIMPLE SENDING SET.In view of the fact that trans-mitting will soon be allowed inAustralia, the following article bya writer in the “Wireless Age”should interest. —Many amateurs would like toconstruct small radiophones, butthe numerous instruments thatare used confuse them and theyare afraid to build one for fearit will not work. I have builta set that is the last word in sim-plicity. It is very efficient andwith 60 volts on the plate, willcover 5 miles very easily. I havobeen heard at a distance of 20miles. A circuit diagram of theset is given in figure 1The inductance consists of acardboard tube 2 inches in dia-meter wound with 36 turns ofnumber 16 D.C.C. wire. Thewire should be wound from oneend (A) and at the 19th turn atap off (B). Seventeen moreturns should be wound to make36 turns in all. The variable con-denser in shunt to the inductancehas a capacity of .0005 rnfd. Theplate potential can be composed ofthree ordinary “B” batteries con--nected in scries, but if a fewmore are used, so much the better.The tap (B) is connected to theFig. 1positive side of the filament light-ing battery. A key can be con-nected in this lead as shown inthe diagram for continuous wavetelegraphy. When using the setas a radiophone, this key must beclosed. A microphone of the com-mon land telephone type, whichcan be purchased very cheaply, isconnected in the ground lead. Al-together this set is very simple toconstruct and is reliable andstable in operation.— .Keep an eye on your lead-intube. Damp will cause bad insu-lation and poor signals.

WIREIESS books.Consolidated Radio Call Book. 10s.Design Data for Radio-Trans-mitters and Receivers (by Sleeper),4s 6d.Wireless Marconi Military PackStations. Technical Description,2 s.Handbook for Wireless Operators(Licensed H.M. Postmaster-Gene-ral), 2s. 6d.Wireless Telegraphy and Tele-phony. Fully illustrated, 2s.jThe Maintenance of WirelessTelegraph Apparatus3s 9d.N.S.W. Bookstall Company, Ltd.,476 George Street.Beautiful Illumination withPARIAN WAREHUMPHREYS’ LIMITED,465 George Street, Sydney.Telephone: City 3849.RADIO SETS\and Paris to make them.Send for Price Lists.ELECTRICAL UTILITIES SUPPLY COY.605 GEORGE STREET, SYDNEY.jMUSIC IN THE AIRSUNDAY NIGHT’S CONCERT.Mr. Maclurcan’s concert, for nextSunday night, commencing at 7.30,includes the following Pathe re-cords. If any fading of the highernotes in the vocal records isnoticed, kindly report particularsto Mr. Maclurcan.Fox Trot. —“Sweet Love.”Bed Time Story. —“Three LittlePigs.” (The little ones can thengo to bed.)Hawaiian Guitar. —“La Paloma.”Soprano.—“ll Secreto di Suzanne,”Claudia Muzio.Piano Solo. —“Prelude in C SharpMinor,” Rachmaninoff.Xylophone.—“ The Little Rascal.”8 p.m. Code Practice, C.W. andBuzzer.One Step.—“ Swanee Rose.”Hawaiian Guitar. —“Hawaiian Para-dise.”Banjo.—“Parsiflage.”Baritone. —“Kashmiri Song,” fromthe “Indian Love Lyrics.”Baritone. —“The WTiistling Yarn,”G. H. Snazelle.Recitation. —“The Cricket Club ofRed Nose Flat.”AN APPRECIATION.(By “Listener).Sunday nights are eagerlylooked forward to by radio en-thusiasts, both amateur and pro-fessional, throughout the State ofN.S.W., and we have to thank Mr.Chas. Maclurcan for it.Through his kindly and gener-ous nature he entertains hundredsof people with a very excellentmusical programme, broadcastedfrom his station at Strathfield. AC7.30 p.m. every amateur has hisset tuned to 1400 metres waitingfor the preliminary V’s to tune inon. And what a welcome soundit is after a week of dots anddashes!Everyone breathes a sigh of re-lief if the old set is working O.K.A few preliminary remarks, andthen the concert programmestarts.I think I am right in saying thatMr. Maclurcan is the pioneer ofradio telephone concerts in thiscountry, and the regularity ofthem makes his name a householdword. We cannot express the en-thusiasm and delight the hundredsof amateurs feel over his splendidSunday night concerts.The “Wireless Weekly” alsotakes this opportunity to expressappreciation oh behalf of itsreaders, to Mr. Maclurcan for hisgenerous attitude towards theamateur experimenters. We hopethat he will long continue to giveus these much appreciated Sundayevening radio concerts.FOR THE FARMER’SOUTFITS IN SCHOOLS.In the Legislative Assembly onTuesday night, the Minister forEducation told Mr. Arkins that hewould consider a scheme of install-ing wireless outfits at countryschools, and thus giving the chil-dren a training in wireless tele-graphy and at the same time dis-seminating valuable weather infor-mation to the surrounding farmers.“Hush,” said Dick to his smallneighbour, Joe, who was permittedto watch Dick operate his wonder-ful crystal set, “I hear a ship!”“I suppose” said Joe, in an awe-stricken voice, “you can tell thatit is a ship, by the waves”?

Get it by Wireless:THE RADIO MAGNAVOXBreaks the restraints and restrictionswhich confine the use and enjoymentof Radio to the technical expert andthe man wearing the Head Set.Tha Radio Magnavox:The Re-producer with theMovable Coilgives volume without distortion.With THE RADIO MAGNAVOXwireless entertainment in the homecan be made a source of pleasure andthe centre of attraction for anyfamily or social gathering.Wo Head Sets ar*oNecessary,Inquiries invited on any Radio prob-lem or special apparatus.Call, write, or phone,MAGNAVOX AUSTRALASIA,17 THE BANKING HOUSE.,228 PITT STREET, SYDNEY.Phone City 3710.“Yours for EverythingElectrical,”For the Home, Factory, Workr, Shops, or Ships,We aim to Sell only the Best.Prices are made to Suit all Purses.ELECTRIC IRONS, TOASTERS,FANS, from 305., 475. 6d., 90s.Try a Course of my Cheap50 C.P. Lamps, only 1/3. 13/6 Doz.All Guaranteed and Tested.Round theClubs.THE WAVERLEY AMATEURRADIO CLUB.In view of its intention to instala transmission set suitable for1 .000 metres, is remodelling itsaerial. When completed, it willconsist of three wires on 10 footspreaders, with a length of aboutSO feet. In addition, the aerialis being entirely re-insulated. Thechief difficulty of the Club’s setnow lies in the valves, which haveto be imported. Mr. Maelurcanhas been consulted, with the ob-ject of obtaining his opinion onthe different makes.A separate night has now beene 3lotted for code practice at theClub rooms. This inauguration,n is believed, will materially as-sist members who are engaged inlearning Morse.1LLAWARRA RADIO CLUB.The Ulawarra Radio Club had abusy evening at its last meeting on17 th inst.A le tter to the Club from theController of Wireless was read inreply to enquiries made as tospeed tests and licenses. It wasdecided to make application for apermit to carry on speed tests, andMessrs. Hewett and Gorman wereappointed to conduct the tests.Mr. C. Borthwick then gave aninteresting talk on fundamentalprinciples of wireless. With the as-sistance of Mr. E. G. Bailey hegave a simple demonstration of thetransmission of electric waves bymeans of a spark coil attached toa loop.The Club’s delegates (Messrs.Hewett and Atkinson) then report-ed the result of the recent meet-ing of Club delegates, whereuponsome lively discussion ensued,particularly as to the capitationfee to the proposed Association.The desirability of such an Asso-ciation was generally conceded,and the Club decided to throw inits lot with the Association, pro-vided the. fee was limited to 2/-per member, and subject to otherimportant matters being put on asatisfactory basis at the adjournedmeeting.The next Meeting of the Clubwill be held at the Carlton Schoolof Arts on 31st August, at 8 p.m.Buzzer practice, 7.30 to 8.METRO CLUB!There was a well-attended meet-ing of the Metropolitan RadioClub at the Kardomah Cafe, KingSt., last week, when the President,Mr. R. C. Marsden, occupied thechair. The social side, which isusually such a feature of thisclub’.s meetings, had to be deletedon this occasion, as the time wasmarked out for discussion of thematters arising out of the recentInter-Club Conference.Various views were expressed,the most vigorous discussion cen-treing round the capitation fee forthe proposed wireless council forNew South Wales. The delegates,Mr. Marsden and Mr. Best, wereinstructed not to consent to morethan 1/- per head for each mem-ber.The members of the club wereunanimous in their praise of Mr.Maclurcan’s kindness in sendingout the concerts, and a vote of ap-preciation was carried. Mr. Palm-ar gave a talk on batteries, whichwas much appreciated.

SALE & EXCHANGEThree Lines (approximately,15 Words), may be inserted inthis Column for 9d.Extra Lines or part thereof,at 6d per line.FOR SALE.— Crystal set; L. coupler,detector, Ph. cond. and ’phones. ApplyN. J. Hurll, Northcotc Av., Killara.Phone Jlll3.Has anyone a good 6-volt accumulatorfor sale? Price, etc., A. Pickering,Wigram St., Harris Park.WANTED—A Post Office Resistance Box.C. Maclurcan, St athfield.9 9 9a ■ ■What do you want to know?Every reasonable specific Queryin the field of general wireless ad-dressed to the Information Depart-ment will receive a prompt reply.While lengthy replies cannot begiven to complicated questions in-volving extensive research or com-putations, this department aims toj© of maximum ..ervice in supply-ing information as to what booksor other sources may containanswers to these questions.A stamped addressed envelopemust accompany each question, butthe writer’s name will not be pub-lished if he so requests.Address the Information Editor,‘Wireless Weekly,” Box 378, G.P.0.,Sydney.STATION CALLS.SHIPS STATIONS. GREATBRITAIN.Backworth, GCBZ; Badenia, GB-ZD; Badagry, YEC; Bahadur; XTK;Bahia Castillo, GBSC; Baldina,XXE; Balderton, GDQC; Ballarat,GFBL; Balfe, GCQB; Ballena, GC-YF; Ballycotton, GFLW; Balmoral,GFQP; Ballygally Head, GBRK;Balranald, GFBM; Balmoral Castle,MPW; Baltabor, GDLB; Baltamar,GDXK; Baltannic, GDWM.Baltic, MBC; Baltriger, GDXC;Baluchistan, LXK; Balzac, GC-SZ; Bamora, MST; Bampton, LSQ;Bampton Castle, YBF; Banca,MFS; Banchory, ZQS; Bandon,GDVL; Bandra, MCH; Banffshire,GVM; Bangala, GAC; Bankdaic,ENF; Bankura, GCH; Baradine,GFBN; Barala, GCM; Barbadian,GBQM: Bardic, BEM; Barima,ZNB; Barjora, GCT; Barlby, BTT;Barmoor, EZL; Baroda, GDL;Ilaron Ailsa, XES.Baron Ardrossan MWW; Bar-on Berwick MSS; Baron BlantyreXLN;, Baron Cathcart ZRI; Bar-on Cawdor GBTZ; Baron DouglasODD;,Baron Elcho ZPP; Baron-esa ZQA; Baron Fairlie LUZ;Baron Garioch GBNC; Baron Inch-cape BAU; Baron Jedburgh MGD;Baron Kelvin EOT; Baron MintoYEK; Baron Napier MJS; BaronPolwarth BRB; Baron RenfrewZOQ; Baron Sempill ZFP; Bar-otse ZPR; Barpeta MPR; BassaYYJ.Barrabool GFBP; Barranca MLL;Bassan ZMJ; Barrymore GBDT;Bassano YQA; Balta GBST; Bat-anga YEB; Bathurst GBMP; Bats-ford ZXL; Bavarian ZTU; BayanoGMK; Bayford BEL; BaychimoGDWK; Bay cross ZYZ; BaygolaZXW; Baydouglas ETU; Baygow-an ZVY; Baylula BAF; BayhowellATW; Baymano YHX; Bayman-ter BAD; Baymingo YHP; Bayra-mento YCW; Baysarnia YNW;Baysarua EQO; Baytigern ESP;Bawerdun ZXX; Beacon GrangeGCQL; Belgic ZXC; BearwoodGFCD; Bearerton XTO; Becken-ham EWU; Beechleaf EZG;Beechpark GCBR; BeechwoodYAE.Belgian GCNM; BelgravianOEK; Belize BEO; BellerbyESY; Bellerophon GTD; BellfieldYDZ; Bellglade BKR; BelltownZCD; Beltana MKR; BembridgeYKX; Bempton GDMB; BenalderENS; Bcnalla GBJ; Benarty YLT;Benavon EJD; Benclench ZZA;Bendigo GFBQ; Bendoran YEM;Bendu ZME; Benedict ZKY; Bene-factor MOE; Bengloe YVA; Ben-guela ZMQ; Benin ZMR; Ben-ia wers YJS; Benledi YLU.Benlomond LTC; BenmohrBDO; Ben Nevis GYX; BenrinnesEKC; Benne ZMFj BenvenpeEPQ; Benwood YCA; Ben VoilichGCFB; Berbice GIF; BerebyYDC; Berkut GBTR; BermudaGBUJ; Bernini XFE; BerriedaleLUI; Berrima YWR; Berwick-shire YZS; Berwindvale GCQX;Betwa BUZ; Bliamo GWAJ Bhara-ta GAD; Biela YNC; Biafra YGF;Biarritz EZN; Bisley YCB; Dide-ford BOA; Bilbster BUC; BinficldGBMV; Bithina YJX; BitternGBXQ; Blackheath EWW; Black-hill BCC; Black Prince YJB;Black Sea GDLW; BlackwellZLC; Blair more BOB; BogotayAC; Bloemfontein GBN; Bod-nant YQO; Bohemian MEL; Bo-kana YCQ; Bolingbroke BGE;Bolivian GCNB; Bolton AbbeyGBRV; Bolton Castle MAQ; BomaGBSV; Bompata GFCV; BonheurGCTS; Bonny XIN; Borda MFQ;Borde GFMR; Borderer GCL;Borderland MUM; Borelis GCWM;Borodino ODT; Borulus GFJN;Boscombe Chine XEG; BosnianOEL.Boston City GDSB; BoswellBMK; Bourkadra YGB; BoulamaYMJ; Bourne GBCS; Bourne-mouth ZJD; Boutry YCZ;BovericYNY; Bovic GDO; Boverton XHK;Boyne ZUY; Bremen GBJK; Bra-bandier EUM; Bradavon XLG;Bradburn ETY; Bradclyde YRB;Bradford City GBCL; BraunfelsBPG; Braemar Castle GCQZ;Bray wood GDTK; BrambleleafZZQ; Brant County GBYT; Brand-enberg GBSF; Bratton CastleYAN; Branksome Hall GBFQ;Brazilier OET; Breconian YEW;Brenden BEK.Brescia ESS; Breslan GFCN;Brier GDYL; Bretanier EXP;Bretwalder GBJR; BreyntonLSZ; BriaCrleaf EYA; BriarwoodZGD; Brighton BNF; BrightonMOV; Bristol City GDML; Brit-annia GCRB; Britannia GAP;British Admiral ZYY; BritishBaron EYU; British Beacon BOU;British Birch EYD; British CoastGDTC; British Colonel GFDB;British Duke EYY; British EarlEYS; British Emperor ZLK; Brit-ish Empress ZYZ.British Ensign ZYV; BritishFern EZE; British Holly EZL;British Isles ZYW; British KnightEYN- British Lantern BON; Brit-ish Light BOD; British MajorBLN; British Maple EYB; BritishMarquis EYW; British MarshallYJJ; British Peer EYM; BritishPrincess ZYT; British Rose EQC;British Sailor OFK;- British- Sol-dier YQR; British Sovereign ZYU;British Star BOI; British TommyGFQL; British Transport ZDT;British Vine EPK; British Vis-count GFDY; Briton MQJ;Broadmayne EXX; BrocktownGCXJ; Bronte GCPZ; Broads-worth ESE; Brookvale BRB.