i/ FULL-SIZE BLUEPRINT FREE INSIDE

NO 787-VOLJOUC FEB13TP 1937 REGISTERED AT THE E.PII A5 A NEWSPAPER

PRESENTS HIS

,Likamentitis.-AmifidNidi; 11 POPULAR WIRELESS February 13th, E37 An Event for all who Enjoy Thrill Stories Ti II C: WEIAREGD. TRADE MART( COMPONENTS Specified for JOHN SCOTT-TAGGART'S GREAT CORONATION SET The "SUPER CENTURION"

TRIPLE EXTRACTOR COIL UNIT tionof Complete as shown PRICE 716 by LESLIE CHARTERIS or the COMPLETE EXTRACTOR- UNIT

In five continents and on seven seas the Saint is Complete to original specification, the recognised king of modern buccaneers.In The mounted in attrac- 14' Return of theSaint,' The THRILLER publishes tive case. PRICE his latest escapade.Here is a powerful long novel, telling how an earnest young man, who stole £7,000 to pay a £10 debt, came within a stone's -throw ofthe scaffold, and H.F.CHOKE how the Saintsnatched him from the 8 o'clock walk TYPE H.F.J.

. . . . telling of a forger who did a neat job of penmanship H .F . J. Totally Screened. ten days after he was shot at dawn ... of one who dangled Range 100 to 2,000 metres. £40,000 under the Saintly nose, and was astonished when Self capacity 7 mmf. Induc- he losthis money . . . .of Detective -Inspector Teal who tance220,000mh. D.C. tugged the beard of an innocent old man, thinking he Resistance 770 ohms approx. was the Saint indisguise.In fact-one of those joyous, devil-may-care adventures for which theSaint is world-famous.Meet him today ! PRICE

ai Send for New Wearite Fully Illustrated Catalogue, gljD w and new black print of S.W. Battery Receiver. WRIGHT & WEAIRE LTD. 740, HIGH ROAD, TOTTENHAM, N.17 111111ILLE Telephone Tonenl,orn 3.547 :8, 9. On Sale at all Newsagents Every Saturday 873 Popular Wireless, February 13th, 1937. Z89

EditorG. V. Dowding. Asst. Editors :A. Johnson -Randall, A.S.Clark.

ARABIAN NIGHTS BAND OF HOPE NIGG-LI NG RADIO NOTES & NEWS O.K. FOR SOUND WELSH CRY U.S.A.'s FLOODS

The First Wireless Prophecy three hundred " P.W.'s " and a few other rejoiced exceedingly atthiscrypticre- WHAT'Sall this about wireless being wireless books. I should be pleased to joinder,for they knew what "Nigg " " prophesied in1700 and some- pbst them in lots -,-no particular order- meant. It is the name of a place just thing ? " asks W. T. L, of the to anyone (or ones) who cares to send me outside Aberdeen, where there is a fine site C.T.O., on reading my recent Note about the postage for them. (Parcel rate would not for a 5 -kilowatt station, soon to be erected. the first wireless prophecy. cost much.) It seems a pity to waste them." Five kilowatts for Nigg are better than one " John Baptista Porta," he says, " de- BUT-there is one snag !Every free niggling kilowatt in Aberdeen. scribed a ' sympathetic ' telegraph in 1558. copy of " P.W." will be found to have In 1665 Joseph Glanvil foretold communi- its " W. L. S.'s " page-or two pages- Third Network for U.S.A. cationby meansofa' sympathetic ' neatly removed ! And nothing you can say you know, the broadcasting system telegraph.' will persuade Mr. Raithby to part with ASof the U.S.A. is not a Government Moreover,hecontinues :" Re your them !It seems to me that all unwittingly controlled monopoly like ours, but correspondent'sreferencetoaBiblical this has turned itself into a pretty corn - isaprofit -making competitive business, quotation, Porta's idea was to use paid for by radio advertising. the Lodestone (natural magnet) Until recently there were two and twoneedles. Well,the WITHOUTHIS BLACK -FACE MAKE-UP big coast -to -coast networks, be- Chinese were acquainted with longing to the National Broad- the stone's properties some 2,500 castingCorporationandto years B.c., and they actually used Columbia Broadcasting System it at sea about A.D. 300.Wha' respectively.Now the Mutual 'ja know about that ? " Broadcasting System has acquired To which I rejoin that the the Don Lee Network of California wily Orientals are credited with as well as the Iowa and Central having used the lodestone for a States network, thus making a navigational magnet, but never, third big system extending from so far as I can learn, for any the Atlantic to the Pacific. kind of wireless.So what ? The Mutual folksare very pleased at having acquired equal Arabian Nights status with Columbia and Nat- SPECIALbroadcast pro- ional.This pleasure, however, grammes and news directed is not mutual ! to Arabs in Syria, Palestine and Iraq are to be included in Cry From a Welsh Heart theforthcomingtransmissions JUST a postcard, received not from the Turkish radio stations. long agoatthe B.B.C.'s Other interests, say the Turks, Cardiff station : have been misrepresenting the " Will you kindly give us some- Turkish point of view to these NOSMO KING, the well-known radio artist, with his Cossor set.The name thing lively in music as we are Arabs, and the new policy is Nos mo King was derived from the words " No Smoking " seen in an hotel lobby. melancholy enough now without intended as a counterblast. your chambersmusic in four Few of us had supposed thatradio pliment to my colleague " On the Short movements, etc., violin and piano, etc. Give receivers were among the camp impedimenta Waves."It is a true believer who will us some brass, and also not so much of news. which are nightly folded up by the Arabs literally " take a leaf out of his book " I am paying you to liven me up a bit, not when they silently steal away.But that every week ! to kill me in slow motion.If you keep on great benefit will be derived from the new * * * the stuff as you giving us this last few schemeisconfidentlyaverredbythe Nigg-ling days between the crisesof the country Turkish ruler, President Ataturk. CITIZENS of Aberdeen were not alto- you will be issuing coffins with that duff you Atta Boy, say I.Mustapha go, anyway. gether enthusiastic about the transfer broadcasting now andifyou do send to the new Burghead station of the anything good you comments when it is on Filleted Felicity radio supremacy of the north, hitherto and enjoyingyourselves and nottho WRITING from" Hollis,"Pointon, held by Aberdeen. So they asked the listeners for the love of mike give some pep Sleaford, Lines., Mr. C. B. Raithby, B.B.C. what about a few more kilowatts into it . . . who is known on the air as G 8 G 1, for the city of Aberdeen. This proves that it's not essential to makes a sporting offer. The B.B.C., not in any niggling mood, punctuate in order to discriminate! He says :" I have for disposal two or said" Nigg." And theAberdonians (Please turn to page 610.) THE SUPER CENTURION -OVERLEAF 500 Popular Wireless, February 13th, 1937.

MY CORONATIONSET

HE question: "How many valves should a set have ? " is as old as broadcasting itself. This may be a useful opportunity for considering the pros and cons of the various types of THE SUPER receivers. The Super Centurion has three valves, while the S.T.800 hasfour. Why REMEMBER THE TERRIFIC SUCCESS OF should there be a difference in the two sets ? The obvious THE FIRST CENTURION? WELL, HERE reply is that they are intended to eater for different IS AN ENTIRELY NEW VERSION, JUST publics, and different performances.But tin detailed AS ECONOMICAL AND EASY TO BUILD reply is by no means as simple as all this, and in any case AND USE, BUT EVEN MORE WONDERFUL no one wants to feel that he is getting poorer results INITS PERFORMANCE because he is paying less.Unless the receiver were frankly a local station set, and this were made very clear at the time, I should not offer a receiver with poor per- sive. A receiver designed to give superlative quality on the formance as regards foreign stations merely because there main stations and where very large volume is desired is was a public which did not want to pay the full price of a almost essentially a special job.On the other hand, a

good set. receiver for the reception of short waves is a more It is an old saying that you pay for what you get, and highly specialised piece of work.Sets which will receive this no doubt applies to a very large number of products, only the medium and the long waves and sets which are but I am not at all sure that price is a reliable criterion so-called all -wave models involve considerable differences of a wirelessreceiver. We all have our suspicions, in design and, given a certain amount of money to spend, sometimes, that some of the low-priced commercial sets a better set could be produced for simply the two wave- are just as good as the bands. same firm's more ex- There are one or pensivemodelsand two firms who go in that the extra price is for particularly high- calculated to rope in gradequality, and snobbish people who think nothingof feelthat they must sticking on another have the best at liter- twenty poundsfor allyallcosts. Of this feature. course, there may be a few modificationsal Special Features regardsthecabinet Thehomecon- and insignificantdr. structor is a much tails,butfrequently more shrewd person. the same circuit and He knows what to perhaps eventhe look for even if he same chassis is incor- doesn't know quite porated. what he wants.If Ileave out audio Choosing a Set reaction on the The designer's atti- S.T.800-afeature tude towards his pro- which was so praised spective set is governed and starred in the by therequirements S.T.700-he wants of the public for which 1937's GREATEST SET-to know why.If heiscatering. The tythe introduction ofaerial reaction, enormous amplification is achieved without high -frequency re- lazy thinker may the expense of an extra valve. actionisused on imagine that price con- two circuits in the siderations are almost entirely the only ones in radio S.T.600 but not in the S.T.700 or S.T.800 he again wants receiver design.As regards the majority of commercial to know why. What about reaction equalisation-which sets, I think price is almost entirely the governing factor ; was a feature of the S.T.400-although I honestly do not veryfewpeople who buy aready-made wireless believe that anyone got it to work. The fact that if it set know anything about its features.They buy on didn't work the set could still give good results, is perhaps the strength of the name, the publicity (which is often the best argument in favour of leaving it off in later sets, the same thing), and the price.A higher priced set although I still think that it is a valuable feature. must, they think, be a better set.All thisis rather Here we have to considerthe differencebetween deplorable.I should like to see people buying ready- essential features and those which add to the conveni- made wireless sets for special purposes, as no set can ence of operation or are in the form of luxury additions. provide all the best features unless it is really expen- Now, obviously, if I sat down and planned to give you eaenaememememeememeeemeaemeamemeeemeeematmeemeamemotamemeameameamea i A TRIUMPH OF ECONOMY AND SIMPLICITY !

eaeocaeappecageeeemeappeemeememeameameeeemeemeamenaemeemeaeaexameaeameampam Popular Wireless, February13th, 1937. 591

4JOHNSCOTT-TAGGART

Frankly, as regards the main set of the year, I try to please as many people as possible.Some readers have asked me why, if I used Class B output on the S.T.500, CENTURION did I not employ it on all subsequent sets. Well, here again the reply is simply that Class B adds to the number of IT HAS DOUBLE REACTION GIVINGIT valves required, gives unnecessarily loud volume for the EXTREMELY HIGH SENSITIVITY AND UNI- average listener, and in general is not worth the expense. PLANE CONSTRUCTION AND AN EASY - There are three main classes of receiver.Those that CABINET, AND AN AUTO - DIAL-THE concern themselves with selectivity, those with sensitivity, BIGGEST AND BEST DIAL EVER and those with output volume. The first question I INVENTED have to ask myself is what am I to give constructors in each department ?Only in one set, the Super -Gram De Luxe, did I go " full out " under all these headings-and what I thought was the set de luxe, you would have a the cost was somewhere around £75.It is, of course, no score of gadgets.Each would add to the price and some use asking the public what it wants. The answer always would add to the perplexity of operation.There are is " everything.'This highly intelligent reply puts de- seven knobs on the average television set and they signers on their mettle.They know they cannot give areallnecessary. The squealers about everything to thefull, but they complexity of operation have simply got to have a very good try.But the lump the seven adjustments, whether they best solution is not to give as nava like them or not.I experience a certain as you can afford under each of amount of malicious glee at the thought of these headings, because requirements the ignorant general public having to twiddle are so different, even though the seven knobs instead of one, but at the same individual isinclined to ask for time there is in all these matters a sensible everything. mean. The Question of Volume Simplifying Construction A large section of the public likes Although I have made no attempt to to have very loud signals. I do for produce a set having one knob intended one, provided the quality is as near for construction on a largescale,yet I perfect as doesn't matter. But such have definitely moved in the direction of a high grade of quality costs a lot of simpler construction and without sacrificing money to produce, and so we are performance.It is always a very astonishing concerned, especially in battery sets, thing to me that perhaps the most opular to give good quality at a much of all my _sets - the S.T.400- lowervolume. Amongst the was (or rather is, because there noise merchants, we have those are huge numbers stillgiving who want a great output and good service) the most difficult want it not only on the local of all my sets to operate. stations, but on practically every The fact that there must be a other station aswell. Now limit to the adjustments on a that really does cost a lot of set prevents the designing of the money if it is to be done well, ideal receiver.My own idea of and is outside the scope of the the best simple straight set with average constructor's ability and luxury attachments would be pocket.Another more reason- the S.T.600 circuit with a triple able section of the public likes extractor, audioreactionand -BRITAIN'S LEADING DESIGNER John Scott -Taggart, F.Inst. P., KAm.I.E.E. to have the local station loud, reaction equalisation. And how Fel.I.R.E. specially for brass bands and many people do you think would symphony concerts, for example, build it ? About a dozen. People's tastes are compara- butisquite content to receive foreign stationsat tively simple in these matters, and just as a royal guest moderate volume.This calls for a very much simpler ata banquet may consume twelve courses without set, because sensitivity is not nearly so great.It may batting an eyelid, although he would really much prefer take two stages of push-pull amplification to give good steak and chips, so the average constructor is willing to quality, and this involves four valves. How many con- sacrifice certain features.What feature does the average structors are willing to pay for the extra valves and listener regard as superfluous and tending to complicate components when a single output valve will give them all the construction and operation of a set ?No one can Say, they want ?That therefore brings us to the third class because each man has different ideas.The result is that of listener, the man who does not want a large output, one year I will try to appeal to one class and another either on a foreigner or the home station. He is content year to another. with good room -strength signals which will not cause the eameameagemeaeaemeaaameeemeaeameeemeaeameenameemeammeaexameemeame IA MIRACLE OF EASE AND EFFECTIVENESS enameamemeameempagAmpagameammarapmeeemeampameamerameaparimInmaaae3eameagioneeme 592 Popular Wireless, February 13th,1937.

neighbours to knock on his wall. But he likes the quality obtained.There is a very sensible body of listeners who of reproduction to be good, and since he is content with argue that very weak stations are not really worth listening a low output volume, this can be given to him at low to anyway, but that the main foreign stations which come cost.Nearly all sets distort due to over -loading, and there- in at good strength should certainly be received clear of forethe man with modest ideasof output strength interference.It is therefore hardly fair to judge a set enjoys better quality of reproduction. by its performance under the most difficult conditions of The question of sensitivity is not such an easy one to reception.It is better to decide whether it performs the decide.The constructor rightly feels that his set should duties which its constructor asks of it. be Sensitive because if it is not so, he will be unable to receive many foreign stations at the same output as his local.At first thought one might imagine, since the local isso much stronger than any foreign station in the case of those who live fairly near to the B.B.C., that the B.B.C. should always be very loud and the foreigner never able to compete.This is utterly erroneous. On a good set scores of foreign stations will load up the last valve of yoursetand so give excellent signals.The local stationcannotdo more because if it did it would be distorted.Therefore, though the local signal may be very much stronger in the aerial, it has no advantages overanyforeignstationsas regards loudness.This only holds goodif you have a sensitive receiverorratherasensitive receiver -cum -aerial.If you have an insignificant size of aerial, say six inches of wire,your local station may certainly be louder Programmes from every part of Europe can be than a foreigner, but if you have tuned in with ease on the Super Centurion. a fairly good outside aerial the chances are that on quite a medium -sensitivity set a If we agree that a medium output of good quality is large number of foreign stations will give you all that the satisfactory, we can do surprising things with only three set can handle as regards loudness.If you want still simple valves. Obviously four valves will be more louder signals, you have to go in for a bigger output sensitive than three, provided the same systemsof valve, at the same time increasing no doubt the size of reception are employed.Where only very small indoor the aerial or the sensitivity of the set by the addition of, aerials can be arranged, four valves are obviously desirable. say, an extra stage of low -frequency or high -frequency But where a reasonable aerial can be put up, a good three - amplification. valve set can perform prodigies of *sensitivity.Every year brings the No Compromise Possible FOUR STAR FEATURES three -valve set more into its own. As regardsselectivity, no com- There have been annual increases in promise is really possible here. There 1. AMAZINGLY SIMPLE CON- power of a large proportion of the broadcasting stations of Europe and are probably only two grades of STRUCTION GIVEN BY THE selectivity, namely, good and excep- thishas made sensitivity a, less tional. No one wants less than good UNI-PLANE SYSTEM important ingredient in a receiver. selectivity, even if the set is given Here the three -valve man greatly away with a pound of tea.This 2. CHEAP TO BUILD, COUPLED scores.This increase in power has greatly lessened the need for four did not used to be the case.-The WITH VERY LOW RUNNING astonishing number of very simple valves ; where a couple of years ago det. and two L.F. receivers bears COSTS I should have hesitated to recommend witnesstothe lowstandard of a three -valve set at all, I can now do selectivity which once satisfied the 3. ADJUSTABLE SELECTIVITY so wholeheartedly knowing that a large number ofstationscan be listening public.But I should like CONTROLLED BY SWITCH to say here that good selectivity does received.On the Super Centurion it is possible to get excellent results not mean good under allcircum- 4. AERIAL REACTION, SAVING stances.The real test of selectivity on a hundred stations, which is the is where one station is coming in very COST OF EXTRA VALVE reason for the name " Centurion." loudly while the desired station is con- This assumes an outdoor aerial siderably weaker. If the position* of average proportions.Half this is reversed, selectivity may become extremely good. Good number can be reoeived on very poor aerials, while a selectivity may therefore mean that you get exceptionally score at the very least should be capable of being good selectivity on the main stations, British and foreign, received with only a couple of feet of wire as aerial.This and rather poor selectivity where a weak foreign station astonishingsensitivityisattributableto the use of is to be received in the face of a very powerful neighbour. " double reaction," a system to which I am enthusiastically The selectivity may be called " good," but in one direction committed. The difficulty of incorporating the short this may flatter, the set, while in the other direction it waves on the S.T.800 is the only reason why this system was does not do justice to the excellent results that may be omitted on that ret, although, of course, double reaction eacameemeemememememeaemeammeagmeeerameemeeemeaemeaeaeomemeameeo SUPER CENTURION -THE SET ocageagmeameeeeeeeemeemeaemememeameemeameemememeemeaememeamememeamemo Popular Wireless, February 13th, 1937. 593 is not so spectacular in the case of a receiver which has But in the S.T.800 there is more low -frequency amplifica- four valves, as in the case of one which has only three tion.There is, however, not the full advantage of an valves. extra valve in the case of the S.T.800 beca% ie the output The Super Centurion is a truly remarkable combination valve is less sensitive than thatin the Super Centurion. We for only three valves, and there are three reasons.One can therefore regard the Super Centurion as really a three - is the extremely sensitive detector valve, the other is and -a -quarter valve set.For very weak signls it may the sensitive output valve, and the third, and easily the even exceed the S.T.800 in sensitivity, but actual measure- most important, is the reaction applied to the aerial ments under these conditions of double reaction are difficult to take. The Centurion of last year did, not use aerial reaction but, nevertheless, it would receive a hundred stations on quite a medium outdoor aerial.I was astonished myself at itsperformance, which greatlypleasedtheconstructing public.The success of the Centurion last year was not, of course, equal to that of the S.T.700 or S.T.800 but it came a very good second., This year there are added reasons why the Super Centurionshouldprovea great success.It may not have the spectacular appeal of the S.T.800, but to the man who makes more moderate demandsasregardsoutput volume, I think that the Super Centurion is(provided oneis prepared to do without the short waves) a better proposition than the S.T.800.The running costs are much lower if you use high- tension batteries, because the output valvetakes much lesscurrent, No constructional skillis needed to make a success of the Superalthough, of course, four -valve sets Centurion.The simplicity of the Uni-plane system, andcan be run very economically if the provision of a full-size blueprint and a rapid construction guide,you increase the negative bias; eliminate any possibility of trouble. but then, you cannot have the full circuit,as well as the anode circuit of the receiver. output volume that you will sometimes want. The output valve is of the small power type, which will Those who are content always to receive signals at good give very pleasing room -strength of signals.In return room strength-that is to say, loud but not deafening- for the choice of this valve you get a more sensitive output will find in the Super Centurion a set that will run for stage than if you used the larger valves such as have been months without costing much in the way of upkeep. used in the S.T.400, S.T.600, S.T.700 and S.T.800.In In fact, a single high-tension battery of the 120 -volt type these four sets the output stage is not seriously treated will last months and, moreover, you can use the five- or from the sensitivity point of view, six -shillingtype, which would not but more with a view to handling a be recommended fortheS.T.800, large output which the great overall MORE STAR FEATURES for example. sensitivity of the set can produce on nearly all stations. 5. COMPLETE FREEDOM FROM Ideal for the Novice MEDIUM -WAVE BREAK- As regards selectivity I think that Enormous Amplification THROUGH ON LONG the Super Centurion is on the whole The Super Centurion should use the better than the S.T.800, due to the valves specified.The second valve is WAVES use of aerial reaction.When there certainly the most important, while 6. DOUBLE REACTION, GIVING is severe swamping, however, from the small power output valve will the B.B.C., a Triple Extractor is an give louder results on weaker signals UNUSUALLY HIGH SENSI- infallible cure right up to a distance than a bigger valve, but will not TIVITY of one mile from the B.B.C. medium - give quite such a large output volume wave station and about ten miles on very strong signals.The aerial 7. SPECIAL INEXPENSIVE EASY - from Droitwich, or possibly less. reaction system provides an enormous CABINET An indication of my own enthu- amplification at the expense of no 8. POSITIVE STATION IDENTIFI- siasm to this receiver may be gauged extra valve.The full value of this by the fact that I have provided a aerialreactionwillbe explained CATION, PROVIDED BY rapid construction guide which will later, but from your own experience AUTO -DIAL enableacomplete noviceto go of ordinary reaction you will know straight ahead and build the set how greatly signals may be increased* with the aid of the blue print given in strength by this system.Multiple reaction was intro- with this issue.The editorial presentation of the Super duced by myself round about 1923, but the use of H.F. Centurion is not as spectacular and flamboyant as in the pentodes has certainly greatly extendeditsfieldof case of the main annual set, but this need not deter you. application. The Super Centurion is emphatically far and away the The high -frequency amplification side of the Super best three -valve set I have ever designed and, except for Centurion is better than that of the S.T.800 since reaction the factthat the output volumeisalittlebut not is used twice, and therefore, stronger signalswill be much less, the performance of this receiver is well above applied to the detector than in the case of the S.T.800. the average of my last few annual numbered sets. ezieeeemeeeeeeeeeeeemaemeaeaemeeemeeeameatmeemeeeeeaeameameameemeee THAT RECEIVES 100 STATIONS caemememeameememeameameemeameameeeememeemeaeaemeemeaemeeemeamememeaeameemea 594 Pcpular Wireless, February13th, 1937. 0000000000000000000000000000000000000000300peepameemememeemac

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V 0 L 7-14 The theoretical arrangement of John Scott-Taggart's Coronation Set.Remarkable sensitivity is given by the Double -Reaction scheme, the use of aerial reaction saving the cost of an extra valve.Below are the details of the two sides of the Easy -Cabinet.These two pieces of wood, together with the top (see page 598), form an inexpensive and attractive design. ea LEFT SIDE - PIECE R/GHTSIDE -PIECE (Foe WAVE -CHANGE fwa-cw SIDE)

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As regards simplicity of construction, the Uni-plane aerial reaction winding has been provided. The calibration system which I. have introduced makes it possible to put of the coil is similar to that of the S.T.700, so the S.T.700 all the components on one sheet of wood, while the Easy - celluloid dial may be used with it.There are one or two Cabinet system gives you nearly everything that anstations which have changed position or altered their ordinary cabinet does at a cost of 3s.'., as against names, but otherwise the celluloid dial would be quite nearly £1 for a cabinet which is really quite unnecessary in order to use. The paper dial in the middle pages of this and not recommended. Any constructor who buys the issue of POPULAR,WIRELESSmay be affixed to the front Easy -Cabinet and also a normal cabinet is certainly of the panel, either as it stands or, preferably, pasted on 'duplicating matters and spending money unnecessarily. cardboard. Extra copies may be obtained by the simple The set as it stands is a handsome job, and I certainly process of buying extra copies of POPULAR WIRELESS. do not advise spending money on more conventional The calibration of the receiverischild's play and cabinets. extremely accurate.The system has been used on the The price of the Super Centurion is very low, and it S.T.700 and the S.T.800, and consists in having " dot must be remembered that the valves used-certainly the lines " for both medium and long waves.When you identify a station, you simply put a dot under the long pointer where the pointer crosses the line, and this dot KEEP STRICTLY TO THESE PARTS is then joined to the end of the station name. The inner dot line is for putting Component Make used by Designer dots which are subsequently connected to the names of the long -wave stations. 1 Coil Unit . Colvern-specify for"Super Centurion." The operation of the setis again 1 Main Tuning Condenser, 0005 mfd. J.B.-as for S.T.800, but with very simple.There is an aerial coupler S.T.700 knob and pointer. 1 Aerial Balancer Condenser, 0005 mid.J.B.-as for S.T.800 but with which governs theselectivity of the small knob. first of the two tuned circuits.The 1 0005-mfd. solid dielectric Variable Con-GrahamFarish Litloo selectivityofthistunedcircuitis denser (Vol. control).. . . mid -line as used in S.T.800. 1 .0005-mfd. Anode Reaction Condense. - GrahamFarishLitlos log - governed by the aerial coupler which, if mid -line as used in S.T.800. turnedtotheleft(anti -clockwise), 1 0005-mfd. Aerial Reaction Condenser GrahamFarishLitloslog - mid -line as used in S.T.800. weakens signals but improves selectivity 1 On/Off and Change -over Switch .. Graham Farish Turret (with on thatcircuit.This aerial coupler flangednut as used in is also used as a volume control.It is an S.T.800). 1 Anode Reaction Choke Wearite type HFJ. old but extremely important rule that 1 Aerial Reaction Choke Lissen type LN 5092. you should never apply reaction to a 1 00005-mfd. Grid Condenser Lissen mica. 1 -0003-mfd. By -Pass Condenser Lissen mica. signal which is already strong because 1 1-mfd. Condenser T.C.C. type 50. you will' not improve selectivity, and 1 1-meg. Grid Leak .. Erie 1 -watt. 1 L.F. Transformer .. B.T.S. Midget. you will only getdistortion.When 3 4 -pin Valveholders Benjamin ' ClearerTone " requiringmaximumselectivityyou (or " Vibrolder.") should have the aerial coupler turned 6 Terminals (" A," " E,"" H.T.+1," " H.T.+2," " L.S.-," " L.T.+ ") Belling -Lee type R. as far left as possible, so that signals 1 Panel (plywood) 16 in. x 12 in. x 7 mm.Peto-Scott. are weak, and, when the normal anode 1 Easy -Cabinet, with G.B. battery spar.Peto-Scott. 2 Aluminium Brackets .. Peto-Scott. reaction and theaerial reaction are 1 Ebonite Terminal Strip 6 in. x 11 in...Peto-Scott. applied, full but not unnecessarily large 3 Wander Plugs (" Grid+," " Grid -1," loudspeaker signals are obtained. " Grid -2 ") Belling -Lee Midget 1019. " Maxamp " Wire, Screws, Flex, etc. ..Peto-Scott. Tuning -In the Stations VALVES. V1, Hivac VP 215.V2, Cossor 210RC.V3, Cossor 220 PA. A separate article on operation will be COMPONENTS FOR THE TRIPLE EXTRACTOR. given next week, but it may be stated here that there are two tuning -controls, 1 Triple Extractor Iron -core Coil Wearite. 3 0005-mfd. Air Variable Condensers Polar No. 4 with knob (men- one with the long pointer, which is the tion S.T.800). J.B. " Popu- main tuning control, and the aerial lar Log " (without dial or balancer, which is a variable condenser slow motion, but with small knob).Ormond R.483 (log which tunes the aerialcircuit. The condenser) with small knob. method of operation, once you have 1 Wooden Box -5 wood pieces Peto-Scott. picked up a station and logged it by 2 Terminals, Al, A2 . Belling -Leetypo R. Clix Bulgin. placing a dot on the dot line,is to For constructional details of the TripleExtractor, readers are referred to turn the main pointer to that dot and " Popular Wireless " dated November 14th, 1936. then, having applied anode reaction, NOTE : Wearite supply the complete Triple Extractor, wired up, for 24/-, turn the aerial balancer knob until the the cost of the individual parts. desiredstationis heard. Itisall * extremely simple, and has proved itself as the best method of getting one -knob last two valves-are very cheap. In addition, there is the simplicity withtwo -knob accuracy of tuning and good low upkeep cost, both as regards accumulator and H.T. selectivity. and the very much greater certainty of good performance. The aerial reaction is truly miraculous in its improve- In this connection experience has shown that the simpler ment of the whole set but, of course, you can use the the set the more certain it is to work well in all cases. knob turned fully to the left so that very little aerial It is certainly our experience that the three -valve set is reaction is applied, and the set then becomes_ quite a almost entirelytrouble -freeas regardsconstruction. normal three -valve receiver of good type.But aerial The coil unit is of excellent make and completely free reaction enables one to use more aerial coupler, and from any break -through on the long waves. Constructors therefore use the set in a more sensitive condition.This in the North of England may therefore build the set is a point very often overlooked. In order to get selectivity with every confidence.Of course, the Triple Extractor on the aerial circuit (even in the case of the S.T.800) will in any set cure all break -through, but a large number you have to reduce the aerial coupler to reduce the of people will not want to use the Triple Extractor, and losses inflicted on the first tuned circuit.In the case of may, in fact, not need it. the Super Centurion, however, the losses are wiped out The coil unit is similar to the S.T.700, except that an (Please turn to page 620.) eeeenaameeemeamemeemeaemeeeemeeeeemeemeeemeemeeerammeamego A RECORD LOW-COST THREE emeemeenameeeemeameameeeenameeeaeaamaemeameemeemeameeemeemeeeememeao ION 5C11177;BART'S CORONATION SET

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1 Popular Wireless, February 13th,1937. 597 THE SUPER 5' RAPID CONSTRUCTION CENTURION GUIDE The Easy Way to Certain Success

Lay blueprint right way round on back of panel. Keep blueprint steady with a weight.Using bradawl, prick through to panel the fixing holes of all the components that go on the back of the panel.If in doubt about any holes, check by laying component over itspicture.Re- move the blueprint.Using blueprint as check for their positions, screw down the following in order given :Super Centurion coil unit with extension piece, fin. No. 4 round -head brass screws being used :three Clearer Tone Valve - holders (get them right way round), using fin. brassscrews and No. 4 round -head brass screws ;two Lissen nuts, these screws mica condensers, using fin. No. 4 round -head going through the brass screws, taking extreme care that the fin, holes in strip. right capacities are put in the right place, as (H)If you wish to stain the side - these condensers look alike from the top ; This photo. pieces and top, do so now.(I used B.T.S. Midget transformer (right way round), showswell Jackson's, of Mitcham, Surrey, Oil Varnish using fin. No. 4 round -head brass screws ; the amazing Stain, colour walnut, size 6 tin.) Wearitescreenedchoke (markedH.F.J. simplicity of although catalogued H.F.P.J.) with its earthing - Ifni -plane con- tag to correct side as shown in blueprint, using struction. fin. No. 4 round -head brass screws ;Lissen BEAR THIS IN MIND I H.F. Choke with fin. No. 4 round -head brass screws;1 mfd. (T.C.C.) condenser, using fin. The method of construction used in the No. 4 round -head brass screws.Fit turret THIS Guide is as detailed as previous ones of Super Centurionisthesimplestitis switch without knob.Fit volume control con- mine, although the set is much simpler to possibletoachieve.Inthe Uni-plane denser without knob.Fit anode reaction con- construct.The absolute novice is told system all components are screwed down denser without knob Fit aerial reaction condenser where to start and what to do, even to the best on to a single straightforward wooden without knob.Fit aerial balancer condenser way of pushing in a pin !If you prefer, YOU panel.The blueprint is therefore a true without knob. Taking care that the whole panel CAN BUILD THE " SUPER CENTURION " picture of the wires and tells you all you will not rest on the spindle of the J.B. main FROM BLUEPRINT ALONE. But tens of need to know. tuning condenser (whose moving vanes should thousands have reported that my Rapid Guides You CAN'T go wrong if you follow the be closed), fit the J.B. condenser (without knob save them time and guarantee success. blueprint andthisRapid Construction and pointer) to panel, putting its hush washer If you have bought a complete kit, including Guide. on the front side of panel under fixing nut, my " Easy -Cabinet," cross out sections C, D, * which should not be too tight. THIS COM- F, J, K. PLETES THE FIXING OF COMPONENTS. (A)Collectand examinerequired com- (J)Cut out, drill and stain the spar (see Fig. Now you are going to wire the components, ponents.Check each itemtoseethatit corresponds to my list of parts actually used. 5), which holds grid -bias battery in place. and for this you need the blueprint. Handle J.B. tuning condensers with care, keep- (K)Lay the panel face downwards on a Lay panel face downwards resting it on two ing moving vanes closed.Bending of vanes cloth -covered table (to avoid scratching veneer). (Continued overleaf.) would affect calibration of station names. (B)Tighten terminalsecuring nuts (not rEavr WEB/OrPANEL terminal heads) on components where neces- 7mm .414496LX sary. /6 (C)Using Fig.I mark out onthefront (not back) of panel the positions of the holes. fr2- With a fine -pointed bradawl prick all the hole ftir positions.Using a fin. twist -drill, start each i 4°14, fin. hole carefully, using light pressure arid turning thedrillin a reverse directionat first :thisis to avoid splitting the veneer. ye:LA Continue drilling these fin. holes in ordinary way. Centre -bits are recommended for all the remaining larger holes in panel, but twist -drills may be used.Drill these holes. (D)If you are going to use my Easy - Cabinet system and have not bought the - pieces ready prepared, carry out instructions /2 in this section (D).If you have bought the pieces ready prepared, skip this section (D). Cut to size and drill cabinettop(Fig.2), drilling fin. holes as advised above.Using the diagram on page 594 and keeping to the order of drawing the lines shoWn, mark out the cabinet side -pieces on the sides which will show. (E)Take the left-hand (looking from front) side -piece and top -piece and hold them together and resting on a flat surface.Prick with a bradawl through the prepared holes in the top - *1 'D/4 piece into the top of the side -piece.Insert 2k; two fin. No. 4 round -head brass screws and Doe screw top -piece to side -piece. Now do the same with the other side -piece. 3,k; Lay the assembled top and sides aside. 2' (F)Mark out and drill the terminal strip as %/jaw Fig.3.Prepare two mounting brackets as I Fig. 4. (G)Fit two mounting brackets to inside of Fig. 1.-With the aid of this diagram, which it will be seen gives sizes of holes as well as their positions. the terminal strip using 6BA round -head drilling the panel is made as simple as the other constructional work. 598 Popular Wireless, February 13th,1937.

;Continued from previous page.) (10) Coil unit terminal 2 to aerial balancing turret switch terminal B and fitted .at the other condenser fixed vanes terminal. end with a wander -plug marked Grid -2. books or cloth -covered blocks of wood ;this (11) Coil unit terminal 3 to aerial balancing (36) Coil unit terminal 11 to moving vanes isto prevent scratching ofveneer and to condenser moving vanes terminal. terminal of aerial reaction condenser. prevent pressure on control spindles. (12) Coilunit terminal 4 to1-mfd. con- (M)If you have built the Easy -Cabinet The recommended wire is of the kind that denser. frame (as I assume), fix the completed panel on termite the insulating covering to be slipped (13) Coil unit terminal 3 to turret switch the frame as follows : back,revealing the bare endofthewire. terminal A. Slacken grub screw on coil unit switch exten- " Maxamp " wire by Pete - (14) Turret switch ter- sion piece. Slip extension piece close to coil unit. Scott is about the best I . minal C to VI valveholder have tried, and isalso of . filament negative terminal. suitablethickness.Itis (15)Main tuningcon- strongly recommended as J7.12' denser fixed vanes terminal THE EASY -CABINET being very much easier to to-00005-mfd.gridcon- The Super Centurion isbuiltinto an use than bell -wire or similar I denser. " Easy -Cabinet," which consists of three stiffishwires. My advice (16) Coil unit terminal 5 pieces of wood -a top and two sides. is to use it as follows : . to main tuning condenser All the constructor has to do is to screw Cut off6 -ft. lengths at fixed vanes terminal. these three pieces of wood to the panel, a a time from thecoil as (17) .00005-mfd.grid matter of a few minutes' work, and then required.Push backin- condensertoV2 valve - he has an absolutely complete receiver. sulation about 1 in. and, holder grid terminal. 4r without increasing this lo -o. (1,8) Main tuning con- inch, slide the bunched -up denser moving vanes ter- Take the panel and slip wave -change spindle fullnessof the insulating minal to V2 valveholder through hole prepared for it in cabinet side - covering wellback along filament negative terminal. piece.Screw panel to frame, using f -in. No. 4 the wire.Using only about (19) Anode reaction round -head brass screws.Slip extension piece Fin, ofthebaredend, condensermoving vanes into position as shown on blueprint.Tighten connect the wire looping terminal to coil unit the grub screw in the extension piece. it(preferablyclock -wise) C.48ilvEr lop terminal 8. (N)Fit terminals in terminalstrip.Fit round under the terminal - l',*6 'Ai nvoaq) (20) Anode reaction con- strip to underside of cabinet top, using two 1 -in. head of the component to denser fixed vanes terminal No. 4 round -head brass screws, be wired up. is to .0003-mfd.fixed mica Shape wire along route condenser. (0)COMPLETE WIRING AS FOLLOWS : indicated in blueprint with (21) .0003-mfd.fi xed a reference,ifdesired, to mica condenser to anode (37) L.T. + ter- the photographs. reaction choke. minal on strip to (22) reaction turretswitch Allow an extra Fin. on Anode 1 terminal E. the length of the wire for choke to V2 valveholder at'aroaer connection to the terminal anode terminal. (38) L.S. - ter- it is going to.Cut through (23) -0003-mfd.fi xed minal on strip to theinsulatedwire,slip mica condenser to V2 valve - $1, V3 valveholder insulation back Fin, and, i sy4; holderfilamentnegative anode terminal. (39) H.T.+2 ter- without increasingthis terminal. minal on strip to Fin., work the bunched -up (24) Yellow lead of L.F. 6 fullnessbackalongthe transformer to anode reac- 1-mfd. condenser. wire,thuscoveringthe tion choke. .ihoo Alounimve dewc.re (40) H.T. +1 ter. minal on strip to bareness atthestarting (25)Grey lead of L.F. /6.f/V6 Aid./.44/*. aerial reaction end. Now loop the finish- transformer to 1-mfd. Fig. 4.-Two of these brackets ing end (preferably clock- condenser. are used to fix the terminachoke. wise) under its terminal - (26) Green lead of L.F. strip to the top of the " Easy - (41) Terminal E head. This detailed account transformer to V3 valve; Cabinet." on strip to 1 -mid. isofaprocesswhich holder grid terminal. condenser. actually takes only a few (27) VI valveholder (42) Terminal A on strip to volume control secondsandwillenable screen -grid terminal marked moving vanes terminal. you to do the wiring more A to aerial reaction choke. This completes the wiring, neatly and in double-quick (28) VI valveholder (P)Mark in following manner the fixing time .1212 - screen -grid terminal marked holes for grid -bias battery spar, which clamps (L) USING BLUE- A to aerial reaction con- the battery to the left side of the Easy-C-abinet PRINT, WIRE UP THE denser fixed vanes terminal. looking from the back.(Fig. 8.)Prick with BASEBOARD COM- Fig. 2.-Details for preparing the top o (29) V2 valveholder grid bradawl the lower fixing hole, which is 1 -in, up PONENTS. Do not finally the " Easy -Cabinet."Dimensions for the terminal vla 1-megohm to from the bottom edge of tho side -piece and 2 in. tighten any terminals until side pieces are given in the diagram on V2valveholderfilament from the back edge (farthest from panel).Slip a all the wires are on. page 594. - positive terminal. (1)Coilunitterminal (30) Turret switchter - 10 to VI valveholder terminal G. minal, D to V3 valve fila- (2) Coil unit terminal 9 to VI valveholder ment positive terminal. filament negative terminal. (31) Coil unit terminal (3) VI valveholder filament negative terminal 6 to lead for subsequent to V2 valve holder filament negative terminal. connection toanode of (4) V2 valveholderfilamentnegative ter- H.F. pentode VI. minal to anode reaction choke screen (fixing (32)Volumecontrol 113 screw). fixed vanes terminal to (5) Anodereactionchokescreen(fixing coil unit terminal 1. I screw) to transformer fixing screw. Two grid -bias leads are (6) V2 valveholder filament negative terminal prepared as follows : efr to 1-mfd. condenser. Take a suitable length (7) 1-mfd.condensertoV3valveholder of " Maxamp " wire, and 6S 84TERM CLAMP/MS ..174.002, filament negative terminal. prepareitas usual to Fig. 5.-The grid biasbattery is held in place against one end of the (8) VI valveholder filament positive terminal have Fin,ofbare wire 'Easy -Cabinet" by means of this simple clamping strip. to V2 filament positive terminal. at each end.Bend one (9) V2 valveholder filament positive terminal of the ends Fin. from the end back on itself lfin. No. 8 round -head brass screw through the to V3 valveholder filament positive terminal. and push the loop so formed into the hold in the hole in one end (either end will do) of the grid - side of the Belling; & Lee bias battery clamping spar and insert the point Midget wander -plug, hav- of the screw in the fixing hole just pricked. Give TERMINAL STRIP (Meow, 620.44rwE /2 Sae) ing loosened the head of the screw one turn to prevent its falling out. wander -plug.Tighten Swing the spar round until it is parallel to the 3//0 ateavire head of wander -plug. Fit back edge of side -piece.Holding spar against 6" otherendof wireto side -piece, prick through the other hole (in spar/ correct component. into cabinet side -piece with bradawl. (33) An 8 -in, lead con- Insert a second 1} -in. No. 8 round -head brass nectedtothe1-infd. screw through the upper hole in spar into 02:0 13217 condenser and having at pricked hole in side -piece.Give this screw one 1.57.12 is/92"P,}733-c the other end a wander - turn to prevent its falling out.Slip spar along a plug marked Grid +. the screws and' insert the 9 -volt grid -bias battery (34) Connect red lead between spar and side -piece of cabinet, with the - /44- ofL.F. transformerto battery sockets facing towards the back (away G.B. -1 wander -plug, from panel) and the positive end of battery Fig. 3.-The number of terminals is kept to a minimumby making some o (35)An 11 -in.lead nearest top of cabinet. the battery connections direct between the batteries themselves connected at one end W (Please turn to page 620.) Popular Wireless, February13th, 1937. 699

-72ezo-scort1 937 ALL-WAVE- PILOT AUTHOR KITS 16-2100NOMETRES S.G.3 KIT COIL CHANGING PETO-SCOTT World-wide programmes on Exact to Specification all wavelengths. Every constructor should build andhis own enjoy all the-wave thrill set of All -Wave listening that will bring programmes frontallover the world. SUPER CENTURION Pete -Scott offer you a Kit which is,in the words of a famous designer,"An amazingly efficient yet simple to build Kit set." IMMEDIATE DELIVERY -CASH -COD.orH.P ENO COIL CHANGING. SLOW LOSS ROTARY SWITCH. These are the parts SPECIFIED by Mr.JOHN CASH or C.O.D. *PRESSED STEEL DRILLED SCOTT -TAGGART and CONTAINEDIN Carriage PaidE218.9 CHASSIS. OS.G., DETECTOR and KIT "A."Any items suppliedseparately.OrdersKIT "A" PENTODE CIRCUIT. over101- sent carriage and postchargespaid. FULL Complete kit of components INSTRUCTIONS AND DIAGRAMS. s.d. and11 monthly Cash or C.O.D. 2%r7 2 Peto-Scott ready drilled and polished cabmet exactly as specified by Mr. paymentsot7/3KIT"A"Carriage Paid AO, 1 a side pieces, cabinet top and grid bias battery Complete Kit of coinpoti nts,Ice valves and cabinet. spar with 6 screws ... 3 6 John Scott -Taggart, with KIT " B." As for Kit " A," but with 3 recom- 1 Pete -Scott ready drilled and polished panel, ready -drilled paneland mendedHirai-valves.Cash orC.O.D. Carriage 16" x 12". with screws ... 3 3 Paid £5.0 3. or 91- deposit and 11 monthly pay- 1 Peto-ScOtt drilled terminal strip, 6' x 15° ... 8 Easibuilt cabinet parts, but meets of 9 3. 2 Peto-Scott brackets with nuts and bolts ... 6 1 Colvern super Centurion Coil Unit ... .,126 less valves, cabinet and Ex- 1 J.B. main tuning condenser withS.T.700knob tractor Kit. PETO-SCOTT SUPER SINGLE VALVE and pointer 56 1 J.B. aerial balancer condenser with Ismail knob 48 or SI- down and I I monthly payments of S/d SHORT-WAVE KIT 3 Graham Parish .0005-mfd.log midline NO COIL 0 Wave range 13-74 metres. condensers, S.T.800 type... 5 Easy to Build. KIT, " CT." As for CHANG- Panel and 1 Graham Parish turret switch ...... 20 KIT " B." As for Kit'Ai. but includ- ING chassis ready drilled 1 Wearlte anode reaction choke, type H.F.J. 2O Kit " A," but includ- ing setof3 specified 0 Slow motion100tolTuning 1 Lissen aerial reaction choke, type LN.5092 ... 2O ingsetof 3 specified valves and S.T.800 type 1 Lissen mica grid condenser, -00005-mfd. 6 valves. CASH or C.O.D. tablemodelcabinet. 0 SeriesCondenser elimin- I Lissen mica by-pass condenser, -0003-mfd. 6 Carr. Paid £3/19 / 0. CASH or C.O.D. Carr. ates blind spots. 1 T.C.C. 1-mfd. condenser, type 50 ... 26 or 7/3 down and 11 Paid £4118/13, or 8/9 Pluginapairofhead- 1 B.T.S. Midget L.F. transformer, skeleton type 4 monthlypaymentsof down and 11 monthly phones and listen to broad. 1 Erie 1-meg 1 -wait grid leak 10 7/3. Payments of 8/9. cast programmes a n d Benjamin 4 -pin valve holders, .3Clearetone type 6 amateur transmissions from Belling Lee type' R " terminals,A,E, ...... allovertheworld.This HT+1, HT+2, LS-, LT+ ... . 1 KIT "-CC." As for Kit " A," but including set splendid little one -valve 3 Belling Lee Midget wander plugs, Dr:id +, short-wave set will delight and entertain you at all of 3 specified valves and S.T.800 Type Consolette hours. Ample room on chassis for converting to a Maxamp wire, screws and flex 17 cabinet, CASH or C.O.D. Carr. Paid £5/14/0, or two or three -valve if desired. KIT " A," Cash or C.O.D. Carr. Paid £2 18 9 10/6 down and 11 monthly payments of1016. KIT "A"comprises complete Kit SUPER CENTURION EXTRACTOR is available, either built up or as a kit of parts, at £11410. If required of parts with ready drilled Crystal- with either of above kits add 24/- to cash prices, or 213 to deposit and each monthly payment. Please state whets inefinishsteelpanel, grey stove ordering whether kit or ready -built Extractor required. enamelledsteelchassisandall necessaryscrewswithworking drawings and operating instructions. Less valve and cabinet and head- SUPER CENTURION FINISHED INSTRUMENTS 0 phones.CashorC.O.D.Carriage TABLE MODELAssembled and built by Peto- Assembled and builtby Paid 4111510, or 2/6 down and 8 Scott experts exactly to specill- CONSOLETTE MODELPeto -Scottexperts monthly payments of 416. cation and housed in S.T.800 type table model cabinet exactly to specification and housed in S.T.800 type Con - a If required with valve and headphones £2,63. (illustrated below). 'Tested on broadcasting before des- solettecabinet(illustratedbelow).Tested onbroad - patch. Complete,butlessbatteriesand casting and supplied complete with Peto-Scott model 101 - or 413 down and 11 monthly payments of 4 3. £5.16.6 speaker,lessbatteries.CASH .07.15 .0 speaker. CASH or C.O.D. Carriage Paid Carriage Paid ow CONNECT THIS Peto-Scort Or 10/9 flown and 11 monthly payments of 10/9. Or 14/3 down and 11 monthly payments of 1413. f/CASH or C.O.D. OR YOURS 70/ma 7/ SHORT-WAVEA.c. D.c.PRE-SELECTOR "A Carriage Paid FOR TO YOUR EXISTING SET S.T. 800 KIT and 11 monthly payments of 6/4. ' and tune -in to America and Coniplete Kit of Components exactly as FIRST specified and used by Mr. J. the whole World on Short. Scott -Taggart with Konectakit(Gratis with Complete Kit) -butless wander Waves. Only a few simple IMMEDIATE DELIVERYplugs, accumulator connectors, valves, Extractor Kit, Cabinet and Speaker. connections necessaryand HIT " B." As Kit " A," but including set of 4 FIRST MIT " CT.' As Kit " A," but with valves and Peto- NO ALTERATIONS to your specifiedvalvesonly,lesscabinet and speaker,etc. Scott Table Cabinet only, less speaker, etc. Cash or receiver. Incorporates Cash orC.O.D. Carr. Pd. £4118/8, or 9/. down C.O.D. Carr. Pd. £511410, or 10/8 down and 11 sp_ocialcoilunitcovering and 11 monthly payments of 8/10. monthly payments of 10/8. 13to 74 metres, and IS equipped with an arrange- KIT " CC." As Kit " A," but with valves and Peto- KIT " CLL." As Kit " A," but with valves and Peto. ment whereby just a turn Scott Consolette Cabinet only, with speaker baffle and Scott Type " LL" Consolette cabinet only, with speaker of the switch by-passes the batteryshelf,lessspeaker,etc.Cash or C.O.D. baffle, less speaker, etc. Cash or C.O.D. Carr. Pd. Pre -Selector sothat Carr. Pd. .88/11/8, or 12/3 down and 11 monthly £8/14/0, or 12/3 down and 11 monthly payments of your setisthen payments of 12/-. 12/3. available for reception S.T.800 EXTRACTOR Is available as a kit of parts orready built at the same price,£11410. Cash orC.O.D.. on normal broadcast or add 2/3 to deposit and each monthly payment.Pleasestate which is required when ordering. *ABSOLUTELY wavelengths. SUIT- IMMEDIATE READY for USE. ABLE FOR ALI, RECEIVERS, A.C., S.T.800 FINISHED INSTRUMENTS DELIVERY *DUAL RATIO D.C. OR BATTERY, SLOW-MOTION and 11 Providing electric EXACTTO Mr. JOHN SCOTT- CONSOLETTE DIAL(8-1,100-1)monthly pay -in aimssupplyis Battery Version. meats of 9i- available. TAGGART'S SPECIFICATION Complete with FIRST *WAVELENGTHCOMPLETEForA.C. or D.C. only. SPECIFIED valves. -CALIBRATEDwithvalvesand Peto-ScottType101 SCALE. 17. 6 TABLE MODEL matchedspeakerand cabinet illustrated Battery Version walnut Consolette cabi- B.V.A. VALVES.Cash or C.O.D. Carriage Paid. Built by Peto-Scott's expert netwithAustralian technicians. Completewit walnut -veneeredfront FOURFIRST SPECIFIED and wings (illustrated valves and Pets -Scott walnut onleft).Dimensions : BEAUTIFUL 'Nag CABINETS table cabinet(illustrated on 20in. wide. 24in. high, left),lessbatteries. OVER- 124in.deep,lessbat- by Peto-Scott ALL DIMENSIONS: Width teries. Cash or C.O.D. 185;° Height 145";Depth MI'£9 : 2 : 0 RADIO CONSOLE Cash or C.O.D. 07 cn Or 1619 down and 11 Thislatest Peto-Scott Carriage Paid ew monthly paymentsof productionisanout- 13 3 d,wit and 11 monthly payments of 13,3. 1618. standing example of the bestcabinetcraftsman- ship, offeredat aprice that would be impossible W.B. SPEAKERS but for our huge produc- MODEL 37SC (Illustrated MODEL 378. Amazing re- tion and policy of selling onleft). A:cabinetinstru- production provided by new direct. . . The illustra- ment giving superb reproduc- magnet a n d exponential tionherewith cangive tion,withpower handling mouldedc o n e, Microlode but a poor ideaofthe capacity of up to 5 watts un- matching device.Cash or trulylovelyappearance distorted.Theturnofa C.O.D. CarriagePaid of this exquisite cabinet. switchadjustsItto £2/2/0, or 2/8 down Thecrossbandedand match any set made. and 11 monthly pay- contrasting inlaid walnut With volume control. ments of4/-. veneered panelsarere- MODEL 37J(illus. lieved by narrow ebony Cash or C.O.D. Car- trated on right).Per- inlays. Every cabinet. riage Paid £31310, fectly matches any band Frenchpolished. receiver as principal or Complete with shelf for or5/. down and 11 extra speaker.Cash receiver, and loudspeaker monthly payments Or or C.O.D. Carriage Paid £1/12/6.or baffle board. The Cabinet 5'9. 2/8 down and 11 monthly payments of is supplied undrilied. Drillingquoted extra. All Postal Orders should be crossed and name payable to veto -Scott Co., Ltd.All currency must be registered Cash or C.O.D. 57/6 Overall Dimensions:31" x Head Office: 77 (P.W.17), City Road, London, 18"wide X 115" deep.TakesOr5/-down and11 E.C.I Telephone: asserted 987516. panel14" X 7", and base-monthly payments PETO-SCOTT CO. LTD. board14"X 11".Speaker of 5/3. minpartment 14" x 14' x 11'Carr. & p'kg. 2/6 extra.. West End Showrooms :62 (P.W.I 7), High Holborn,London, W.C.I. Holborn 3248. gi,of .ote evolt-i4 QUiCha-CASH7C.O.D.-EASIWAY 600 Popular Wireless, February 13th, 1937. 0,000,000 WON'T GO FAR! Says ALAN IIUNTER Although this sum, representing seventy-five per cent of the total licence revenue, may seem fully adequate for the B.B.C.'s needsitmust be remembered that in order to meet the constant expansion and progress, necessitated by the desire to provide a still better broadcasting service, a very large expenditure is called for.

THANKS to Lord Ullswater and his aerial of the mast -radiator type and all the supposethatthis would produce any Committee, the B.B.C. now enjoys other refinements of modern technique. immediate revenue for the development of under its brand-new Charter an in- Again, we must admit that Newcastle and the service.It is putting the cart before come representing 75 per cent of the total Gateshead and all that highly populous the horse, entirely. licence revenue.When, as will shortly district deserves every kilowatt it is shortly Television cannot develop without large happen,theeight -millionthlicenceis to receive. financial resources.If these are to come reached, the B.B.C.'s income will be the from special television licences it will never almost astronomical sum of £3,000,000 ! develop. No one knows which came first, A lot of money, you will murmur. Surely, NEW ADVISORY COUNCIL the chicken or the egg ; but it is a moral with such an income, the programmes certainty that finance must come before MUST get brighter and better !Assuming, CHAIRMAN television. of course, that it is lack of money and not Besides, just as the B.B.C. has been lack of showmanship that has so far been given the responsibility for conducting the the reason for so many dull items. Empire Service, it has been charged with I have been looking into some of the out- the sole responsibility for setting up a standing commitments of the B.B.C.And country -wide television service. as a result, I must confess to a sinking feeling. Even £3,000,000 won't gofar Radio and Television Similarity on the present basis of expansion. For the first years there is bound to be inequity, however rapidly stations for tele- Building the Framework vision may spring up.The position is The trouble seems to be that the B.B.C., entirely analogous to sound broadcasting, like the Universe itself, will keep on ex- where, as I have said, there are even now panding. While the framework of the listeners who-paying their licence money system isstill being built up, there is the same as everyone else-are without a precious little time-or money-to fill in really first-class local signal. the existing structure with the bricks and Meanwhile, all these developments are mortar of sheer programme improvement. disquieting-not to say disappointing-to And yet, 'who shall blame the B.B.C. ? those who imagined that the new Charter Lots of people would blame it-have done would mean lots more money to improve so-if it called a halt to expansion.. For. the existing service in terms of better lots of people, even to -day, are still without programmes. the elementary right of a reliable local The technical network is the means to signal, free from night-time fading. the programme end. ; and while the network

That is why, on the present engineering is still in process of construction-as, indeed, schedule, I find so much development work it is, after all this time-the means must that will have to be paid for during the tend to obscure the ultimate end. coming year. Technical progress has always absorbed Thy Rt. Hon. the Lord MacMillan, new Chairman To begin with, there is the North Wales of the B.B.C. General Advisory Council.Lord a large amount of B.B.C. revenue. It prob. relay.Admittedly, it is only a 5 -kilowatt MacMillan succeeds His Grace the Archbishop of ably always will.Especially as London York, who recently intimated that he could no Regional-the firstof the twin centres station-but itsstation building, power longercontinuetoserveaschairman.The Supply, anti -near -fading aerial and engineer- council's functions are,briefly, to advisethe undertheRegionalScheme-is now ingstaffwill add up to quite a pretty B.B.C. on any matter relating to its programmes, definitely obsolescent and will have to be itspublications anditsgeneral policy, and to penny. promote amonglisteners a fullerinterestin replaced within two or three years. - Not that I would deny the Welsh a place and understanding of the constitutional problems, in the broadcasting sun. On the contrary, policy and practice of the B.B.C. Lack of Accommodation they have far too long been ignored, with Quite apart from such capital expendi- only a fitful mead of attention from Droit- ture that seems to have continually offset wich National. Butitrepresentsyetanotherlarge an ever-growing revenue, the B.B.C. has capital expenditure, which as usual the to face a chronic lack of administrative New Short-wave Stations B.B.C. will have to meet out of current accommodation. Then, before the Coronation in May, the income. If this wereall,perhaps the Having bought Broadcasting House lock, B.B.C. hopes to open three high -power huge licence revenue would be able to stock and barrel from a syndicate that short-wave stations at Daventry.These, stand the loss.Unfortunately, it is by no started the phenomenal pile at Portland with a vast array of new aerials for semi - means all. Place, it now has to envisage the expense beam radiation to all parts of the Empire, In the current year television will make of doubling the size of the present building. .will make a big hole in the Corporation's great encroachments upon the revenue. Demolition work on the Regency houses coffers. Exactly how great, no one-not even the adjoining the Big House is almost due to We must have a " Voice of Britain," I B.B.C.-dares to estimate. begin,It will take two years, says the suppose.Once admit the need for an Here it might be argued that there is B.B.C.'sCivilEngineer,toerectthe Imperial broadcasting link, and you must something inequitable in financing a tele- extensions, which will contain huge suites go the whole hog in combating the fearful vision service for plutocratic Londoners of offices for the overflowing' broadcasting competition of other more propaganda" - with licence' money paid over by millions bureaucrats, as well as still more studios. conscious countries. of listeners who will not-for years, anyway Taking everything into account, then, it Then, a little later, the B.B.C. will open -get the faintest chance to " look -in." is obvious that the blessing of an increased theNorth-easternRegionalstationat Some people suggest-rather fatuously, revenue as bestowed upon the B.B.C. by a Stagshaw. Thisisto be a full-blown I think-that a separate licence should be benevolent Government is-to say the least 50 -kilowattaffair.withanti -near -fading issued for television.But it is absiird to of it-a very mixed one. Popular Wireless, February 13th, 1937. 601 Why is the viii-Nts HT.SUPPLY UNITrecommended for the SUPER CENTUR ION- and,infact,for any battery set? BECAUSE the efficiency of aonly the L.T. to think about.that every time the setisOnly a Milnes Unit will give battery set is absolutelyKeep the L.T. charged andswitched on the Milnes Unityou this efficiency plus dependent on the effi-the Milnes Unitwilllook deliversfull,ampleH.T.economy, for only a Milnes ciency of its H.T. Supply andafter the H.T.The Milnesvoltage. the Milnes Unit is the most Unit has indestructible nickel - Unit is unique in the way itYou could not have greatercadmium plates working efficient H.T. supply known. keeps itself fully charged byefficiencyifyoufitteda To ensure good performance drawing current automaticallynew H.T. battery every day.physically,notchemically, from any battery set youfrom the L.T., whenever theNot only is the Milnes Unitinan alkalineelectrolyte. must keep L.T. and H.T.set is not in use; to replacethe- most efficient-it is alsoOnly a Milnes Unit has the voltages at full.When youthat used as H.T. in operatingthemosteconomicalH.T.unique system of automatic use a Milnes Unit you havethe set.Thus, it is obvioussupply.Remember, a littlerecharging from L.T.Only L.T.currentisthesolea Milnes Unit will give a running costfor a Milnestrouble -free life of 20 years Unit.L.T. charging is cheap.ormore.Ask your radio It costs only a few pence adealer to give you full details week to run a Milnes Unit. 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A weekly feature which will keep the reader au fait with all the latest news and developments in television science. Itwill appeal aliketothenewcomerto television and the advanced experimenter. * friend, turns to the receiverandre- "CAUGHT BY marks : " This is the simplestformof TELEVISION" television receiver." And, laterinthe CAUGHT by Television " is the name of a film,at a demon- " film that lives well up to its title.It stration, the direc- is one that holds much of appeal to tor just mentioned, the television enthusiast, for the technicalities casually looking of the television apparatus are by no means over the gear, com- based on the impossible. ments :" Compli- The only point not clear, and it is one that cated" in a know- can be forgiven in a film produced for enter- ing manner. On the whole a tainment, is that there are no signs of any The final stage in the preparation of G.E.C. television cathode-ray tubes.One is aerial being employed either at the transmitter most interesting seen being fitted into the metal container which protectsit mechanically and or the receiver.At the same time it is quite film,.wellworth also acts as an electrical screen. evident that a radio link of some sort is pre- seeing. supposed. multi -wire cable. Scanning has to be introduced into The parts in which a television camera is television to make it possible to do away with the used to pick up scenes from a football match multi -cable effect and to 'transmit a similar effect in a crowded sports arena are vividly reminis- "TELEFRAMES over one " wire," as in the case of the ear or sound. cent of photographs taken at the Olympic Items of general interest Games in Germany last year, and showing MULTIPLE CONNECTORS. Television experimenters will be interested to learn the television camera used then.Whether that Messrs. Bulgin have introduced some high - the " staging " of these parts of the film was PIONEER HONOURED. voltage multiple plugs and sockets for joining to- inspired by the television at the Olympic MR. JOHN LOGIE BAIRD was recently presented gether the various units. with the medal of the international Faculty of There IS a six -way one for voltages up to 5,000 Games it is difficult to say without knowing Sciences, " in recognition of outstanding contribu- and a twelve -way one for voltages up to 2,500. the dates when these scenes were shot. tions to the science of television."He is the first The plugs in both cases cost 5s. 9d. each, and the British subject to whom the Faculty's medal has sockets is. 9d.Both models are non -reversible. .

A Very Interesting Film been awarded.

Though the receiver used a small cathode- TABLE TENNIS BROADCAST. ray tube, the pictures were produced on a THE DIFFERENCE. Table tennis champions will take part in a tele- A good way of explaining the fundamental differ- vision broadcast on February 16th, when there will soreen somewhere about two feet by one foot ence between ordinary broadcasting and television be an exhibition replay of the finals of the English sixinches. So a cathode-rayprojection to -the non -technical is to draw a comparison between Optut Championships as played at the Empire Pool system could be supposed. the eye and the ear. and Sports Arena, Wembley, a few days before: The latter accepts all sound waves, however com- in' the afternoon, the present holder of the Men's Two comments, one made -by the inventor plicated, as a single wave, pressure varying on the Championship, A. Ehrlich (Poland), will be seen and one by a non -technical director of a drum of the ear. The drum is connected to the brain defending the title, and it will be interesting to note broadcastingfirm,providedawonderful by a single nerve. whether the same results will be achieved as at satire on inventions as seen from different In the case of the eye it deals simultaneously with Wembley. millions of little sections of the picture it sees.Each Table tennis is particularly suitable for television, angles in real life. little section is communicated to the brain by its it being possible to show the whole action without The inventor, explaining his apparatus to a own, nerve, all these nerves together being like a covering a wide area. * ' Now let us see what happens when a you solder a wire in place,'" another high frequency potentialisapplied 100 ohms toearth," and you will to a condenser.The capacity is, say, remember to keep it short and well TELEVISION FOR BEGINNERS `00001 microfarads, a very low figure clear of the chassis. In this article G. Stevens explains in which way a vision in -ordinary practice.At 1 -megacycle In the case of the vision receiver we frequency the equivalent resistance to have troubles with us right through receiver differs from an ordinary broadcast receiver. this capacity laonly 16,000 ohms. But the eet. In the broadcast receiver tt is at 10 megacydes the resistance drops easy to draw a line between the radio to 1,600'ohms, and at 50 Megacycles it side at fairly high frequency, and- the WHAT is there special about a vision metres wavelength has a frequency of is only 320 ohms. audiosidewhich comesafterthe receiver ? We might start a 1,000 kilocycles, i.e. a million cycles per Leaving aside the tuning of the cir- detector and which hastohandle littleearlier and say in what way second. Now a- 30 -metre signal, which cuit, think of a lead running from one currents of only a few hundred cycles. does a short-wave receiver differ from . is on what we usually call the short- condenser to another close to a metal In audio frequency amplifiers we do a broadcast receiver ?In the short- wave band., has a frequency ten times chassis.It is quite possible that the not have to worry much about the wave sets that you have seen described this, or 10 million cycles, and a 6 -metre capacity of this length of wire is '00001 losses, but only need concentrate on in " P.W." and elsewhere, there does wavelength on the `, ultra -short " band mid., which means that at 50 mega- keeping the valves from oscillating or not appear to be much difference except has a frequency of 50 million cycles.. cycles we are in effect connecting a otherwise misbehaving themselves. that 'the coils have less turns and the Every receiving set has capacity in resistance of 300 ohms between a live whole setr looks a little neater than the it, either in the form of the tuning point and earth. usual run of "-hook-ups." The reason condenser or in stray capacity, that is, No wonder the wiring of a short-wave All Radio Frequency for the C008 is,ofcourse, obvious, the small condensers which are formed set has to be carefully carried out. Now In the vision receiver It is an because -the - wavelength -of a tuned by running a conductor near another Some of these stray capacities can radio. The band of frequencies for circuit is proportional to the number with a thickness of insulation between. be avoided, but those due to the valve reproducingthehalf -tonesofthe of turns in the tuning coil; among other electrodes are inseparable from the picture requires at least two mega- things, and you will find that the coil Capacity Leakage valve, and could only be got rid of by cycles, so the radio frequency troubles which tunes to about 7 metres has only There are also the capacities between taking the valve out. From the prac- are with us right up to the tube itself. four or five turns. the electrodes of the valves-a very tical point of view this means that there In other words, the stages after the The neatness of wiring 'is an- indirect important factor because they are un- is always a lower magnification from a detector are radio frequency stages:at sign,of the difficulty in getting satis- avoidable and set a limit to the effici- given valve on the short waves, and as only a slightly lower frequency than factoryresultswithshortwaves ency ofthe valve as an amplifier. the. frequency goes up the amplification the original input stages, and we canfipt according to the conventional practice. Now you probably know that the of the set decreases. This in turn may usetheword" audio "correctly. If we wired up a short-wave set in the " reactance,as it is called, of a con- mean that we shall have to employ Instead, we usually refer to them as way that an ordinary receiver is wired denser is inversely proportional to the more valves to do the job.The only " video " stages, which is rather a neat without taking a special trouble, the frequency of the current through it. way in which we can make sure that word.The tuned circuits of the re- chances are that it wouldn't wOrk, or if Reactance is another name for the the set is giving reasonable results Is ceiver will have to respond to this very it did, the results would be very poor. effective resistance so far as the flow of to make the connections between the wide range of frequency instead of the The reason for this is the extraordin- current is concerned; and this -varies -component so short and space them so 10,000 cycles to which we are acciw- arily high frequency of the radio signal with the frequency in such a way that neatly that the stray capacity is kept tomed, -and this will mean a special which we are receiving.An ordinary the higher the frequency the lower the down to a minhnum.So when you arrangement of tuner, vihich we can radio broadcast signal of about 300 reactance... wire up your short-wave set, think, as deal with next thee. Popular Wireless, February 13th, 1937. 603 ITT PERFORMANCE THAT MUM

ehatived Condensers e L111.05 sP repeatedlY been ScottTaggart. byMr

This precision -made condenser has been specifiedagainandagainbyMr.Scott - Taggart inhiscircuits.Itiscompactin size,with accurately ganged bakelite dialectrics and solid brass pigtail connection to moving vanes.All capacitiesoi to .0005-mfd. Price Other LITLOS Condenser models at2/-.

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GRAHAM FARISH Electric Fire A typically efficient Graham Farish pro- duct. Gives more heat per unit than any other fire made. Has machine wound nickel -chrome ele- ment in focus with polishedchromium reflector.Portable, of course. Isaid it the very first time I had Allmodelsareavailable inseven attractive colours and for a Wills's Gold Flake all voltages A.C. and D.C. Price of1 -kilowatt model ...it's such a Others range from II -kilowatt at 16/6 to 3 -kilowatts at 31 6. Fromelectricaldealersand CLEAN SMOKE electricity companies. CLEAN AND SMOOTH TO THE PALATE Siovrty cifeatSAFETY ELECTRIC FIRE

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CO1:3 (.1 L..1 ce C:$ 4 CD ix oz tt-Is S v;73 0 59 (..1 z..... im STRICTLY AUTO -DIAL 7 0 c4 3 TA o c;,) z z ro. CI Z 4')Z. .0 cr tY V ®y, -A 0 4P CT X N w 44,.../I.) .4, z 4,, 4Z4 r- 3. 32 E --I rDesignecty 0 ax o IP* x --/° 00 f- fr " 2 cr14' 0 A.: 1. 4,4 § I4 0 0 ..., ,...41 4k' O o r^f,. is) eri 0 IS L., COPYRIGHT 43 ..rt4:2 Cs 4- J .... '4, 44 'CO 7 en 7. JOHN SCOTT-TAGGART ° X 14 ce a.PV A 64'4) VIte% 7 A.4.473' c. "3 e 7e- co 44 . ...r M.I.E.E., FInst..P., Fe I.I.R.E'. + 35.15 tiTp7 it% '4,1 0 44 k" I's 440 1/404., (0 k-yr 2 15 41/4 4. tiNP 1

si -00Vit' CENTERING TAB ti/"

ticO 0 0 0 O In 73 U * * THIS PRINTED COPY OF VJHIT E CELLULOID SCALES THE DIAL USED FOR THE ARE AVAILABLE, PRICE 3/ - "SUPER CENTURION " EACH, POST FREE, FROM CAN BE CUT OUT AS CELLULOID PRINTERS, INDICATED AND PINNED LTD., KINGSTON BY-PASS ON YOUR PANEL. FULL ROAD,SURB ITON, SURREY. DETAILS FOR FITTING THE CARE SHOULD BE TAKEN DIAL ARE GIVEN BY MR. TO SPECIFY "SUPER SCOTT-TAGGART ON CENTURION" WHEN PAGE 620. ORDERING. * * * 604 Popular Wireless, February13th, 1937. Popular Wireless, February13 tit, 1937. 605

CO1:3 (.1 L..1 ce C:$ 4 CD ix oz tt-Is S v;73 0 59 (..1 z..... im STRICTLY AUTO -DIAL 7 0 c4 3 TA o c;,) z z ro. CI Z 4')Z. .0 cr tY V ®y, -A 0 4P CT X N w 44,.../I.) .4, z 4,, 4Z4 r- 3. 32 E --I rDesignecty 0 ax o IP* x --/° 00 f- fr " 2 cr14' 0 A.: 1. 4,4 § I4 0 0 ..., ,...41 4k' O o r^f,. is) eri 0 IS L., COPYRIGHT 43 ..rt4:2 Cs 4- J .... '4, 44 'CO 7 en 7. JOHN SCOTT-TAGGART ° X 14 ce a.PV A 64'4) VIte% 7 A.4.473' c. "3 e 7e- co 44 . ...r M.I.E.E., FInst..P., Fe I.I.R.E'. + 35.15 tiTp7 it% '4,1 0 44 k" I's 440 1/404., (0 k-yr 2 15 41/4 4. tiNP 1

si -00Vit' CENTERING TAB ti/"

ticO 0 0 0 O In 73 U * * THIS PRINTED COPY OF VJHIT E CELLULOID SCALES THE DIAL USED FOR THE ARE AVAILABLE, PRICE 3/ - "SUPER CENTURION " EACH, POST FREE, FROM CAN BE CUT OUT AS CELLULOID PRINTERS, INDICATED AND PINNED LTD., KINGSTON BY-PASS ON YOUR PANEL. FULL ROAD,SURB ITON, SURREY. DETAILS FOR FITTING THE CARE SHOULD BE TAKEN DIAL ARE GIVEN BY MR. TO SPECIFY "SUPER SCOTT-TAGGART ON CENTURION" WHEN PAGE 620. ORDERING. * * * 300 Popular Wireless, February 13th, 1937. LEARNING FRENCH THROUGH YOUR RADIO WE will begin with DEVOIR.As I 2. Vous ne nous decevez pas told you last week, this verb isPart 47 of the special Vous ne nous avez pas degus conjugated just like RECEVOIR. Vous ne nous decevrez pas The difficulty with DEVOIR isn'tthe languageseriescontributed 3. Il apergoit mon erreur French verb itself, but rather the English Il a apergu mon erreur translation ofit.We use so many odd exclusively to "Popular Wire- II apercevra mon erreur English words here-which could be aptly described as ORPHAN words-that at 4. Congois-tu des espoirs ? best they can only be equivalent words and less " by S. C Gillard, M.A. As-tu congu des espoirs ? not translations. Concevras-tu des espoirs ? I will give you the NINE TENSES of TENSE NO. 4 IS THE BEST WE CAN 5. Les recevons-nous ? DEVOIR first, and then the English for DO FOR " I MUST HAVE." Les avons-nous regus ? the same.Remember, DEVOIR is like I know from experience that DEVOIR Les recevrons-nous ? RECEVOIR. is a terribly puzzling verb, but if you will 6. Cele nous degoit PARTICIPLES: DEVANT DO learn how to translate I MUST HAVE, TENSE No. I Cela nous a degus dois, dois, doit, devons, devez, doivent I OUGHT, I OUGHT TO HAVE, I am TENSE No. 2 certain your main difficulties will vanish. 7. Ils regoivent tout mon argent devais, devais, devait, devions, deviez, devaient The next big thing tolearn about Ils ont regu tout mon argent TENSE No. 3 dus, dus, dut, dames, dates, durent DEVOIR is that IT IS ALWAYS FOL- Ils recevront tout mon argent TENSES Nos. 4, 5, 6, 7 8. Necon ?cevez-vous pas d'autres J'ai da, etc. J'avais da, etc. plans J'aurai da, etc. N'avez-vous pas congu d'autres J'aurais da, etc. AMERICAN SINGER BROADCASTS TENSE No. 8 plans ? devrai,devras,devra,devrons, Ne concevrez-vous pas d'autres devrez, devront HER FLYING EXPERIENCES plans ? TENSE No. 9 devrais, devrais, devrait, devrions, 9. Vous l'apercevez devriez, devraient Vous l'avez apergu Now to grapple with the trans- Vous l'apercevrez lation question.The first essen- 10. Le regoit-il ? tial,Ithink,isto give the L'a-t-il regu ? INFINITIVE the three mean- Le recevra-t-il ? ings : The test this week will be on 1.To have to DEVOIR. Translateinto 2.To " am to" French: 3.To " must " I. You must imitate the pronunciation of the French announcers. Yes, I know that Nag. 2 and 2. We had tolistentothestation 3 do not exist in English.But orchestra till 8 o'clock. we will take the liberty of coin- 3. She had to do it immediately. 4.I have had to stay at home all day. ing them.Startingoff; then, 5. He had had to repeat it often. with these 3 English INFINI- 6. They will have had to say it several times. TIVES, wegetasadequate 7. She oughttohaveisolatedthe translations of : patient. 8. We shall have to leave before mid- TENSE No. night. I have to, I am to,I must, etc. 9. You ought to permit him to do it. TENSE No. 2 I had to,I was to Fair Copy next week. TENSE No. 3 I am going to give you another I had to,I was to TENSES Nos. 4,5, 6, 7 Miss Joan March, the well-known American singer, has been engaged by list of words and phrases.Let I have had to (I MUST HAVE) the N.B.C. to give special broadcasts on flying.She is seen here just us go for a stroll along a main I had had to about to give one of her microphone talks. I will have had to thoroughfareofabigcity. I would have had to(I OUGHT What shall we see ? TO HAVE) Une grande place-A big square TENSE No. 8 LOWED BY AN INFINITIVE. DON'T Les carrefours-The cross-roada. I will have to Une grappe de places-A cluster of squares TENSE No. 9 LET THE ENGLISH MISLEAD YOU Le centre d'animation-The centre of animation I would have to (I OUGHT TO) HERE ! Look atthe following nine Le trafic-The traffic Une cohue de voitures-A solid mass of traffic I think that most of the above should be sentences : Les lumieres-The lights, illuminations clear,althoughthe threephrasesin Je dots PA RLER-1 have to speak, I am to speak, Les buildings-The buildings I must speak De grande taille-Of big dimensions brackets will puzile you.It is these three Je devais A LLE R-1 had to go, I was to go De petite taille-Of small dimensions phrasesthat make DEVOIR difficult. Je dus PROMETTRE-I had to promise, I was to D'autres edifices-Other buildings They areallvery common expressions promise Les chefs-d'oeuvre de la nouvelle architecture-The J'ai da PARTIR-/ have had to leave, I must have masterpieces of the new architecture in English, and they are used just as left Les silhouettes blanches, le jour-The white silhou- frequently in French.That is why you J'avais da R E PETE R-/ had had to repeat ettes by day J'aurai da I N FORME R--1 will have had to inform Lessilhouettesflamboyantes,lanuit-Flaming MUST learnhowtotranslatethem. J'aurais da INTERROGER-/ would have had to silhouettes by night The three TENSES in which I have placed question, I ought to have questiong Les autobus-The buses them abovearejustequivalents-the Je devraiXC USE R-I shall have to excuse Les tramways-The trams Je devrais ESSAYE R-1 would have to try,I ought Les stations de Metro-The Underground stations nearestequivalents.Try to remember to try Toutes sortes de boutiques bordent les trottoirs- this, then : All kinds of shops line the pavements THERE IS ONLY ONE WAY OF Learn these nine sentences by heart, Les devantures etroites-The narrow shop fronts and APPLY THEM ! Les badauds qui se garent ou s'attardent-Shop- TRANSLATING " I OUGHT " IN window-gaters who stand about or loiter FRENCH, NAMELY, TENSE NO.9 Now for the FAIR COPY of the sen- Les magasins de modes-The milliners' shops OF DEVOIR, i.e. JE DEVRAIS, etc. tences I gave you last week: Les magasins d'accessoires de toilette-Shops for toilet requisites From this it follows that " I OUGHT 1. Je regois des amis chez moi Les magasins de beaute-Beauty parlours TO HAVE " IS TENSE NO. 7 of DEVOIR, J'ai regu des amis chez moi Les chemiseries pour hommes-Men's shirt shops i.e. J'AURAIS Je recevrai des amis chez moi (Please turn to page 619.) Popular Wireless, February 13th, 1937. 607 PROGRESS IN TELEVISION Technicians are constantly endeavouring todiscover methods of simplifying television transmission and reception.One of the biggest advances would be the elimination of scanning, and below Carden Sheils discusses this problem, describing also a new and very novel scheme. TELEVISION," as the schoolboy said, Now a valve biased in this fashion will " " is much the same as ordinary generate continual oscillations, but-and \ wireless, except for scanning, which this is the point-the wavelength it gener- makes it a lot harder."And he certainly ates is determined chiefly by the spacing said a mouthful. between the grid and anode. The difference between wireless for the Since, as already explained, this distance Pig. L-In this special transmitting valve the eye, and wireless for the ear, is that the eye varies from point to point over the whole grid and anode areset slightly askew. The cathode is coated with a photo -sensitive material,: can only look at television signals on a cathode, it follows that the valve will pro- and the number of electrons emitted varies accord- surface having length and breadth, whilst duce a band of different wavelengths simul- ing to the light and shade value of the picture the ear issatisfied to receive broadcast taneously.Further, since the cathode is focused on it. signals as a simple sequence of sounds. coated with photo -sensitive material, the at a uniform rate over the whole of its This is why in television we have to cut up number of electrons emitted will also vary surface.The grid G and anode A are in- the picture into small pieces at the trans- from point to point, according to the light - clined to each other in the same way as in mitting end, and send the fragments one and -shade value of the picture thatis the transmitter valve, and the electrodes after the other through the ether.At the focused on it. are similarly biased. receiving end they must, of course, be re- assembled in their original order on the AT THE RECEIVING END Building up the Image viewing screen. The incoming signals are applied across Doing Without Scanning the grid and the anode, and each carrier Hence, too, the need for transmitting wave automatically selects the point on the two sets of synchronizing impulses in order grid where the " spacing " favours its own to separate the picture signals intolines " particular frequency.In this way it con- andframes," as well as the necessity for trols the cathode emission at each point, in using filtering -circuits at the receiver to accordance with the received signal strength, keep all the different kinds of signals where with the result that the electrons form an they belong.Finally, it explains why a image of the original picture on the fluores- complicated time -base circuitis required cent screen F. to arrange the picture properly on the Naturally there are difficulties still to be viewing screen. overcome before we can expect tosee Altogether it is no wonder that inventors " television without scanning " in practical have tried their best, ever since television operation.But it is comforting to know first arrived on the scene, to improve or that the problem is, at least, being tackled. simplify the process of scanning.Some of The method of projecting the picture, them have even tried to get ridofit as a whole, on to a photo -sensitive elec- altogether. trode is also a feature of the Iconoscope The last idea may seem a bit too good system of television. There is, of course, no to be true, yet it has, in fact, been tackled attempt made to radiate all the picture by those who are not in the habit of chasing _....7.ki; signals at the same time, but a definite will o' the wisps. i . advantage is gained by allowing the photo- Without using any rotatingdisc,or electric voltage to build up simultaneously, rapidly -moving beamofelectrons,the 3 i over the whole surface, until it is collected picture isfirst focused, as a whole, on to ii ; piecemeal by the rapidly -moving electron the flat cathode of a special type of trans- A:1i\ stream used for scanning. mitting valve. An Accumulative Effect The Transmitting Tube In ordinary " spot -light " scanning, the As shown in Fig. 1, the cathode C is made picture voltage is generated by the swift of photo -sensitive material.The grid G passage of a single ray of light over the and anode A are also flat, and both are photo -electric cell.Naturally the photo- made of wire -mesh, so as to allow an image Fig. 2.-The scheme used at the receiving end. electriccurrentsoliberatedisalmost The incoming signals are applied across the grid of the picture P to be focused through the and anode, these being inclined to each other as fantastically small, and requires enormous lens L on to the sensitive " cold " cathode. in the transmitting valve. amplification.But by letting the picture There are two special features about this " stay put " for a comparatively long time valve.In the first place both the grid In other words, the valve generates a on a sensitive surface, and then sweeping and anode are set slightly " askew,'as different carrier -wave for each point on the up the accumulated charges by a rapidly - shownincross-sectioninthefigure. cathode, and at the same time modulates moving stream of electrons, a larger amount Actually they are also inclined to each that wave with the appropriate picture of signal energy is made available in the other in a plane at right -angles to the signal.The complete picture is, therefore, same scanning time. paper.The result is that for every point radiatedinstantaneously,withoutany Something of the same idea is also to be on the surface of the cathode C there is a time -interval, however small, between one found in the latest form of light -valve used different " spacing " or electrode -distance picture element and the next. for building -up the picture at the receiving between itself and the grid G and the It is true that a wide band of frequencies end.Instead of throwing each spot of anode A. is required to convey the picture through light singly, and in turn, on to the viewing The second point of interest is that the the ether, but this applies equally to anyscreen, a number are collected and pro- valve operates as a short-wave oscillator other system of television. jected together, so that they produce a of the Barkhausen-Kurz type.That is to Fig. 2 shows how the signals are handled more intense or brighter picture than is say, a high positive voltage is placed on at the receiving end.In this ease the flat obtainedbytheordinary methodof the grid, and only a low positive (or zero) cathode C is indirectly heated by the fila- scanning.This is one of the features of bias on the plate. ment F, so that it normally emits electrons Seophony television. GO8 Popular Wireless, February 13th, 1937.

To read about some of these superhets sw--...mmwWw ON THE SHORT WAVES nowadays leads one to suppose that the cult of the straight set is dead.But it doesn't look much like it, does it ? OINTS I should be interested to hear from other readers who are still using the " Simplex " POST -BAG Two. We might set about modernising it. - E. R. C. (W.1) tells me about some im- W. L. S.RepliestoCorrespondents provements he has made to his receiver by changing valves and by using a potentio- SO five metres has " broken out " at last -1 meter return for the grid leak.He gets 5 B Y, of Croydon, who has done THE whole bag seems to be full of letters down to the television band with a straight so much pioneer work in the past, is on this terrifically important subject receiver, and has received over 600 different reported to have been heard by W 2 H X D of QSL cards !Little did I know stations (phoneonly, I presume). He of Bronxville, New York.I seem to re- what I was doing when I spread myself on wants a circuit of an H.F. unit (real 1937 member saying, about this time last year, that tender subject. It has produced letters fashion) in the near future. that 5 metres was going to repeat the kind of all kinds ;some sympathising with the of performance that 10 metres was putting poor amateur transmitter, who is so over- A Reader's Hartley Circuit up then.This is the beginning.if there worked answering his mail ;some calling L. E. C. (Nottingham) has rigged up the hasn't been a crop of 5 -metre Transatlantic me all sorts of names for belittling the craze Hartley circuit that I described recently, contacts by this time next year, I shall be for the transference of bits of paper from and seems to be properly tied up with it. more than surprised. one part of the world to another. He has three variable condensers in it ;all We are now in the thick of the B.E.R.U. Incidentally, my remarks have evoked three of them tune, and two seem to affect Contest-that annual event that makes the from one reader the only really amateur bands in February sound like abusive letter that I ever remember the parrot -house at the Zoo !Every to have received through " P.W." A SWITCHING TIP amateur in the British Empire seemed -a distinction, indeed.I can't to be sitting on one weak signal that attempt to repeat its contents here, I was trying to resolve last week -end. but I will pass them on if you'll Australians galore, a smattering of come so close that I can whisper in South Africans, and the usual crop your ear.I imagine the reader in of " Yanks" who think they're in the question must be an old seafaring British Empire and reply to every man.If he isn't, he's done pretty call, are in evidence as usual. well for a, land -lubber. D.X. on 40 -Metres Four pin or Six -pin Coils ? The 40 -metre band is carrying a K. N. (Castlerea) is buying some surprising volume of the DX traffic. short-wave coils in the near future, It just shows what an excellent band and asks whether the four -pin or " 40 " really is; for most of the year six -pin type are the better invest- it's cram-fullof locals, but when there ment.Of course, everything de- is a real inducement to try it for DX pends upon the circuit one decides work, it never fails to turn up trumps. to use; but the six -pin coils, ob- There's no doubt that 20 metres viously, will do all that the four -pin is the wavelength for all-round long- variety willdo,and thethird distance working, though. Ten metres winding is there if one ever wants runs it very close, but only when to use it for something else.For conditions are favourable, and when all-round experimental use and for When using a metal panel make sure your L.T. " on -oft " switch is we are down in the next trough of playing about with different circuits connected in . the negative L.T. lead, otherwise you may short the sun -spot cycle I have no doubt there is no doubt that the six -pin your battery. that " 10 " will be as dead as a door coils give one more scope. nail. G 5 P B, of Barton -on -Sea, thanks me reaction as well ! But since one of them is in The news that W 3 X A L will very soon for " bursting into print about the QSLseries with the aerial, and should be left have a super -efficient beam aerial in action ramp."G 5 P B puts out phone on 40 severelyalone,onceitsmost suitable will cheer up European listeners, towards and 20 metres, and, candidly, doesn't want value has been decided on, I don't think he whom the said beam is directed.A tre- reports from British listeners.He used to can be too badly off.At all events, his mendous increase in his power over here is say so over the air, but, even so, his hall circuit values seem correct.I will try and anticipated, and this should be particularly was full of letters every morning.He's cover this more fully in an early issue. noticeableonhis 16.87 -metrewave. been driven off 40 metres in sheer self- B.C. (Garstang) reports the old, old W 2 X A D continues to be stronger and defence ! phenomenon, which crops up from time to more consistent than W 8 X K; I imagine W. R. H. (Cardiff) has a " Simplex " time-two broadcasting stations coming in that the aerial system accounts for this. Two to which he has added another resist- together when the coil of a short -waver is ance -coupled L.F. stage, and he now gets removed. This only happens when the H.T. Strong American Amateurs some twenty or thirty stations at full loud- is parallel-fed-otherwise the removal of For real strength from across the Pond, speaker volume. He asks me whether I can the coil breaks the anode circuit and nothing though, we still have to fall back on some recommend a book which explains all about can get through.With a broken grid of the 10 -metre amateurs, who really are radio, gives hints on fault finding, set con- circuit, in the old days, we used to hear fantasticallypowerfulconsideringtheir struction, and information about com- Rugby piping away on his very long wave- equipment and inputs.Quite a dozen of ponents.Candidly, I'm afraid I haven't length.Nowadays, with the broadcasting them produce stronger transmissions in come across one that fills all his require- stations using so much more power than this country than the best of the American ments and still can be recommended. they used to, we generally get Droitwich broadcast stations.If only someone would and the nearest of the Regionals, together start up some high-powered broadcast on Adding to The " Simplex " Two with any other local transmissions that are about 11 metres we should hear something. W. J. W. (S.W.8) also has a " Simplex " strong enough. It's rather late to mention it, by the way, Two, but he has added a buffer stage and a It'squitenormal,sodon'tworry ! buttheR.S.G.B.'s10 -metreTrophy, pentode output stage.He uses a moving - Incidentally,I often get queries about awarded for the best work on the band coil speaker for everything, and in the last these " quite normal " affairs, such as this : during1936, was won by Mr. D. W. three months of 1936 he received 177 short- " When I touch the grid terminal of my Heightman, G 6 D H, of Clacton. G6DH wave broadcast stations from forty-three detector I get an awful hum all mixed up was one of the most consistent stations on different countries in six continents.He with a kind of musical hum. What is the the band, and his signals could often be adds that the set is entirely made up of cure ? " Only one cure, my lad-don't heard when there was apparently nothing junk (but I presume that it is " good junk "). touch it to work with. W. L. S. Popular Wireless, February13th, 1931:. 609 Great FREE Offer toElectricalEngineers andElectricalWorkers

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THE ANNOUNCER WHO KEPT HIS WITS ABOUT HIM

(Continued from page 589.) The Koran From Cairo ? Radio Relay League (A.R.R.L.) has some 600 Radio Sets Given Away N some American cities, and especially in wonderful new entries on its roll of honour. THE Dowager Empress of Japan-to 1 Detroit, Mich., there are large com- May I hereby thank all the readers who whom be peace-has just made one of munities of Moslems who are eager to sent me particulars of messages heard from the most handsome gifts ever recorded hear the Koran read by the holy men of the the flooded areas ?I hope that somebody in the list of radio benefactions.With a Old World.For a long time there have in America will keep a record of the radio royal disregard of been vague hopes, but now a scheme is side of the 1937 floods ;it would be an thecostshe has being considered by the Egyptian Govern- inspiring story. givenaway 600 ment which promises to fulfil the need. radio receivers. The proposal is for a station of fifteen Nimble -Witted Announcer Moreover,with kilowatts or so, to be situated at Cairo, ITwas a lovely spring day in Havana, unusual under- and to work on the short waves.Itis Cuba, and the announcer was, sitting standing,she has calculated that reception in America should near the open window getting some of bestowed her be reasonably reliable, and the Rector of the morning radio advertisements off his bounty in the pre- El Azhar University, Cairo, is interesting chest. He was try- cise place where it himself in the scheme. A 100 -kw. long - ingto put some will do most good, wave station is also being considered. pep into that thank- for the lucky re- lesstask, and he cipients are all lighthouse keepers. had just read out, When he has trimmed the lamp and MIKE SLIPS AND QUIPS "This wonderful made his bed, the lighthouse -keeper has new tonic is-" During an interview before the " mike ": when a vagrant few distractions, and a spot of wireless is And in Hungary do the young people marry early or late unto him as balm and honey. No matter in life breeze whipped the how the tornadoes blow or the gales shake « * paper from his desk Advertiser speaking of beauty preparation in sponsored and sailed it round his sea-girt rock, he will always be able to Programme : hear the weather forecast. . . . so rememb.,r, ladies, if you want a beautiful face and round the room. you'll have to stetson it_ Not having heard " P.W."Contributor JoinsB.B.C. Australian cricket commentator: of the wretched tonic before, he could not Fames played that ball to mid-o8.where there was no improvise, so he had to retrieve the paper THAT popular " P. W." contributor and batsman-er-fieldsman, and they steal one radio journalist, Mr. Leslie Baily, who from under a corner piano. A minute later has been Radio Editor and corres- During Children's Hour : he reached the mike and said,rather Has anyone got a rocking horse that the children lave breathlessly, " I had to pause a moment, pondent of many newspapers, has now grown oat of? gravitated to a post which promises well folks, from sheer excitement at finding the Just before the beginning of the broadcast of a wrestling very thing I have been looking for.You'll for us, for he has been appointed Assistant bout : in the B.B.C.'s Variety Department. /3-is wearing no gown at all-just a towel round his be just as excited when I tell you.This head. truly wonderful new tonic... " and so on. Leslie Baily is probably best known to It takes an incident like that to prove if the public for his " Scrapbook " successes, Commentator describing an opening ceremony : with Charles Brewer; but this is but one of A lot of large-un%a large lot of petple have assembled. an announcer is captain of his fate. LB.'s many activities.I always had the During a sponsored programme : Look on the Bright Side feeling that one day we should B -B -seeing . . and if your eyes need the attention of an optimist, him on the staff, and now that the day has you will be well informed of the fact. WE all know that the glowing impulse come we listeners can congratulate ourselves of Generosity should be tempered as well as him. on the anvil of Tact.Remember Let's hope he finds work congenial-and O.K. for Sound that, and sort this story out for yourself. plays possible!We could do with some DESPITE the theories and the pessimists A bedridden in- more from his pen. the transatlantic route on five metres valid was visited by - has now been proved possiblefor a hearty neighbour, Band of Hope amateur communications. who bawled at the SWOPPINGexperiences with a Surrey Honour of being the first across goes to our sick man that what enthusiast the other day I nearly old friend, H. L. O'Heffernan, who operates he needed was a made myself promise myself to get station G 5 B Y at Croydon, Surrey. wireless set to myself an ultra -short -waver.For tuning His American vis-it-ms was Victor Rieb- cheer his lone 1 y there on the ultra - hausen, station W 2 H X D, of Bronxville, hours. The invalid, shorts seems to be New York; who was using a seven -valve too dazed to pro- the sort that crowds superhet when he nearly fell off his chair test, smiled wanly, every hour of listen- on hearing a Britisher chirping away at and hoped to hear ing with expecta- 3.10 p.m. on December 27th. no more of the project.Next week -end, tion.It is often an Mr. Riebhausen's report tallied in every however, in came the good neighbour with exciting waveband, way with the transmitted programme, the coils of wire and what -not. He placed a set and always band time, the frequency, the matter sent, the by the bed, asked the poor bedridden chap of hope. method of keying (carrier -keyed) and the to " Hold this aerial wire for a moment," On several occa- tone modulation frequency all checking up passed the other end of the wire out of the sions the American correctly. Congratulations -to these modern window, and climbed on to the roof. ultra -short stations Columbia ! Somewhere on that roof there must have have broken all the rules and arrived in this been a mains lead, for suddenly the invalid, country, and one chap in the Midlands has Radio's Rale in U.S. Floods who had not left his bed for years, was reported that he has picked up the Moscow Trt the tragic story of the flooded Ohio, the capering on the carpet with 240 volts television transmissions on the ultra -shorts. 1dark record of loss of life was relieved'tingling at his fingers ! As Old Moore appears to have overlooked again and again by instances of heroism No, sir.It didn't kill him. On the other this particular subject I hereby prophesy -often connected with radio. hand it gave him a new lease of life. Though that before the end of 1937 we shall hear a In communities where all normal means he had never expected to stand on his feet lot about this waveband, and that there will of communication had broken down, the again he had actually danced while the also be disorders in China. (I'm sure of the radio link brought assistance again and juice was on !He is now having electrical last part of my prophecy coming true for I again.There were some poignant messages treatment, and hopes one day to be able to have seen the casual manner in which the to be heard on short waves while the floods carry his own batteries to the charging Chinese cook slaps up a meal !) swept down relentlessly, and the American station. ARIEL Popular Wireless, February13th, 1937. - 611

on its object, isinvaluable ' atmosphere.' "Do people often try to gate-crash on the AN "O.B." IN THE MAKING microphone ? No, that very seldom happens. Everyone is very helpful as a rule. Sometimes Mr. S. J. de Lotbiniere, B.B.C. Director of "O.B's." reveals a person will yell ` Send a message home to some fascinating " behind the mike " facts about this most mother,' but thatis all.No one could intrude for more than the few seconds it important branch of broadcasting. takes to realise what's happening. WITHIN a few short weeks Room 251 a microphone and other apparatus installed. Finding Human Ghosts atBroadcastingHousewillbe As a second line was not available for con- " I remember that during an outside exceptionallybusy,perhapsthe tacting Broadcasting House we had to do broadcastfromahaunted house one busiest in the whole of the great building. our cueing by listening to a radio set. microphone was twenty yards away from For itis the nerve -centre of broadcasts " Effects play a great part in enabling the building, and the person listening for from the places where things are happening listeners to picture the scene of such a ` sounds 'suddenlycaughtfaintwhis- -big fights, the circus, fires, and so on- broadcast.Even the scream of the fire - perings. It might be the ghost, he thought. the office, den and conference room, in pumps or, better, the roar of the flames So, with torches, we went to investigate. fact, of Mr. S. Joly de Lotbiniere, Director eases the job of the commentator con- We found two individuals overcome' by of Outside Broadcasts ; and the Corona- siderably.Sounds easily recognisable like curiosity lying full length on the ground. tion is going to give him and his department the barking of a dog, the rumble of a train, They were as surprised to find the cause of extra hard work. the tearing crash of a plane propeller help our visit as we were to find them. Tall, quiet -voiced, fair-haired " Lobby," listeners to get a vivid picture of many a " Wind is perhaps the greatest enemy of as he is to most B.B.C. folk who know him feature. A broadcast from an observatory 0.B's.'On theday beforethelast well, discussed in an interview some of the in which an astronomer is studying the Grand National it was dreadful, and during " behind the mike" scenes of an outside moon through a giant telescope is very the tests caused an insistent drumming broadcast." Firstly,"hesaid," itis interesting to watch but difficult to describe noise. We had various protectors for the necessary, and in most cases possible, to so thatlisteners may enter the scene. mike ' but their use would have minimised have two high -quality land lines from the Here even the monotonous ticking of the the value of effects.So we were thankful control point of a big0.B.' to Broad- observatory clock,orthe hum ofthe that on the day of the race there was only casting House. One of them will convey, in machinery that keeps the telescope trained the lightest of breezes ! " turn, the successive output of anything from 2 to 30 microphones ;the other, used for maintaining contact with head- quarters, and for cueing purposes, is also a useful reserve line. students Different Types of Microphones " On the occasion, for instance, of a Royal wedding, ten . tofifteen microphones of types varying to suit conditions are dis- het quad ici6s `tributed at key -points. One or two are for commentators and the rest for the service itself,orforoutsideatmosphere and * Shop -boy becomes Service Engineer. effects. Each is connected by a special line to the control point, usually a hut or a Labourer becomesRadio Tester. room where the engineer in charge has a control for every ' mike.'One man alone Apprentice becomes Engineer -in - must operate them, mixing and blending Charge. the incoming speech and' atmosphere.' It is expedient, at times, so to synchronise * Bench -hand doubles his pay. the knobs that one pair of hands can, in fact, do the job.Thus one control knob R. Heath Bradley ;Principal of T.C.R.C. * Unemployed clerk gets £6 a week post. may become the master of half a dozen, operating the other five.Actually, there is All. T.C.R.C. Training is conducted by Those arc just a few of the hundreds of T.C.R.C. successes, no limit, beyond the human capacity for correspondence. You study in your own and here are just a few of the reasons why T.C.R.C. control,to the number of microphones home, at your own paces You need not training is so successful :- know anything about radio or mathe- The T.C.R.C. Specialises in RADIO.All its energies are that could be used simultaneously,or matics; a T.C.R.C. Course will take you concentrated on helping its students to become successful successively. It is simply like adding books from the elementary theory to advanced Radio Engineers. to a library. practice by easy stages. T.C.R.C. Courses The T.C.R.C. Courses are prepared by practical experts " Now and again asituationoccurs do not waste your time with a lot of use- who have .proved their ability in the radio world.The which makes a single outside control point less and out-of-date subjects ;you enjoy Courses are praised by leading manufacturers and the impossible. For the broadcast of the funeral studying and make rapid progress. Technical Press. of King George V microphones were used Every T.C.R.C. studentis under my personal super - vision and. is given individual help in obtaining well - at Westminster, in Hyde Park, at Windsor paid spare -time work or full-time, employment. Castle and .elsewhere.It was then essential SPECIMEN LESSON FREETo prove to you how The T.C.R.C. offers indisputable proof that its students to take the lines direct from each local con- easy itis to study by can and do get well -paid posts solely at a result of their troltoBroadcastingHouseforfinal the T.C.R.C. Method we will send you training. ' mixing.' a FREE SPECIMEN LESSON entitled: The T.C.R.C. can help you as it has helped others.Take " The Behaviour of Condensers in A.C. the first step to success and better pay by sending at once The Crystal Palace Fire & D.C. circuits ;Capacitative Reactance for free copy of book entitled RADIO AS A CAREER. " Although I should say that ten weeks Calculations simplified." Post coupon below. is the ideal time allowance in which to arrange an outside broadcast, we obviously have often to work to a much ' tighter TECHNICAL & COMMERCIAL RADIO COLLEGE schedule. When the Crystal Palace fire g1=1.1 NM MN Ina Mil NM =MN 1I IMF was at its height it took just two hours in FAIRFAX HOUSE, I Post in unsealed envelope :Id. stamp. (P.W.M) I To :T. ds C. RADIO COLLEGE, which 'to make an0.B.' of it from the HIGH HOLBORN, LONDON, W.C. I Fairfax House. High Holborn, London, W.C.l. I Please send, IN PLAIN SEALED ENVELOPE, Free specimen Lesson scene.The engineers tumbled into a taxi and Free Book which tells me how I can qualify for well -paid radio with their gear and, once there, they were If -you arealready employed in employ went or profitable spare -time work. NO CANVASSERS. lucky enough to find someone nearby who Radio a T.C.R.C. Course will snowed them to use a private telephone line. help you to qualify for NAME Me 'phone was disconnected and amplifiers, promotion. ADDRESS 6l3 Popular Wireless, February 13th, 1937 RANDOM RADIO REFLECTIONS By VICTOR KING

MINNIE-THE SINGING MOUSE :: THOSE RADIO PLAYS WITH MUSIC :: VIOLET RAYS AND INTER- FERENCE.

MICE-AND WHAT NOT and there being nothing to stop itit wandersoff into space, IS it a beautiful thing that a mouseshould perhaps to be picked up by be able to sing like a canary ?Now some other planet.If so, jdst wait a minute, don't answer that question think what a few thousand (or until I've put forward A Point of View. even million) kilowatts and a specially constructed aerial You will know that all this mouse business might do. started in America and that an ounce of " Well, after that I expect teeth and whiskers in the form of an you think I should be in the ordinary rodent with an extraordinary nearest asylum, or that I'm an squeak-sorry,voice-isearning£7a old crank who gets messing Here is Herbert &ma signing the radio contract for Minnie- around with dangerously high whom you see in her glass -fronted case-while Robert Kendall of week giving recitals on the films and radio the N.B.C. looks on. in the United States. voltages and what note.Well, You will also know that an English perhaps I am and perhaps I'm not, but it seems to me as though television X-ray, and all sorts of things.So they " Mouse Melba " has been caught,but has brought up to something big at last.If so, wentalltemperamental and wouldn't won't the B.B.C. be proud ?Why, they may managed to get the doctor to buy himself a warble for the be -spatted boys of the not even condescend to broadcast to us at all. metal -shielded room in which to conduct B.B.C.(Perhaps she, it or he missed the At any rate, who cares." hisnecromandes. And theyalllived homely environment of wainscoting and Quite right, Mr. Jones, who cares ?But, happily ever afterwards.Moral : A sleuth floorboards, or was dazzled into dumbness I say, do they broadcast to us, you and me in time saves nine pounds (or more) for a by such an array of Old School Ties.) and old Fred and his missus ? new set. But you may not know that the poor RADIO PLAYS WHAT AN ADVERTISEMENT ! singing Minnie has had allits glamour ONE of my pet abominationsisthe THE quality of that telephony from an debunked out of it by a biological gentleman averageradioplaywithmusic. R.A.F. plane which was put on the air who states that the " singing " is merely Usually the music is so poor that it isn't in a recent broadcast horrified me, as I expect a squeak gone wrong-through asthma. worth listening to, and the words just plain it did many others.It showed up parti- Not. sogood !We shouldsympathise piffle.Apparently the way they are made cularly badly against the first-class B.B.C. with the wretched rodent and not admire it. (I can't use any other word) is that an quality, and should never have been heard. What aboutsinginghumans ?May idea is thought of, one man writes the One can only hope that some fault had not those crooners and singers popularly " book " and someone else is brought in occurred, for it seemed too bad to be true. held to possess " gifted voices " be regarded to compose the music. as abnormal ?May it not be that their But really good musical comedies cannot WHAT'S THE IDEA ? eppi glotti, tonsils, larynxes, and other bits be built to order in such a way.The EVERY day for over a week I have re- and pieces are, I won't say diseased, but result is bound to be second-rate-unless ceived an anonymous letter bearing a abnormal or deformed ?May it not be a first-rate writers and composers are em- London postmark and containing nothing cause for congratulation if one's singing ployed.And, in my opinion, the B.B.C. but a piece of paper inscribed " DD " in tones resemble those horrible noises which hasn't got any. large block letters.Seems a foolish waste float from out of next door's bath -room If we have got to have musical comedy of pence and paper on the part of someone. windows on Saturday night? on the air (but I don't see why we should) I put it to you as an interesting specula- then past stage successes should be used. THE TELEVISION TRANSMISSIONS tion that the tenor, alto, br soprano of the But it isn't the right sort of material for ISN'T it about time the B.B.C. let us have future might find himself or herself in a broadcasting.Stage settings and choruses some official details about their tele- medical laboratory for scientific investiga- mean so much in musical comedy.O.K. vision transmissions ?I mean the way they tion instead of receiving the plaudits of a for television, but not O.K. for sound only- are getting over. You may remember that in bunch of bow -tied gentlemen in a concert unless it is good enough to hold by its the earlier days of broadcasting they used hall. music and words alone, and only master- to publish very full technical information JUST SUPPOSE .. . pieces reach those heights. about the radiations of the various stations. SOME intriguingfantasy reaches me Remember " Money For Jam," and Well, they ought to do that for Alexandra from Mr. C. R. Jones, of Worthenbury, " Mariana " ?Crikey !Them was musical Palace. We should then know how these near Wrexham. He says : comedy, them wasn't.I'd rather listen to ultra -short waves are behaving.I fear " I have been looking over my oldP.W.'s singing mice-providing they didn't sing. that the absence of information is rather and I came across your note about interplanetary symptomic of the present -thy policies of the radio in May 9th issue.Then in December ROOM FOR THE DOCTOR B.B.C. EngineeringDepartment. 26th issue you told us about the experience It is with your television receiver.The magnified I HAVE just heard the detailsof an drawing intoitsshell.Going all aloof mothballs.Theflashes.Thesmilingface. ELECTRICAL INTERFERENCE from the public it is supposed to serve. (The B.B.C. Drama Dept. should have done adventure.A listener in West London At one time it used to maintain a much those last three sentences all in rising emotion suffered simply horribly with burbs and closer contact with listeners by means of and a crash of cymbals at the end.) burps. Hisneighbourdid likewise, frequent talks on the air and friendly little "Just suppose you were the first person on earth to see someone from another world.Very thought it must be his set and so sold it publications. For an all -too -brief period the unlikely, certainly-but just suppose. and bought a new one.The new set, relations it preserved were almost ideal.I " Now, long and medium waves (sky waves) being more sensitive, had the burbs and refer to the time when Capt. P. P. Eckersley are reflected by the Heaviside Layer, and short burps even worse. was in charge. waves go through that and are reflected by It was a great loss to British broadcasting Appleton's Layer.Just suppose the raison Listener No. 1 wrote to Uncle P.M.G., thatultra -shortwavesareonlyreceived who at once sent a squad of sleuths to when P. P. E. left the Big House, for he is within a short radius from the transmitter is investigate.And what did they find ? not only a first-class engineer but also a that the sky wave penetrates Appleton's Layer, They found a doctor plying violet ray, great personality. Popular Wireless, February13th, 1037. 613

AMERICA ON MEDIUM -WAVE TWO said something, which I did not completely TheEditor, POPULAR WIRELESS. catch, about the N.B.C. network. FROM OUR READERS I am, 3ours faithfully, . Dear Sir,-I have recently become a reader West End, Bruton; Somerset.A. QUINEY. of your excellent paper. HOW LONG ISA RESISTANCE? LET THEM SAY A short while ago I made a simple two-valver The Editor, " Popular Wireless." for the medium waves, winding my own coils Dear Sir,-Although I am only a baby as far and usingmyown layout.My aerialcohsists as experience is concerned a rather amusing WHAT THEY LIKE! of about1.3feet of wire running diagonally incident occurred inthe focalradio shop.I across my bedroom.My earth, whichaeatms enteredthe shop toaskifthe owner would An opinion on the question of oblige me by measuring a resistance which was the censorship of talks. about 25 feet, is attached to an upstairs portion of the water pipe. causing a considerable amount of trouble in a set.The young man in charge took the re- About two weeks ago, I happened to wake up sistance,straightenedtheendstoaboutat The Editor, POPULAR WIRELESS. about 1 a.m., and, as the set was by my bed, I ight angles to the body, placed it along a ruler Dear Sir,-As a nation we have always thought I would see if there were any stations boasted of our right of free speech. Why is it, and measured it.I know that it sounds a bit then, that directly someone broadcasts his own still broadcasting. To my surprise I got several tall but itis perfectly true. opinions from the B.B.C. there is immediately stations, and on two of these the announcer IncidentallyInoticed that in a one-valver, was speakingEnglishwitha verystrong connecting the'phone lead remote from the an outcry from a certain section of the Press anode to L.T. T makes a little one-valver that because his speech has not been sufficiently American accent.I heard these at moderate works quite well without any H.T. censored ? strength throughthespeaker, which is a W.B. Yours truly, The sermon broadcast by the Archbishop of Stentorian " Baby " (1935 model). I concluded A. L. GRAY. Canterbury on December 13th last is a case in that these must be American stations, and my point.I amnotconcerned here with what the 26, Eaglesfleld Road, Archbishop said or whether he was right or belief was proved correct when the announcer Shooter's Hill, S.E.18. wrong, but apparently it is considered by many people, and quite a large section of the Press, that even the head of the Church in this country, must have his sermon " vetted " before we are allowed to hear. it.To my mind this is an intolerable attitude to adopt.Surely we are capable of judging what is right and what is wrong, and if we do not agree with the speaker " THERE'S A GOOD FILM AT -well, there is the end of the matter. Every newspaper I pick up contains quite a THE CINEMA TONIGHT. quantity of matter that gives me a pain in the neck, altogether apart from political opinions. COMING TO SEE IT?" Am I then to be an advocate for a censorship of the Press ? The fact of the matter is that we are spoon- fed far too much by the B.B.C. Why on earth

' should we not be allowed tolisten to con- troversial subjects 1It is only by hearing every side to a question that we are able to form our own opinions, but evidently itis considered that we should not have opinions of our own

and should be treated as if we were a lot of infants. The same papers that are making such a to-do about the Archbishop's speech not being censored, a short time ago were making a fuss because a Socialist's speech was said not to be his own because it had been censored. Do the Press really think they voice the opinion of the public IThe man in the street doesn't really care twopence what the speaker's views are. He wants to judge them for himself.. Evidently the Press think that nothing should be broad- cast unless it is acceptable to everybody, which, of course, is the height of absurdity. Yours faithfully,. A. H. SIMPSON. "NO THANKS! Ward No. 4, Essex County Hospital, Col- chester, Essex. I'M LISTENING ON MY NEW STENTORIAN" A GUINEA FOR SOMEONE Although of course some are keener on listening than Each week we present a guinea others, of this you may be sure-the proud 1937 Stentorian to the reader who, in the Editor's owner can be lured from his radio only with the greatest opinion, sends us the best letter difficulty.The new Stentorian (it is new-and remarkably on any radio subject. So why better) gives the radio artist a better chance than ever not drop us a line ? before; for it brings his voice or instrument alive in the Mr. A. H. Simpson, gets the listener's home.Yet this triumph of technique costs no From23'6to 42/- for guinea this week. more thanitspredecessors.* the chassis(or 29/6 to 63'- for the Cabinet Model) brings you a new radio delight and a * st\e THE "BOW BELLS " RECORD nk new source of pride.Ask your dealer The Editor, " Popular Wireless." ,or05.14 -to -day. acs Dear Sir,-The statement made by your cor- C.SP eoe'c,:.4"..si Models from 39/6 areavailable onhire respondent, Mr. A. H. Bartram, in hisletter c\". purchase through your deabr - from 7/6 ,9Y/ 40' V" down. (" P.W." January 16th) concerning the " Bow v:3 ,(51). Bells " record is correct.The B.B.C. Inform me ko e , that the original recording, i.e.,Columbia 4082, `2.4e.e?cs, STENTORIAN isstillin use as the interval signal, but the (.0 coo 1937 Central Record Information Bureau say that this disc has now been withdrawn from the Columbia catalogue, and is replaced by Columbia DB.1637. x2P The NEW Speaker _444 Therefore, the original disc is no longer obtain- able by the general public. With the NEW realism Yours faithfully, D. W. ALDOUS. WHITELEY ELECTRICAL RADIO CO., LTD.(InformationDept.), RADIO WORKS, MANSFIELD, NOTTS. Ilford, Essex. 611 Popular Wireless, February 13th, 1937.

QUESTIONS AND ANSWERS By K. D. ROGERS "SINGING ROUND THE RING" A COMMON MICROPHONE TROUBLE MUSIC GOES ROUND AND ROUND is an excellent amplifier and the quality is the electric light mains, will it cut down the E. G. (Tottenham).-We wish to use a very fine.I find, however, that there is rather light ? microphone and two loudspeakers in the same too much hum when the volume is turned up I am afraid you would not derive any benefit from towardsmaximum. How canthat be placing the accumulator in series with the H.T. feed. room. So far we have only succeeded in The current passing in that feed is so small-perhaps getting a howl, though the scheme works when eliminated ? only 20 milliamps, or at the most about 50-that it the " mike" is taken into another room. We In the first place, I hope you are using a screened would not make any difference to the state of charge Input lead to the amplifier.That, I have found, is of the battery under a matter of several weeks or can get it to work if we turn down the volume necessary.Twistedflexdoes not do the trick even months. control of the microphone to such a degree anywhere near so well, and the input leads should be Just think of this.Suppose your battery is of the that we have to shout into it.How can we kept as short as possible-don't let them be more 30 -ampere -hour type.It takes about 25 to 30 hours than 18 inches. to bring it up to charge at one amp.Now place it in eure the trouble-it is an ordinary carbon You can attack the hum from another angle, too. a circuit passing 50 milliamps or 50 thousandths of " mike" ? Try the effect of insert- one amp.It will take one thousand divided by ing a good, low resistance fifty times as long, or a matter of 500 hours at That's a nasty one. choke in series with the least Youareaskingfor pot of the loudspeaker. It would not do any damage to itself or to the singing round the ring, The Editor cannot accept responsibility for manu- The chokeshould be power pack, and it could be connected with the as it is called, by having scripts or photos. Every care will be taken to return inserted on the rectifier positive pole of the battery towards the H.T. + the microphone in the MSS. not accepted for publication. A stamped, side of the speaker feed on the pack, but as you will see, it would be quite a same room as the addressed envelope must be sent with every article. in the positive lead and useless thing to do. speakers.This Is a very All Editorial communications should be addressed should be accompanied difficult thing to arrange, to the Editor, Popular Wireless,- Tallis House, by a large condenser - The better plan is to have fitted a charging switch especially when the Tallis Street, London, E.C.4. 4 to 8 mfd. and fuse in the mains input to the house, on the microphoneIsofthe Make sure that you house side of the meter, and to insert your battery carbon variety. All inquiries concerning advertising rates, etc., have the amplifier there.It will reduce the voltage of the mains for Still, we will have a to be addressed to the Advertisement Offices, John properlybalancedby house use by the maximum voltage of 2, so it Will go at curing the trouble. Carpenter House, John Carpenter Street, London, means of the resistance not make the slightest difference to the lights, except Try fixingthe micro- E.C.4. on thechassis. The in theory of course. phone on elastic inside The constructional articles which appear from controliscritical and That is why the scheme is called " free " charging. a box which is packed time to time inthis journal are the outcome of therotationofthe The reduction of electricity power for household with cotton wool and research and experimental work carried out with a resistance, or potentio- purposes is so small that it is negligible-you cannot covered with thick felt. view to improving the technique of wireless reception. meter rather,isvery see any reduction of light, and you cannot detect any It may make the "mike " As much of the information given in the columns of small.You quickly go reduction of power as supplied to things like vacuum sound a little dead, or this paper concern the most recent developments Into and past the silent cleaners, sewing machines,electricirons and so even woolly, but it may in the radio world, some of the arrangements and point when adjusting. forth. also stop the trouble. specialties described may be the subjects of Letters If the amplifier is not Yet the whole of the electric current consumed In You could alsotry Patent, and the amateur and the Trader would be adjusted properly you the house by these things has to go through the placing the speakers in well adviser, to obtain permission of the patentees to may get quite a lot of battery and so charges it up.But before you fit it the room so that some we the patents before doing so. hum. make sure that you are not infringing any rules of the room is As regards your other the electricity supply people, and get an experienced a dead spot, butthis *' * question,I am afraid electrician to carry out the fitting, making sure that will be a difficult matter theIssueof" P.W." to carry out and will you mention is not now it is quite safe. need a lot of experiment.The microphone would available. We have, however, other designs in then be placed at the dead spot-still in, its box, mind which would suit your purpose, though it is not THOSE AMERICAN VALVES of course. yet decided when they will be published. I won't ask what you want the microphone in the You can attach practically any set to the amplifier I seem to have raised quite a lot of interest same room as the speakers for-that is your business. by using a resistance shunt -feed method after the But it does not make sense to me unless you want to detector, but do not forget the importance of the by my recent paragraph concerning the effi- hear for yourself what your voice sounds like on the screen leads into the amplifier. ciencyof Americanvalves.So farthe speaker.In that case, why not have one speaker Re the list of parts for the power pack you mention, majority of my correspondents agree with, the instead of two, and so assist in the problem ? you can obtain them by writing into the Query What you have got to do is to block the sound Editor of " P.W.," though he may not be able to statement that British valves are more efficient waves from the microphone as far as possible.If provide you with the circuit and wiring diagram. than American ones, valve for valve.But you yourself want to hear the speaker while you +are speaking into the " mike," you are certainly only one writer has pointed cut the price giving yourself a problem. HOME CHARGING discrepancy inthe two makes of valves, P. J. H. (Salisbury).-I run my set from and how that difference in price evens things CUTTING OUT HETERODYNES the D.C. through an H.T. power pack.I up. L. G. F. (Liverpool).-I am troubled with have an accumulator for the L.T., keeping a This is what he says :" There is no doubt about It,that valve for valve British valves are more heterodynes on my set since I bought a new spare one at the charging station.Could I efficient, but this may be a mixed blessing.On speaker.It is obviously better in the high insert this spare accumulator in series with average it takes three American valves to do the work of two British, but since the American ones notes than my previous make.How can I the H.T. feed to the set and so keep it fully cost about half the price of the British ones the cut out the heterodynes without upsetting the charged ?IVould this entail any damage ? American valves are the more efficient.The actual Would it run down by discharging through the amplification per stage is however less, and this is rest of the high notes ? probably why the Americans manage to make their It is very difficult to do so without reducing the eliminator ?If I use a charger in series with other adjacent high notes to some considerable midget receivers reasonably stable." extent.Personally, I prefer the type of heterodyne filter that can be tuned and is inserted in the anode circuit of one of the L.F, valves of the set.I assume that one of the valves in your set is resistance - coupled ?If it is the filter will probably be more TECHNICALITIES EXPLAINED-No. 39 efficient, though it can be used in a transformer - coupled circuit. The method I suggest is to join a '001 variable Microphony condenser and a *5 henry chokeinseries, and connect them across one of the L.F. valve anode The term usually used to denote a noise being pro- resistances.Most of the trouble you mention will duced by a valve, the noise being in the form of a howl probably be found to be round about 5,000 cycles. or buzz.Itis due to slight movement of the elec- If it is higher you will have to alter the series trodes of the valve, mechanical movements caused condenser or the value of choke. tsometimes by vibration from external sources such as Any good make of choke will do, but it should have trams passing the house, or to the sound waves from as low a D.C. resistance as possible, and the condenser GI the loudspeaker impinging on the valve. should be of good, reliable make. A mica preset will Microphony is not nearly so prevalent to -day as it be quite satisfactory, and the capacity is adjusted was years ago when the electrodes of the valves were until the whistle disappears oris reduced to a F not so rigidly fixed. minimum.If it is very strong you may not be able The sketch shows the main cause of microphony- to make it go completely, though you should be able movement of the grid 0 in relation to its ,spacing to reduce it to such an extent that it no longer between filament F and anode P.Such movement spoils reception, causes a mechanical control of the electrons in the valve, for the grid's influence on the electron stream is dependent on the position of the electrode in relation to the anode and filament. The nearer the grid to the space charge in the valve-round the filament-the TOO MUCH HUM more control has the grid on the electrons.O 1 shows position (in exaggerated form) J. W. (Sheffield).-I built the Paraphase during one limit of the mechanical vibration. Amplifier which you published last May.It * Popular Wireless, February13th,1937. 615

In the stage production of each play he with details which if they are not history invited the collaboration of the head boy of might easily be so. FOR YOUR the school. The Warden's object was to There is a picturisation ofthejourney BOOKSHELF encourage interest in the drama and to give of Mary and Joseph to Bethlehem and A Valuable Guide for the Service the boys practical experience in the writing events that befell them as wayfarers. There Man-Wireless Engineering :An of plays. iscolourful treatment of the innkeeper, AuthoritativeWork - Nativity With the publication of this book, which the shepherds and the wise men in relation Plays. is tastefully printed and includes certain to the birth of the Christ Child in the stable. carols, and woodcuts as illustrations, the The book is a reverent, imaginative and experiment may now have a wider scope. artistic piece of work. HERE are two recently published radio Other headmasters and teachers, seeing this works. review, may resolve to buy a copy of the * First,the" WirelessServicing book, and either use these plays for pro- NEXT WEEK Manual,"by W.T. Cocking, of " THE duction at their own schools or make them Another article by WIRELESS WORLD." Thisisa well - thebasis and inspirationof other and written handbook covering all aspects of original plays. JOHN SCOTT-TAGGART fault-finding and the adjustment of wireless Throughout, the little dramas are couched on the receivers. in simple but vigorous Anglo-Saxon, and The book commences with a chapter the treatment is imaginative, the author SUPER CENTURION on testing equipment without which no having filled in the historical background * service man can hope to carry out the necessary fault -locating tests expeditiously and logically. Following on thisis a comprehensive treatment of the methods of procedure for tracking down all the troubles likely to be met with in practice. There is a chapter on the adjustment of InIIIVAC ganging-a most useful feature in a book of this nature, and another chapter on short- wave receivers as well as valuable informa- Vv P22115 tion on loudspeaker faults. The " Wireless Servicing Manual " publishedby" TheWirelessWorld," (4 -Pin) Dorset House, Stamford Street, London, S.E.1, and costs 5s.It is a reliable guide which will be found of great value by both ehosedi 6vqi`dacht-laqqate amateur and professional. * * " WirelessEngineering,"byL.S. FOR THE "SUPER CENTURION" Palmer, D.Sc., Ph.D., F.Inst.P., M.I.E.E., is the title of a revised and enlarged edition Thisisthe valve which was specially of " Wireless Principles and Practice," by developed for S.T. Receivers. It the same author.It is intended mainly is un- to meet the requirementsofelectrical questionably the most perfectly shielded engineers who wish to become conversant valve of its type on the market. Thousands with wireless and also to cover the ground required by students preparingforuni- are in use in the " S.T.800," " S.T.T00," versitydegreesandforthewireless " S.T.800 " and the "Centurion." examinations held under the auspices of the City and Guilds Institute. Ample stocks of the HIVAC VP215 are As is only to be expected, in a work of available for all builders of Scott-Taggart's this nature a certain amount of mathe- matical treatment is included.Generally " Super Centurion."Dealers can secure speaking, the standard of mathematical additional stocks from us by return of post. knowledge required is that which would be attained by a third -year engineering student. There are over 500 pages of reading in this authoritative work, and the theory of radio is covered in a very thorough manner. For those who have had some initial vk c training in the basic principles of electrical THE SCIENTIFIC engineering this text -book is excellent.It VALVE must be understood that this is a book on wireless initsbroadest sense, and this BRITISH MADE includes'directionalwirelessand beam transmission. Theprice of "Wireless Engineering" is 21s., THE SIGN OF A GOOD VALVE and it is published by Longmans, Green & Co., 39, Paternoster Row, London, E.C.4. HIVAC VP215 Have you had particulars of these types ? * ** THE INN AT THE END OF THE WORLD and Other Plays of the Nativity. 9'6 HIVAC SHORT-WAVE VALVES By J. Howard Whitehouse (Humphrey AS SPECIFIED Milford, 5s. net.) HIVAC HARRIES VALVES This volume comes from the Warden of Obtainable from all HIVAC' MIDGET VALVES Bombridge School, and is the crystallisation dealers; if any delay, of an interesting experiment.Four years order direct. ago he wrote a Nativity Play for the boys Details of all Hivac types free for postcard. of his school to perform at Christmas. Each HIGH VACUUM VALVE CO, LTD., I I1-117, Farringdon Road, London, E.C.I year since, he has written another play, and four of them are now published. 616 Popular Wireless, February 13th,1937.

intheprogrammes.Thatis one funda- mental error which the programme producers at the Alexandra Palace are making.Still SEEN ON THE AIR objects could be conveyed by still photographs. These are moving pictures.Well, let them News and Views on the Television Programmes by our special radio -screen move ! These objets d'art are not sufficiently well correspondent defined to be appreciated fully.The glowing colours do not show.Art exhibition pro- L. MARSLAND GANDER grammes, frankly, are not a success as now presented.Some newmethodmustbe found.The programmes should be shortened AREADER of these notes challenged me vision programme.But it happened that and speeded -up. theotherday. " Youconstantly the other day I saw one.It was a film, the criticise the television programmes," American feature " The March of Time." he said." What constructive ideas have you Here was a topical magazine of absorbing An Enjoyable Item to offer ? " interest.Take two of the items-one told Ienjoyed the ice hockey programme in He went on to observe that a great deal of the story of King 'Log and his little country, which two British Olympic players appeared, listeners' money was being spent on these Albania, of his financial difficulties and how chiefly because a length of film was included programmes which were at present for the he solved them.The other concerned the with a commentary by Bob Bowman who delectation of the few.Listeners in Yorkshire, growth in Britain of the football betting pool still remains for me the finest exponent of Scotland,andLancashirewere,infact, system until it reached the dimensions of a this elusiveart.What a grand, gay in- contributing to the cost of an entertainment nationalproblem.Thesubjectsdonot consequential babble flows from him !No which they could not share. sound enthralling but they were handled so time to talk about " square 8 "-on with the In any case, he said, television is a rich adroitly thatthefilm became a human game, on withthecommentary. Heis man's hobby, with sets costing £100 each. document holding my attention more firmly one of the few commentators I know who Why should the artisan be mulcted to provide than many an " all star " romance. seems actually to enjoy himself while giving further delights for the jaded palates of the a full flowing description of every phase of wealthy classes ?And so on. Cabaret Features Are Good the game. . Well, to take the last point first,I well I have already said that in my view the Strange, but Idid not even recognise remember the day when a good 8 -valve brightcabaretentertainmentwithstar Claire Luce in the " Starlight " programme, superheterodyne, with its innumerable knobs, performers is the best studio feature, and that although I saw her twice in her last Cochran cost from £80 to £100.To -day a far better one -act plays must he sought.Tod Slaughter show. My wife and I are still discussing reasons instrument with one main control covering in " Heard in Camera " made an excellent for our curious joint failure to identify this a wavelength range, short, medium, and long, transmission. attractivestar-without,Ifear,arriving costs about twelve guineas.But if we had The B.B.C. must exploit to the full the. at any very satisfactory conclusion. never had the £80 to £100 curiosities of " outside " television broadcast.I am aware Howard Rogers was an outstanding success 1922-2G, we should never have had the that Mr. Gerald Cock isalready alive to in the Thursday cabaret programme.His twelve -guinea marvels of to -day. these possibilities.My hope is that he will impersonationsintheone-mansketch not only use television for the obvious occa- " P. -c.Hoppitt's Retirement" were most Evolution Cannot Be Skipped sionssuchassport and the Coronation suitable for close-up work, and consequently Television cannot skip any of the stages procession, but that be will also take the made effective television material.Like the of evolution. television camera to show viewers " This irritatingcharacterinso many current The £100 set of to -day is beyond doubt the London " in the many original and unexpected anecdotes I laughed and laughed ;there's no forerunner of a £12 set of the future. We ways that may suggest themselves. more ! cannot see how thisisto be done.But I demonstrated television the other day Russell Swann, the American conjurer, neither could we see way back in 1926 how to a fellow journalist, and on the screen gets better and better.I rather wish that the £80 sets could possibly come to be sold appeared thefiguresof John Piper and he wouldn't say " Isn't that silly ? "quite for £12. Serge Chermayeff discussing the picture in so frequently, but apart from that, I sincerely If the artisan of a few years hence is to themodernhome.Thediscussionwas endorse the view of Mr. Gerald Cock that he have his cheap set the programmes must interesting to a point, but on the whole too isafirst-classtelevisionartistwith the be made sufficiently attractive to keep the long-winded and slow.My friend's criticism friendly, intimate and amusing style that suits wheels of the industry turning, to create was that there was not enough movement the home screen so well. a demand which in turn will lead to mass production and lower prices.The artisan listener, the listener in Scotland, Yorkshire such tools at hand in first-class working and Lancashire is, in fact, investing for the condition. future. Is television worth all this money and A DRILL PRESERVER The following preparation will be found effort ?I can only say that when I have to be an excellent one for keeping the keen a television set to hand and an ordinary * edge of a chisel or the business end of a drill radio set alongside I never dream of looking in good order when it is not in use. in the programmes to see " what is on the pays to keep drills and similar cutting Mix well together in some convenient radio."My first mental question is always : ITtools in good condition, not only on bottle which can be easily shaken the " What is on television ? "Watching tele- account of the expense of procuring following ingredients : vision,like many other occupations,isa - replacements, but also on account of the Castor oil, oz. ;pure soft soap, 1 oz. ; habit.It will be slower to establish itself valuable time which is saved by having methylated spirits, I pint. Shake the bottle than the listening habit, bid that it will in well until the ingredients have dissolved in the end be stronger, I have no shadow of doubt. the methylated spirits. A television programme is already 50 per cent more entertaining than a sound programme. PROTECTS CUTTING EDGES Drills which are not in use should be In a year or two it will be 100 per cent better. immersed in the above liquid. value. Simple to Arrange Price Fall Will Be Gradual A convenient way of effecting this is to I do not, by the way, wish to encourage pour the liquid into a wide -necked bottle, the idea that television prices are going to and to slip the drills through the cork so drop with a bump.This is not so ;they that their tips are continually immersed will fall gradually over a period of years. in the fluid in the manner shown in the I see that Mr. J. L. Baird has been reported diagram. as stating that the prices of sets would fall in Similarly the cutting edges of chisels a very short time.He tells me that the should also be immersed in the liquid when sense of his speech was that they will fall in The liquid, on " not too long a time."He did not mean such tools are not in use. that they would decline in the immediate account of its nature, preserves the cutting future.So that on this point I find myself in edges of thesetoolsfrom atmospheric agreement with the most prominent figure deterioration, and it thus prolongs their in the tel5Vision world. working life.No longer need you find And now for the constructive ideas.I The cutting edges of the drills are protected from tools spoilt by rust after a longish period admit it is not easy to devise the ideal tele- corrosion effects due to the atmosphere. of non-use. Popular Wireless, February 13th, 1937. 617

* TECHNICAL JOTTINGS New gimes SalesCo Some items of interest IMMEDIATE DELIVERY

By Dr. J. H. T. Roberts,F.Inst.P. PILOT AUTHOR KITSCASH-C. 0. D.-H. P. :±7

A Curious Fault SUPER CENTURION KIT "A" YOURS FOR AREADER tells me of a fault which he Complete Kit of components exactly as specified by Mr. John Scott -Taggart, with ready - had with a valve, which was very drilledCarriage panel Paid and £2/18/9.Easibilt cabinet parts, but less valves and cabinet. Cash or C.O.D. puzzling at first, but which fortunately Or 5/- down and 11 monthly payments of 5,6 51- KITifB As Kit " A,"but KIT i ii BT IS As forKit"A," is comparatively rare. What happened was with3specified b u t including KIT " CC " f;'7, tKit-ine,".'44. valves.Cash or c.o.p, Carriage valvesandPeto-ScottS.T.800 valvesandPets -ScottS.T.800 something like this :When the set was Paid £3/19/0, or 12 monthly TypeTableCabinet.Cash Cabinet.prConsolette m1rrn.zarrinepaaie1 payMents of 7/3. cD.carrageia,1,, first switched on everything went quite all or 12 monthly payments of 8/9. or 12 monthly payments of 10/6. right, but after a few minutes the efficiency AIf SUPER CENTURIONExtractor is required either in Kit form or ready -built(pleaseState with any of the above Kits, add £11410 to Cash or C.O.D., pric s,or 2/3 to deposit and towhich) each would gradually gooff anddistortion monthly payment. begin to make its appearance, these two effects getting rapidly worse and worse YOURS FOR / until conditions were quite hopeless.But S.T.800 KIT "A" Balance in11 monthly payments of 6/4 SI Complete Kit of first specified parts, with KONECTAKIT (Gratis), but less wander plugs, accumulator if the set was switched off and left for a connectors, valves, Extractor -Unit Kit, cabinet and speaker.Cash orC.O.D. Carr. Paid £3/10/0. few minutes and then switched on again, KIT 'CT.' As KIT "CC " As Kit "A," KIT" CLL."As Kit 13r.k.r" " J!t.;' itsthKi4 Kit " A," but with but with valves and Pete - " A," but with valves and it worked properly, but the same cycle of firstspecifiedvalves valves and Peto-Scott ScottS.T.800Consolette Pet o -Scot tS.T.800 Conso- only, less cabinet and S.T.800 Table Cabi- Cabinet only, with speaker lette Cabinet, Type " LL " events was gone through. speaker, etc. Cash or net only, less speaker, baffleand'batteryshelf, only, with lift -up lid, and C.O.D. Carriage Paid etc.Cash or C.O.D. less speaker, etc.Cash or speaker baffle, less speaker, £4116/6, or 9/ - Carr. Paid £5114/0, C.O.D. Carr. Paid £6111/6, etc.Cash or C.O.D. Carr. Comes on Gradually down and 11 monthly or 12 monthly pay- or1216 downand11 Paid £611410, or 12/ 3 down Payments of 8/10. ments of 10/6. monthly payments of 12/, and 11 m thly p nits 12/3. The factthat what took place was If S.T.800 Extract°ris required eitherinIC't form or ready -built(pleasestate which)withanyof gradual,suggestedtheheating -upof the above Kits, add.21/4/0 to Cash or C.O.D. prices, or 213 to deposit.and toeach monthly payment. something or other and, in fact, this was BARGAIN CLASS "B" 4 KIT exactly what was happening, the " some- LIST PRICE L4 : 4 : 0 BARGAIN thing or other " in this case being the grid Latest Class "B" Circuit built on METAPLEX. 4 Stages. Variable Mu. Screened Grid high -frequency detector.Class45,- of one of the valves.In the ordinary way "B" Driver and Class "B" Output Valves. Shielded Coils. allTwin gang Al r Dielectric Condenser. feRange 200-550 and 1,000- the grid is so spaced in relation to the 2,000 metres. Working Drawings and instructions with each kit. KIT " A." All parts, less valves, cabinet, speaker.Cash filament that although, of course, it gets or C.O.D. Carriage Paid £21510, or 2/6 down and 11 fairly warm, it never gets to a tempera- monthly payments of 4/3. KIT " B." with valves, £3/13/6,or12 monthly pay- ture anything like that which is necessary ments of 6/9. KIT " CS," with valves, walnut finished Consolette cabi- to cause it to act as an electron emitter. net, and N.T.S. Class'' b" M.C. Speaker, £5115/6, or It is, as I say, very unusual for the spacing 10/- down and 11 monthly payments of 10/9. of the electrodes to be such [that the grid gets overheated and begins to emit ;when A.C. BARI:WASS S.G.4 CHASSIS it does happen it is probably due to some COMPLETE WITH 4 BRITISH VALVES accident, or to the relative positions of tiros £6 : 6 : 0 BARGAIN L3: 10:0 the electrodes having got out of adjust- TESTED BEFORE DISPATCH. Wonderfulselectivity and sensitivity.British valves.Screenedcoils.Slow-motion ment in some way. tuning.Illuminated wavelength dial.23 watts output. 200- 550,1,000-2,000metres.For A.C.Mains ONLY 200-250 You can see now why it was that the volts 40/80 cycles. Cash or C.O.D. Clam Pd. (S3/ 20;0,or valve acted quiteallright when first 51- down and 12 monthly PaYntentsof 61, In conflict, complete with Celestion Field Energised Moving -coil Speaker and Airplane dial,re loIN 0 switched on and gradually went wrong, and play.List Price £81810. Bargain Price £4/19/6, or 8/6 down and 12 monthly payments of 8 6: also why it was that on being switched off for a few minutesit recoveredits BARGAIN 1 -valve S.W. KIT W.B. 1937 SPEAKERS composure and acted normally again. MODEL 37$. Amazing reproduc- tion provided by new magnet and LIST PRICE 35 BARGAIN / exponential moulded oone. Micro - Replace the Valve lode matching device. 12-94 C.O.D. Carr. Paid £2/210,Cash or METRES 6 2/6 down and 11 If you should experience this trouble monthly payments there is really nothing that you can do to MODELof41. - 373. put it right except to take out the de- Perfectlymatches anyreceiver -as fective valve and replace it by another principal orextra speaker. Cash or one.Should it occur, however, it is worth C.O.D. Carr. Paid £1112/6. while to return the valve to the makers Or 2'6 down and 11 monthly payments of 3/-. with the request that they should try it MODEL 37SC. A cabinet instrument giving superb out, and I am sure that any reputable reproductionwith power valve manufacturer would not hesitate CompleteKitofparts handling capacity of up to 5 comprises Metapleir base- watts undistorted. The turn to replace such a valve.It is, however, board, variable and fixed ofaswitchadjustsitto condensers, switch, valve and coil match any set made.With as I say, a very unusual fault but when holders,H.F.choke, terminals, volume control. Cash or slow-motion drive,3 short-wave C.O.D. CarriagePaid itdoes occuritisso mysterious that coils, connecting wire, and FULL 4313;0, or 51- down and 11 WIRING DIAGRAM. Less valve. monthlypaymentsof 5/9. those who suffer fromitare generally Cash or C.O.D.Carriage Complete with W.B. "Lang quite mystified. Paid 19/6, or 2/6 down and 8 Arm" Remote Control. Cash monthly payments of 2/6. N.T.S. orC.O.D. CarriagePaid DOWN Lightweight headphones. 716 pr. £3118/6.or12monthly Short -Wave Reception extra. payments of 7,3. Interestin short-wave reception con- Cash or C.O.D. tinues to increase, and a great fillip has BARGAIN S.G.3 CHASSIS BRAND WITH S.G., DET. AND PENTODE VALVES been given to it by the advent, at last, of Each chaipes,t4s 1 NEW ! brand LIST PRICE £5 - television.Peopleoftenask me what andtested BARGAIN and complete with knobs and black escutcheon. CIRCUIT sort of aerial is necessary to receive very COMPRISES Screened Grid, H.F. Detector and Pentode Output Valves; Screened wave -wound coils;2 -gang Air short or ultra -short waves as low as, say, Dielectric condenser; Metal chassis;only 9 m.a. H.T. seven metres or less.Some people actually consumption;Illuminatedandwavelengthcalibrated dial; Wave range 200-2.100 metres. receive waves of these short lengths on COMPLETE RECEIVER. comprising above chassis housed in walnut -finished more -or -leasordinary outsideaerialsof Consolette cabinet with valves and P.M. speaker, Fully11; lessbatteries.Caws orC.O.D.CarriagePaid as much as thirty feet long, whilst others Tested - £317/6,or 5/ down and 12 monthly payments and 12 monthly prefer a very short aerial of only a few of 5/9 baymentsof 4/ - feet in length, which is sometimes more All P.O.'s shouldbe crossed and made payable to New Times Sales Co.All currencyonus[ be registered. efficientforreceivingtheseveryhigh 56 (P.W.20), Ludgate Hill, frequencies. NEW TIMES SALES CO London, E.C.4. (Continued overleaf.) 61s Popular Wireless, February 13th,1937.

TECHNICAL JOTTINGS Properly Designed Couplings THE NEW In order to get reallyefficient high - (Continued from previous page.) frequency amplification it is necessary that properly designed couplings should be used The point with regard to an ordinary between stages, and also that properly aerial used for medium -wave reception adjusted tuned circuits should be em- "MIDGET' is that if you want to use it for very short- ployed. wave reception you will have to reduce the If a number of tuned circuits are used, BATTERY 'CHARGER capacity ;this can be done by inserting a small condenser in series with it. not only does this improve the sensitivity, This new HEAYBERD low-tension Battery but also it has a very marked influenceon Charger incorporates a METAL RECTIFIER, the selectivity. measures 3f" x 2f" x 2f", and will charge Employing Rough Tuning a 2 -volt accumulator at f amp. FOR LESS This condenser, by the way, may be a How Tuned Circuits Work THAN Id. PER WEEK. Simply connect fixed one, but it is very much preferable People sometimes wonder why there the battery totheterminals on the to have a variable condenser so as to should be this effect on the selectivity, but charger and insert the mains lead into the give a rough tuning to the aerial.The you can easily understand it if you think nearest power point. capacity of the condenser, thatisthe about it in the following way :The first maximumcapacity,maybe0.0005- tuned' circuit rejects frequencies at either microfarad, and it is a simple matter to side of a comparatively small band or, if calibratethiscondenserfordifferent you like, confines itself to a comparatively wavelengths.But, as I say, most people small region around the actual resonance prefer a separate short aerial for short- frequency ;the second tuned circuit does wave orultra -short-wavereception,of the same sort of thing and so the chances suitable capacity. of a signal beside the wanted signal getting through two tuned circuits are very much Special Short -Wave Aerial smaller-very much less than half the With regard to the condenser used in chance of getting through the first circuit. series with the aerial, as mentioned above, The same thing applies in increasing degree Complete with mains if you are using an ordinary type of aerial to further tuned circuits. lead and adaptor ... it is a simple matter to arrange so that this SEND NOW for full details of this remark- condenser can be put in or out of circuit. Doing Away With Reaction able Battery Charger. 6 The special short aerial for ultra -short- Another advantageofhigh -frequency wave reception may consist of a few feet of amplification, altogether apart from the wire rigged up indoors, so that really there M question of the selectivity or sharpnessof is very little point in going to the trouble tuning, is that it is generally possible to Address of making one aerial serve both purposes. dispense with reaction.We know that PW.T. reaction is a very good servant, but is also Receiver Range 10 FINSBRY ST. a very bad master, and although it has F. C. HEAYBERD & CO. LoNDON,UE.C.2., The range of a receiving set, what is served us in good stead. for many years now, rather vaguely calledits" sensitivity," I think you will agree that if it can be done depends a good deal upon the amount of away with, and the same result obtained high -frequency amplification which is pro- without it, so much the better, because in videdbeforethedetector.Ofcourse, getting rid of reaction you also get ridof the sensitivity or range of the set does not the great liability to distortion. depend entirely upon this ;itdepends upon other things, upon the efficiency of The Time Base thereceivingaerial and various other Many people who understand broadly factors, but generally speaking the amount the modus operandi of television reception ofhigh -frequencyamplificationisthe are a bit confused as to what is meant by LIGHTNING ARRESTER predominating factor. the term " time -base." It is easy to see why this should be so, WITH THE GUARANTEE21 As a matter of fact this is really very OF £200 because the detector. can only deal with simple and it refers to the " scanning " of Act now Don't run risks.Lightning what is delivered to it, and although there the receiving screen of the cathode-ray tube. may ruinyourset,your home, your is often a small amount of amplification verylife.Forget these dangers with a In order to explain what it means, letme GARD, from alldealersorpostfree taking place in the detector stage itself, just run over what actually happens in a from : the detector has to rely practically-almost cathode-ray television tube. -As you know, GRAHAM FARISH LIMITED entirely-upon the incoming signal strength a beam of electrons shoots through a very Masons Hill, Bromley, Kent being boosted up before it arrives there. fine hole and passes on to hit a fluorescent screen, but in the early stages of its journey ING INEEARNING H.F.Amplification it travels between two pairs of parallel ERS Ia Some peoplethinkthatthehigh - metal plates, the plane of one pair being set AREYO ..0 frequency amplifying stages are mainly at right angles to that of the other. Electrical LEST concerned with the loudness of the repro- potentials are applied across these two pairs If so, youTHAN cannot afford ,L to 10 carry PER on without WEEK? reading of plates and the stream is deflected and our 268 -page Handbook.The book explains clearly duction.Well, naturally anything which and definitely many ways of carving out a successful increases the signal strength delivered to made to traverse the screen by means of career. Among other things it explains the Services ofourunique Appointments Department,outlines the detector will, other things remaining the variations in these electrical potentials. Mechanical,Hotne-StudyCourses Electrical,inall Motor,branches Aero,of Wire-C1v,11, the same, increase the volume of repro- less,Television, " Talkie "Eng., Building, Deflecting the Beam Govt. Employment, etc.,and ewes detailsof duction, but when you are searching for A.M.I.A.E..A.M.I.R.E.A.M.I.W.T., G.P.O . weak stations (or for powerful stations Now one pair of plates has the effect of - MAT/tiC., and all Exams. We alone Guarantee-" No Pass-No Fee." which are so far away that the signals are shifting the spot where the beam hits the Whether you be an old hand or a 1 budding apprenticegginlikthis POSTb9 weak by the time they reach your aerial) screen up and down (or left to right,it 1FREE. you are not likely to overdo it in any way doesn't matter for the moment) whilst the IBRITISHINSTITUTEOF ENGINEERING TECHNO- in regard to the strength of signals actually other pair of plates shifts the beam across LOGY, 101, Shakespeare House, 17 19. Stratford Place, delivered to the detector.In other words, the screen.The result of the combination London, W.I. the primary purpose of the high -frequency of these two types of motion is that the amplifying stages is to bring up the signals spot of light covers the whole area of the toavaluewhichthedetectorcan screen in much the same way that your eyes PLEASE BE SURE TO MENTION adequately and efficiently deal with. After scan a column of type.The time -base is "POPULAR WIRELESS" WHEN that,itremains forthe low -frequency the arrangement by which the potentialsof COMMUNICATING WITH stages to do all the real boosting up of these plates are controlled so as to make the ADVERTISERS. THANKS! the sound volume. spot traverse the screen in the desired way. Popular Wireless, February 13th, 193'1. 6IC) tr FOR THE

CONSTRUCTOR giveyour Two practicalhints worth knowing.

A SOLDERING TIP THE greatest bugbear in soldering is the dirty condition into which the copper SUPER CENTURION bit gets every time it is heated. A piece of block sal -ammoniac, with a small hollow scooped out and filled with colder, will be found to be the best cleanser agood start. that one could wish for.It keeps the iron thoroughly clean and coated with solder, and has the additional advantage that when . . . withthis handsome J.B. Main Tuning it becomes slightly charred the solder is Condenser.Mr. John Scott -Taggart, Britain's easily removable from its bed, which a foremost set designer, had it constructed to his moment's work with a knife will restore to a fine whiteness. own requirements, and itis specially matched This will not, unfortunately, prevent the to the circuit. He also specifies a J.B. Aerial formation of the ugly black scale which is Balancer Condenser, .0005 mfd., which costs 4/6. bound to appear on the iron before it is in Secure these two fine components at once, and use very long. A piece of old file, which start building this great coronation set NOW ! has been softened and screwed to the bench, is very useful for removing scale, as a light rub along the rough surface will take off the hardest deposit.To soften the file, heat it to a cherry red and allow it to cool. Main Tuning Condenser, specially matched, ACCUMULATOR POLARITY IFyou are ever in any difficulty in the with knob and long pointer. determination of the polarity of the Complete plates of an accumulator, it is well to ®6 remember the fact that the positive plates in a healthy accumulator are generally of a dark -brown colour, whilst the negative plates of the accumulator have a greyish appearance. JACKSON BROS. ( LONDON) LTD., 72, ST. THOMAS ST., LONDON, S.E. I It is easily possible to tell which is the positive and which is the negative plate grouping of an ordinary accumulator, pro- vided that more than two plates are present in the cell. In such cases, the positive group of the accumulator has always one plate "SUPER CENTURION" "R" TYPE TERMINAL less than the negative group. Themost popular with Components specified by the constructors, as with set LEARNING FRENCH designer... manufac- for a good job well done turers. 52 THROUGH YOUR RADIO available in- (Continued from page 606.) dtLettered cations. s. d. white; Bake- liteinsula- Leschemiseriespourdames-Ladies'underwear Terminals :Belling -Lee Type " R " ted; black shops non - remov- A, E, H.T.+ I, H.T.-H2, L.S.-, able rotating Les chapelleries-Hat shops head; 4 B.A. Les drogueries-Chemist shops and 1 stem Acheter une specialite pharmaceutique-To buy a Six at 3d. each .. . 6 collar. Im- patent medicine In connectorprovedsub - Faire executer one ordonnance-Ta get a prescription Wander Plugs : nuts. made up En4M No. 1003. Choisir des cigares-To select some cigars Beliing-Lee " Midget" 3d. each. Boire un ice-cream soda-To drink an ice-cream soda Un bar arnericain-An American bar Type Grid -F, Grid-I,Grid -2 Une bouteille de gin-A bottle of gin "MIDGET"

Une botte de friandises-A box of dainties Three at 2d. each .. . 6 ANDER Un appareil photographique-A camera Un m pertne able-A rain -coat rilit ,t},it PLUG Les debits de boissons specialises abondent-Shops For the Triple Extractor : I T h r e eprongs. 40/ hard - drawn for specialised drinks abound spring wire; 3 Le bar qui sert les cocktails, le vin, les liqueurs fortes " R "TypeTerminals,A. I,A.2, il paint contact

-The bar which serves cocktails, wine, strong drinks l 6 1 Bakeliteindicatchianps La soda fountain-Soda fountain Two at 3d. each.. hexagontopto Les boissons rafraichissantes-Refreshing drinks aid use of tools Les glaces-Ices andtoprevent rolling. A masterpiecein Le bar restaurant-Restaurant bar TOTAL 2 6 miniature. Le " Tout est bon "-Ditto Sea. 1276. 2d. each. Le " Tout va bien "-Ditto L'automatique-Automatic machine Un etalage-Shop-window display Get the Complete Catalogue Belling & Lee Ltd., Sur les trottoirs une collection d'officieux-On the Free. Comprehensive folder -catalogue, in Cambridge Arterial Road, Infield, Middlesex. pavements a collection of officious small -traders convenient pocketsize," Radio Connec- Les camelots-Street hawkers tions." Special: the new 46 -page book STRIKE OUT ITEM NOT REQUIRED. Les marchands de journaux-Newspaper sellers containing 150 illustrations, including 75 blue -prints of curves, diagrams, circuits, I enclose8d.for newbook, " Radio & Electrical Les marchands de fleurs naturelles-Flower sellers constructional details and speCification of Accessories." Les marchands de fleurs en papier-Artificial-flower everypart.Invaluabletoconstructors. Pleasesend, free, "Radio Connections " folder. sellers Post free 8d. Les marchands de petits jouets-Toy sellers Les cireurs de chaussures-Bootblacks Name Les valets de place-Messengers L'etranger-Foreigner BELLING -LEE Address Les curiosites de la ville-The sights of the city FOR EVERY RADIO CONNECTION Des taxis stationnent le long du trottOir-Taxis are parked alongside the pavement Pop. W. 13/2/37. Its maraudent-They crawl along (fare -hunting) - 620 Popular Wireless, February 13th, 1937.

There are 16 small circles with white centres THE SUPER CENTURION along the border of dial.Keeping dial flat on ELECTRADIX BARGAINS RAPID CONSTRUCTION panel, start with the top circle and prick through TRANSMIT VALVES, NEW VT13B. A 'fine 30 - centre of circle with some thin pointed instru- wetter 6-v. 11 -amp. anode 1,500-v., imped. 35 thou., GUIDE ment (I used a drawing -pin) for about 1.16 in. mag. 35.Less than half price,25/-. AT50 5 -Guinea line. 7-v. 24-a., 1,500-v., wag. 30, as new, 25/, Big Insert a prepared pin into this hole and push Rectifiers, NU2, 5-v. 24-a., 250 watts up to 20,000-v., (Continued from page 598.) home with any hard, flattish -headed instrument 45/-; 10,000 volts 2 m/a., 35/-. 100-watp T3T2A, 45/-. (I used the handle of a screwdriver). Carry out Also a few okw. bottles cheap. Taking care that the voltage figures on side of THE SUPERSEDER makes the rest of the fastening -down of dial in following H.T.from yourL.T.2 -volt battery remain in view, screw up spar fixing order:Circle between pin just inserted and battery, rectified and smoothed. screws untilbatteryisfirmly clamped into condenser spindle ;the two circles (on outer EASTERN' Three tappings.Lastsindefln. (If you have used screws that are too itely.A.boon.List8315s. position. border) on each side of top circle ;the two New, guaranteed, 37/6. long, you will need to put cardboard or a wad of TELEPHONES. The cheapest circles (on inner border) between last -inserted is a pair of 2/9 Sullivan phones. paper between spar and battery, otherwise two pins and spindle. Carry on in this' way, Brown's " A ". reed for short- screws would go right through cabinet side. wave sets. 1,500 ohms, 21/6; 120 ohms, 17/6. Western working towards the ends, keeping dial fiat. Elec., 2,000 ohms, 4/3 pair.4,000 ohms T lightweight, piece.)Fit G,B. + pluginpositive(plus) (S)CUT CENTERING TAB OFF WITH 4/6.Single high res.earpieces,2/8.'WallorTable socket, G.B. -1 in 3 V. socket, G.B. -2 in 4 V. SAFETY -RAZOR BLADE by cutting along Housephones, 25/, socket. DOUBLE CURRENT DYNAMOS. D.C. 600 volts, inner border where indicated (where tab is 100 MA., and 6 volts 3 amps, 32/6. (Q)The dial (or scale, as it is often called) COMPASSES. Boat Binnacle Mariners'6in.Boat may be of paper, card, or white celluloid, and is Compass, floatinggimbalglasscase, 35/,Magnetic similar to that used on the S.T.700.The S.T.700 Compass, Him Brass Case. bevel glass, plain dial, un- sealed, new, 9d. War Office Prismatic, 25/-.Travel- celluloid scales (which are very slightly out of ler's pocket, 15/ -- date as regards station names), are obtainable for SUPER CENTURION SHORT WAVE 2 -pin short wave coils,3, 4, 5 and 3s.postfreefromCelluloidPrinters,Ltd., 6 turns, 1/-.Steatite lead-in with brass stem, Sd. 3in. THE POWER SUPPLY stand-off insul., 6d. Kingston By -Pass Road, Surbiton, Surrey. Batteries : H.T. 120 v.-Drydex, G.E.C., CABLE AND WIRE. Lead -coveredsingle,3/029, The following applies to the fitting of the Milnes H.T. Unit, Fuller, 7/. 50 yds.7/029 ditto, 12/- per 50 yds.L.C. Twin, Leaving the centering tab attached, 1/.064, 12/- per 50 yd. coil: L.C. Twin1/044, 16/- paper dial. Marconiphone, Ediswan. per 50 yd. coil.Plain V.I.R. lighting, 11044, 5/3per cut out dial along borders.Cut out (razor G.B. 9 v.-Drydex. 100 yds. Heavy Mains Flex, 4/- per doz. yds., post 6d. blade essential) the hole for slipping over bush, L.T. 2 v.-Exide, Fuller. Twin lighting Flex, 2/- per doz. yds., post 40. AIR where marked on the tab.Stand the set up in COMPRESSORS for Paint Spraying,SetCleaning, SUITABLE LOUDSPEAKERS Inflation,etc., Foot Operated, 3716.Electric No.1 its normal position, front of panel facing you. size, .45/15/-. The moving vanes of the main tuning condenser W.B., British Rola, Blue Spot, Wharfe- MORSE & SIGNAL dale. (No significance attaches to the KEYS,51-,716,18 6 should be " closed." Put your left hand round and25/-.BUZZERS, order of makes.) J. S. -T. I., 2/6 and 51-. SOUN- the back of the set and gently hold the rear end DERS,5/-, 7'8and framework of main tuning condenser. Do not * * 10/ - Morse Practice Setscomplete, 4/9. touch the vanes.Remove the fixing nut and BELLS,circularDesk, washer from the main tuning condenser's spindle joined on).Tear away the tab from the con- vibrator in gong,2/-.Wall portion, which can be seen from the front of the Bell Pushes, Porcelain, denser bush ;there is really no need to remove 24in., 8d. or 5/- doz.Brass Pushes, 9d., 1/6 and 2/6. panel. the fixing nut to do this.Tighten up the fixing Pendant Pushes, 6d. Slip the hole in the centering tab over the 'WIRE -WOUND POWER RESISTANCES. 5 watt nut on bush of main tuning condenser. 8,000 ohms, 10 m.a., 10d. 5 -watt Potential Dividers, spindle bush (the threaded brass collar), and STAND SET IN ITS NORMAL POSITION tapped 50,000 ohms. 1/6. hold centering tab against panel by fitting washer WITH DIAL FACING YOU. Mains Transformers, 3/6.1-mfd. Condensers, 4d. (T) H.T. TRANSFORMERS. 200-240-v.to10.000-v. Turn projecting spindle of main tuning 24 ma., 34/-; 5,000 volts 20 m.a.. 19/6; 2,500-v. 15 condenser fully anti -clockwise (fully left).Slip m.a., 17/6. Large Coronation Neon Signs, 4ft. 2in. X 4ft, llin. x 6in., on glass panel, ready for use, £7. the large J.B. knob and long pointer on to end METERS.-DI1C-ONENETER, 50 -range mieroamps., of spindle w;th the pointer pointing exactly amps., milli -volts and volts, ohms and megs., all in one horizontally to the left. Tighten grub -screw, Precision moving -coil Meter with multipliers.Accurate which is the little screw which fits into edge of and marvellously cheap, 55/-. Multipliers extra. Worth As/DE OF AcHr SDE-P/EcE £10. The' Dix-Mipanta " is an A.C.-D.C. mains -vest- knob and is on opposite side to pointer. (Do not pocket.bakeliteVoltmeter.List£2.Trade19/6. Micro -Ammeter 24in. panel 0-50 m/ma, 40/-. touch screw which secures the pointer.) 1,000 Switchboard, Service and panel Meters in stock, (II)Turn spindles of volume control, turret lowest prices.Meters, all ranges. 50 microamps, 40/-. Weston Table Meters, 18/6. Charging Pole Testers, 216. switch, anode reaction condenser, aerial reaction 0-20volts,5/-. 0.50volts,5/..0-100 volts,5/6. condenser, and aerial balancing condenser fully 0-200 volts, 6/, All A.C. or D.C. Repairs to all types. anti -clockwise (fully to left).Fit their knobs 1,000 other bargains in New Sale List "P," post free. with their white spots or pointers exactly in a ELECTRADIX RADIOS, horizontal direction to the left. Tighten up 218, Upper Themes Street. London, E.0.4. 'Phone: Central 4511 their grub -screws. (V)Fit knob on wavechange switch spindle (no special direction). YOUR SET IS NOW COMPLETE. (See %%N.% %%%%% .4.10.000.10.% separate article next week on installation and operation.) Please be sure to mention 3. S. -T. "POPULAR WIRELESS" z" when communicatingwith MY CORONATION SET Advertisers. Thanks! (Continued front page 595.)

R.46414N 6)1VING by the application of reaction, and there is 7/ONS 0,,,f TART/HO Nee ES no need to reduce the aerial coupler. This in W/7"li A 44:40.4.Z. A-0.26.8 W.B. STENTORIAN SPEAKERS eArtERYSR4o2 P/AWY6 itself adds enormously to signal strength The Finest Permanent Magnet Loud- .ince-Avs on weak stations, while preserving good speakers onthe market, supplied - on lowest terms :- selectivity. The whole matter has been 378: Cash or C.O.D. 42/-, or 2/6 /" down and 11 monthly payments discussed at great length in connection of 4/-. with the S.T.600.I am more than ever Fig. 8.The 0.B. battery clamping spar is screwed GARRARD TYPE "B" into the position shown here. delighted with aerial reaction as being a RADIOGRAM UNIT means of greatly increasing both sensitivity (consisting of Garrard Electric Motor and Garrard High-grade and then nutloosely.Layset(inEasy - and selectivity. Pick-up).Cash or C.O.D. £3/2/8, or 6/6 with order and Cabinet) on its back, front of panel uppermost. Selectivity on the anode circuitis ob- 10 monthly payments of 6/3. Centre the dial into its correct general position ; as a guide it may be noted that the top point tained partly by reaction and partly by PROMPT DELIVERY. Anything and everything Radio should come opposite the middle fixing screw of reducing the load of the anode circuit of supplied on lowest terms. the first valve. THE LONDON RADIO SUPPLY CO., LTD., panel (i.e. half -way along top edge). This is done by applying a 11, Oat Lane, Noble Street, London, E.C.2. Ensure dial is in correct position by measuring negative potential to the grid.This is done the distance from the lowest point on the left- by a two-way switch which is a Graham- hand end of dial to the bottom edge of panel; this distance should be the same as that from the Farish turret switch.In one position the All applications for Advertising Space right-hand end of dial to bottom edge of panel. set is switched off.In the next position, in " POPULAR WIRELESS " should be (R)Prepare 16 ordinary plated brass pins half -way, the set is in its most selective ; addressed to the Advertisement Depart- (if a pin is of a type that could be bent, it can be condition, with negative bias applied to the used) by cutting them diagonally with wire - grid of the first valve.In the third posi- ment, John Carpenter House, John cutters or pincers about it -in. from their heads. { CarpenterStreet, London, E. C.4. You now have 16 very short and pointed pins. tion, the set is working at full sensitivity, ea Any other type of very short miniature nails but selectivity is rather less. may be used J.S.-T. February 13th, len POPULAR WIRELESS

MISCELLANEOUS RECEIVERS, COMPONENTS AND 1936 BROADCASTING ADVERTISEMENTS ACCESSORIES Surplus, Clearance, Second -Hand, &c. REVIEWED (Continued) The work of the West Region 3d. per Word 6d. per word for first words in heavy type 1937 SHOW MODEL," PYE INVICTA " ALL -WAVE. 6i- Per line for displayed lines (12 Pt. type) Brand new in sealed cartons.All -Electric, 200-250 volts A.G.Tunes from 17-2000 metres, 4 Mullard of regionalhead- Minimum Charge 3/ - valves. Large heavy-duty Mains energised Magnavox rr HE West England Remittance must accompany Order. moving coil speaker.In handsome WalnutCabinet. '. quartets were greatly extended during List 59/9/0. Our price 55/19/6 complete. Cash with 1936.'Studioaccommodation, which order. 100 only.." Speed," 732,Rornford Road, Advertisements for these columns ere London, E.ta.I L F. 2316. proved a problem during the early part of accepted up to first post WEDNESDAY the, year, was extended by the construction MOR NI NG for thefollowing week'sissue. HEADPHONES. 5,000 GuaranteedPairstobe ofanew studio. cleared. Brown, G.E.C., B.T.H., Ericsson, Never, The Proprietors have the right so ',flue or WesternElectric,Siemens,Brandes,Sterling,etc. Under the title " Western Salon " a new withdraw advertisements at their discretion 2,000 ohms, 2/6 ;4,000 ohms, 51-. Postage 6d. experiment was tried.Chamber Music was Postal orders in payment for advertise- SPECIAL. Telefunken,adjustable,lightweight. played to an audience gathered round the ments should be made payable to The 2,000, 4,000 ohms, 7/6. Amalgamated Press, Ltd., and crossed. CRYSTAL SETS. burne.Jones, Complete, Guaran- players so that a more intimate atmosphere teed, 5/6.Ditto, double circuit, 8/-. With permanent might be created than in the concert hall. All communications should be addressed detector, 1/- extra.Sensitive permanent detectors, Broadcasts in this series included the Griller to Advertisement Department, "Popular 116. Crystal detectors. Completeparts, 1/.. Wireless," John Carpenter House, John Crystal, 6d. PostRadio,183, Caledonian Road, Quartet from Dartington Hall, the Grinke Carpenter Street, London, E.C.4. Trio from Marston Court, andthe Bristol London, N.A. Chamber Music Players from the studio. 111 CONDENSERS. Metal Case. British Manufacture Broadcasts from public concerts included (by Specialization Method).1,000 -volt wkg.1 mid., RECEIVERS, COMPONENTS AND 2/9, 2 mfd.. 3/3, 4 mfd., 4/9, 8 ofd., 8/6. 800 -volt wkg. the opening concert of the Torquay Musical mfd.,1/9, 2 ofd., 2/3, 4mfd., 3/9, 8 mfd., 0/6. Festival and the concert to mark the re- ACCESSORIES 500 -volt wkg. 1 mfd., 8d.. 2 mid., 1/2, 4 lnfd., 1,10, opening of the Colston Hall. Surplus, Clearance, Second -Hand, 8 mfd., 3/6. Condensers. Tubular, -005 ofd. to 2 ofd. Condensers.Television, P.A. systems, etc.List on Outstandingdramatic andfeaturepro- application. S.A. E.Mentone Radio Stores, 304, grammes oftheyearincluded " Barnet's SOUTHERN RADIOS WIRELESS BARGAINS. Fulham Road, London, S. W.10. Folly," by Jan Stewer ;" Treasure Island," All Goods Guaranteed and' sent Post Paid. LouisStevenson,adapted by RECEIVERS.- VIDOR. 3 - ValveBatterySets. CONVERSION UNITS for operating D.C. Receivers by Robert ModelC.N.212. Completeinattractive Walnut from A.C. mains.Improved type, 120 -watt output E. M. Delafield ;" Towers and Sheep -bells," Cabinet with threeMullardValves,Moving - Coil at .52110/0. Send for our comprehensive listof aprogramme aboutFonthill,byNorah Speaker, Batteries and Accumulator.New, in SI-teakers, Resistances and other components. - sealed cartons, £3 17s. 6d. (List,61 gns.) WARD, 46,Farringdon Street,London,E.C.4. Richardson ;and " Countrymen Afield," to Tele. HOLborn 9703. celebrate the birthday of Richard Jefferies. LUCILLE. 5 -Valve American Midget Sets. Com- A new series entitled " Crowded Moments " plete with 5 Valves. Moving -CoilSpeaker. Ready BANKRUPT BARGAINS.List free.Large stock cf for use on any mains 100/250 volts A.C./D.C. Long receivers, including all -wave valves, components, etc. was introduced and comprised visits to some andMedium Waves, 83 15s. Od,New, insealed -Butlin, 6, StanfordAvenue,Brighton. important centres by a commentator, who cartons. describedthescenes andhisimpressions. RECORD CHANGERS.-GarrardModelR.G.4, plays EXPERIMENTER'S OPPORTUNITY. Parcels con- automatically and changes eighttO-in.or12 -in. tainingWireless Components, 40/-valuefor5/6. These " Moments " have ranged from Plymouth Records of any kind. New, in sealedCarton,£6. Carriage 1/-.Taylor's Radio_House, Macaulay Street, Hoe on a Saturday night to the Tramways GRAMOPHONE MOTORS. - COLLARDElectric Huddersfield. Centre,Bristol. A broadcast was taken Radiogram Units. For A.C. or D.C. Mains. 100/250 from the Royal Show at Ashton Park, Bristol. volts. Fully Auto Stop complete with Pick-ups. 3;- each-American valves,all popular types. 90 - Can be used on any mains.Brand new, insealed day guarantee.Full range in stock, National Union, Programmes made with theaidof the cartons, .57/6 each. Hytron, Triad, Metal, Glass and M.G.Send for lists. mobile recording unit included " May Games," COLLARO Electric Radiogram Units, complete with each-Mullard, Cossor, Mazda, Marconi, Osrain a composite picture of the traditional customs valves forD.C, receivers; all perfect. 90 -day Pick-up and fully Auto Stop, for A.C, Mainsonly, guarantee,State type. Send Cash or C.O.D. for bringing in summer in the West ;Barn- 37/6 each. COLLARO Single Spring Gramophone Motors with RADIOGRAPHIC, LTD., 66, Osborne Street, Glasgow, stapleGreatFair ; and Sherborne Pack 10 -in. turntables complete with all accessories, 11/-. C.t. Monday Fair. Double Spring Motors with 12 -in. turntable,15/.. A THOUSAND BARGAINS COLLARO Battery RadiogramUnits.Comprising MAINS TRANSFORMERS, M.C. SPEAKERS, MAIN3 Wales DoubleSpring Motor andPick-up mounted on VALVES, SHORT-WAVE GEAR, CABINETS, Ete. plate withallaccessories,35/-each. All Collaro Plans were completed during the year for the Motors are Brand New in Sealed Cartons. conversion into studios of the Public Assistance SPEAKERS. - CELESTION Soundex permanent PREMIER SUPPLY STORES Offices, Alexandra Road, Swansea.The new magnet, 10/.. TELSEN permanent magnet, with 20-22, HIGH STREET, CLAPHAM, S.W.4. accommodation includes a large music studio, I0-rgtio Transformers to suit anyReceiver,12/6. SEND 3d. STAMP FOR CATALOGUE. a talks studio,a dramatic studio, and an Telsen Loud -SpeakerUnits,2/6. AllBrand New and Boxed, MISCELLANEOUS effects studio, in addition to offices. COILS.-Telsen Iron Core, W.349 (Midget size), 4/-. Twenty-five plays were broadcast up to Type W.478 (Twin), 9/- pair.Type W.477 (triple), GRAMOPHONE Attachments forRadio,electric November,1936, andofthese,the most 16/- per set.Type W.476 (triple Superhet, Selector motors,.25/- ;Pick-ups, 9/6; Portable Gramophones, outstanding were " Flood," by W. Evan and Oscillator), 16/- per set. All ganged coils com- 12/- ;spring motors, 4/6, dozen, 36/-,100, 512/ 10, Williams, a realistic drama of the pit ;and plete on base with switch.Telsen I.F. Transformer 1,000, £100 ; walnut pedestal Anexagram, 85. Sound - Coils. 110 kc., 5/-. Telsen Dual Range Coils, with boxes,tonearms,horns,cabinets,needles, gears, " Y Llaw Gudd," a murder play adapted by aerial series condenser incorporated, type W.76,,4/-. springs,accessoriescheapest. Lowerpricesfor John Ellis Williams from the novel by E. TelsenAerial condensers with shorting switch, 2/-. . quantity buyers.Catalogues free.-Regentpop, 120, Morgan Humphreys. All Telsen components Brand New in sealed cartons. Old Street, London, E.C.I. AMERICAN VALVES.A full range of valves for all The chief outside broadcast in the period American receivers, 6/- each. FLeeeLieuTE, complete with stand 12/6, postage underreviewwasa programmeentitled MISCELLANEOUS BARGAINS.-All brand new in -.100-w. bulbs 5,6.Headphones 2,11, postage 4d. " Old King Cole."This. took the form of a original sealed cartons : Telsen A.C./D.C. Multimeters, -Jameson's Radio Ltd., 2.2.,NelsonStreet, S.E.10. microphone tour of the Wyndham Colliery, test anything radio or electrical, 8/6.Telsen 2 -range A.G. MOTORS. Allvoltages, from14/9. Lists Ogmore Vale. Voltmeters, ; 3 -range meters, including milliamps., free. RepairSpecialists.-EASCO,P.W.Dept., 4/, . Ace (P.O.) Microphones, with transformer ready 18, Brixton Road, S.W.9. Nineteen religious services in the English for use with any receiver, 4/6 ;36 assorted Tru-ohm language were broadcast during 1936, and Resistances,twatt, colour -coded and marked, .36 BESTERTH Patent Earthing System is best 464...toriv- twenty-four religious services in the Welsh on card, 6/- per card. Bell Transformers, 200/250 or short waves.For particulars write John Huln:es volts input, 3,5 and 8 volts output, 3/6 ;Morse & Sons., 16, Isleworth Drive, Chorley, language.There were nineteen appeals. Signal Units, incorporating buzzer, tapper and flash TheWelshInterludeswhichbrought with internationalcode,completewithbatteries DETECTION. New theory, system, circuits, book, leading figures in Welsh life to the microphone and bulb, 3/9 each. Varley Square Peak Coils, post trio, 111.-D'Arcy Ford. 6anily Street, Exeter: were continued. Other seriesin the pro- B.P.5, 2/-; Marconi V.24 and Q type valves (useful for short-wave experiments), 1/6 ; glass insulators, grammes of Welsh talks included " Discover- 4b1. Lightweight headphones, double pole, 4,000 ohms SITUATIONS VACANT each ear piece, 3/- pair.A.G. Trickle Chargers, for 2,' ing Walea" and" For Welsh Farmers." POST OFFICE ENGINEERING.Excellent openings Two discussions have been outstanding- 4 and 6 volts, 17/6. for young men age 18-23.Start 83.13.0. weekly at " The Drift of Employment," a joint dis- CAR and RADIO BATTERY CHARGERS, incor- age 18.Nu experience required. FREE details of (the Welsh porating Westinghouse Metal Rectifier.This Charger exams. from N.I.E. (Dept. 606), Staple Inn Buildings, cussion with Midland Regional willenable you to keep your car batteriesfully High Holborn, W.C.t. speakerswere Lady Rhys Williamsand charged, for use on 2, 6 and 12 volts, 45/- each. Arthur Jenkins,M.P.),and " Conflictor REGENTONE ELIMINATORS, A.C., 200/250 volts, G.P.O. ENGINEERING DEPT. (noexperience Conciliation in the Coalfield." type W.5a, with trickle charger, 37/6. required). Commencing £3.13.0 per week. Age 18-23. SOUTHERN RADIO. Branches at 271-275, High Road Excellent prospects. Free details of Entrance Exam. The News Service in the Welsh language from continuedasanightlyserviceuntilthe Willesden Green, N.W.1 ;46, Lisle Street, London, B.I.E.T. (Dept. 568), 17-19, Stratford Place, London, W.C.2. Allmailordersto323,EustonRoad, autumn of1936,when a new bi-weekly London, N.W.I. W.1. service was inaugurated. SOUTHERN RADIO, 323,Euston Road, London, WHEN replying to advertisements, please besureto (Tobe continued.) N.W.1 (Near Warren St. Tube). 'Phone : Euston 3775. mention " Popular Wireless."Thanks I POPULAR WIRELESS February 13th, 1937.

CAN YOU BEAT 0 0

`We had four people last night to hear my brother on the radio so naturally the L.T. - batteryhadto let us down

' Go on.... Why don't you get an Exide " Hycap" Battery ? Lasts much longer. Besides, it warns you in time when it needsrecharging.'

BATTERIES FOR RADIO `Still keep going when the rest have stopped'

EXIDE 'HYCAP' BATTERIES(High Capacity L.T. Batteries) The battery for modern multi -valve sets. It lasts longer on one charge. For small sets the best battery is the Exide D' Type. Both have the Exide Charge Indicator. Your dealer will teh you which to use.

Obtainable from all reputable dealers and Exide Service Stations. Exide Service Stances give service on every make of battery. - - Exide Batteries, Exide Works, Clifton Junction, near Manchester.Also at London, Manchester, Birmingham, Bristol, Glasgow, Dublin and Belfast.

Printed in England and published every Wednesday by the Proprietors, THE AMALGAMATED PRESS, -LTD., The Fleetway- blouse; Earringdon Street, London, E.C.4. Advertisement Offices:John Carpenter Rouse, John .Carpen: Street, London, E.C.4.Registered for tmuaraissiun- hv Canadian Magazine P9 A.Subscription hates: Inland and Canada, 17/4 per annum.Abroad (except Canada), per annum.Sole Agents for Australia and New-Lealand: Alessre.-Gordon & Ltd.and for South Africa:Central News Agency, Ltd.Saturday, February 13th, 1937. S.S.