NOTES AND COMMENTS

Radio Record, Volume I, Issue 34, 9 March 1928, Page 8

NOTES AND COMMENTS

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Accumulator terminals collect | substances which in spite of cleaning always return, This is due to the electrolyte, so that it should always be wiped away from the top of the battery, and the terminals given a regular cleaning now ald ayain. When soldering always place a piece of paper on the baseboard to catch any drops of solder that might otherwise mar the board. Heat so great that steel metals evaporate as reatlily as alcohol in a still is uow capable of being generated in a new high-frequency vacuum furnace, which utilises the same electric currents ns those employed in radio communication. Curreut of a frequency correspon-ding-to a wayelength of ten thousand inetres is sent through a coil inside a vacuum bell, creating a heavy oscillating maguetic field. If a metal is placed Witlnn the coil so that it absorbs most of this energy, the frenzied atoms generate such frictional heat in responding to the changing magnetic field that the metal is liquefied and gasified in less time than it will take the reader to read this paragraph. When drilling a panel, particular care should be taken, as the look of the panel will either make or break the finish of your set. In order that the drill does not slip, the places for the holes should first be marked with a_ centre punch. A drill smaller than the hole desired should be used first, in order that tearing of the panel does not cccur, Where possible, 2 template should be used so that the correct size holes can be cut, and each component correctly spaced. When an earth is connected to an outside tap or water pipe, it will be necessary, unless the joint be well soldered aud insulated, to inspect it frequently, as corrosion will otherwise set in, and cause bad contact. Insulation tape, being waterproof, is probably the best insulation to use on au outside connecion. But it is always best to solder your earth wire to the water-pipe. A correspondent writes to the Sydney "Wireless Weekly’? :-‘ Your correspondents who find Sunday church services such a distasteful subject should rememver that if their requests were granted, and what one lady refers to as ‘Bible nanging and ‘canting’ were cut out of the Sunday programmes, fully 95 per cent. of the Sabbath listening public ind many outback homes, who have no means of, wearing church service, would ne deprived of Divine worship and very njoyable choral singing and also the yeautiful organ accompaniments." The Roman Catholic Church in New South Wales has engaged the B class poadcasting station 2UIt, Sydnéy, for -wo hours on three nights a week. 2UE operates on 293 metres with a power of 50 watts on ‘I'uesday, Thursday and Sunday evenings. The station is operated by Radio House, 617 George Street, Sydney. , When soldering leads in your set, the | ‘ron should never be allowed to get red not, ‘his will burn away the tinning, yesides being far too hot for practical | ise. ‘To tin your iron again will take ime, so always give it due attention, 1ever forgetting to wipe it on an old ‘lean rag immediately it leaves its source of heat. An Australian radio writer says: "Imnossible advertisements have a great teal to do with the supposition that vireless transmission and reception | tave improved. The firms of to-day, yarticularly those in America, seem to lave a strain of exaggeration about hem. The over-statements of some of he American firms would lead one to relieve that radio has reached the end of its tether as far as advancement is ‘oncerned, yet Marconi, the actual orignal instigator---or rather, I should say, liscoverer of the characteristics. of wireess waves-is most emphatic about the idvancement of these subjects, and strongly ayers that there is still plenty of room for improvement."* Scotland Yard authorities have ow lecided to make the fullest possible use of wireless in their efforts to curb the utivities of criminals, and the fast notor-cars which haye hx n_ specially \ssigned to the flying squad have been quipped with wircless sending and reeiving apparatus. A course of instruc‘ion in the Morse code has also been started, and batches of detectives at~ end the wireless room at police headjuarters to receive lessons im the myseries of dots and dashes. By soaking a small strip of cardboard in Indian ink and then clamping each end to a terminal, a good grid leak can he made. By gradually cutting off a little from each side, the best thickness for the proper resistance may easily be found, & In Australia a wireless license cntitles the licensee to use wireless in the premises occupied by him at the address mentioned in his license, One license will cover any number of sets installed wn the same premises for the use of the licensee, liis family, or his servants. It bould be noted, however, that. if any ther person oceupying a portion of thie wane house wider a separate tenancy lesires to install apparatus, he miist take ont a separate license.

Radio valves do not contain a perfect yacuum. ‘Ihe ordinary detector is estimated to hold about thirteen trillion miolecules of air. An absolutely perfect vacunm has never been. produced. In the highest vacuum thus far attained, less than one ten-billionth of the air originally in the glass bulb remained after the. exhaust pump had done its best work.~ ; A simple chemical polarity indicator consisting of a piece of litmus paper moistened in a solution of salt and water is a simple means of determining the positive or negative leads of a battery. By touching the two leads to the litmus paper, one lead will turn from red to dark lavender This will be the negative lead. Litmus is a purple dye, sensitive to acids. The liner Jervis Bay, of the Australian Commonwealth Line of steamers, which was fitted with a short-wave installation about two years ago, has beeil m eonstant connnunication with the local coastal stations throughont each voyage to London and return, and a direet commercial service is being maintained for the benefit of passengers and their friends on shore. Last October advice having been received that a commercial short-wave station hal heen opened for ship communication at Burnham, England, communication was established and a service has since been maintained by the vessel direct with Iingland throughout the vovage, Sydney to Tondon and return. . In drilling bakelite, even at ordinary speeds, it is a much better olicy to use "high speed" drills, as these will not he damaged by the overheating which is usually experienced. They cost a little more, but their increased life will more than make up for their first cost.

Perhaps one of the most effective ways in which religious services via radio touch the heart ij through their imusic. The thousands of letters that pour into the larger American stations show clearly that weil-knowu hymns mean a great deal to large uumbers. Interviewed in New York in Jannary, Marconi was asked: "Do yvu believe that television will enter the homes on as large a scale as radio concerts at the present time?" He replied: ‘‘Yes, television will be seen in -homes throughout the ‘land, but I do not know how soon." A London radio writer, in an article in the New Yori. ‘Radin News," says: "There is not as yet any decided tendency he:e to call a iadio valve a ‘tube,’ but duet will coine in good time. We must not huccle the imagination of stolid materialists who cannot recognise in a pear-shaped bulb auy special like ness to a tubular object. When you sav ‘tube’ to a Britisher he thinks of a sewer pipe or the glass tuge of the chemical laboratory, or the subway, which used to be called the ‘twopeusty tube’ because the fare was twopence, any distance. He calls a valve a valve because somebody called a valve a valve; and he has always called a valve «w valye, because it is a valve." A new technical compilation of forninlas and tables for the calculation of serial capacity has recently been prepared by the United States Bnrean of Standards. It includes formulas for calculating the capacity of almost every and of aerial-the single, horizontal (‘T) wire, single-wire inverted L, horizontal ‘‘cage,’"’ etc., etc. There are also valculations of capacity of lead-in wires and tables for aerial calculations. New Zealanders who desire to purchase this publication should wire to the Government Bureau .of Standards, Washington, U.S.A., for Burean of Standards Letter-Circular 224.

Marconi was asked in New York recently: ‘In your opinion, will the present broadcast band of 550 to 200 metres ever be changed to short waves, thns necessitating the scrapping of present equipment?"? He replied: "I can see a field for short waves, but they will play their most important role in international exchange of programmes; that is, for long-distance broadcasting. However, I believe the wave-band now used for broadcasting entertainment is well adapted for that use, and I can see no benefit to be gained for the broadcasting stations to operate on channels below 100 metres unless they desire to he heard in foreign countries. As there is no license fee for broadcast listeners in the United States, the listener being a "beggar" cannot be a "chooser," and has to accept what is handed out by the broadcast statious. In the Iebruary issue of the New York "Radio News" a listener writes :-‘I would suggest broadcasting a plan asking every radio listener to contribfite a dollar (4s. 2d.)° towatds establishing a fund to cover the cost to stations and entertainers of ole or more super-programmes, of, say, not mere than two hours’ duration. If the stations did not wish to father the idea it could be sponsored by your publication or by a committee of listeners. A big hook-up could be arranged that would nullify any charge of favouritism between stations and, if I am anywhere near correct in my prognostications, the furtherance of this plan would lead to a permanent high-class form of reception which millions of listeners would be glad to pay for.’’ A system of voluntary contributions was tried in New Zealand before the Broadcasting Company was formed. Resultfailure. An American radio writer says of -radio-vision-‘If the public would care for a rather poor picture we could give ‘it to them to-day, but I think it advisable to move forward nearer perfection before we begin to broadcast pictures, We might be able now to send out pictures comparable in quality to the music radiated in 1920-therefore, you see, we are not yet ready to broadcast perfect pictures. The television problem to-day is to simplify our ap--paratus. It must be made practical aud economical so that it can be used in the home at no more cost than broadcast receivers are to-day. I should say we still have a long way to go." So there! The electrons, tiny specks of negative electricity, so small that even the most powerful microscope cannot detect them, give the radio valve its ability to promote progress in radio. One scientist estimates that if a drop of water, which includes a vast number of electrons, because of the hydrogen and oxygen within it, was magnified to the size of the earth, each electron magnified in proportion would be about as large as a grain of sand. Listeners who are troubled by loud howls from their sets when the last stage of audio frequency. is brought into operation, although the set functions well when only one stage is used, may be interested to learn that it has been found in a numlber of cases that seldom does the fault lie in the recciver itself, Usnally it is caused by run down "B" batteries. Substitution of new batteries is the only means of determining if this is so in any particular instance. The greater the number of valves employed in the set, the more likely it

, Mr. Max Howden, thé prominent Meitbourue amateur trausmitter, writing in the Melbourne ‘‘Listener-in,’’ says :- "A Japanese station is now working regularly on an approximate wavelength of 39 metres, but IL have not yet heard its call sign and whereabouts announced. Ljistemimmg one evening a man and a woman kept up a continuous nionotone (which I took to be their national music) for over half an hour. ‘hey were going when 1 switched on, and still going 30 minutes later, when I switched off. It is rather a novelty to listen to these foreign programmes, but it soon wears off in fayour of the local programmes."’ Captain Richard H. Ranger, inventor of the Ranger system of plioto-radio transmission, in a demonstration and talk before a session of the third annual convention of the Institute of Radio Engineers recently in New York, showed how jets of hot and cold air, playing on a sensitised screen, combine to effect one of the latest and most effective methods of recording photographs transmitted from a distance over radio waves. Captain Ranger, who is an engineer of the Radio Corporation of America, transmitted and _ received photographs and facsimiles the length of the stage in the auditorium, utilising the ‘‘proto-radio-scope,"? an instrument which makes use of the airjet principle, to record the pictures in @ greatly enlarged state. Captain Ranger said that the photo-radio-scope and ac- | conipanying apparatus has recently been applied to the facsimile transmission. of advertisements, messages, and holiday greeting cards, as wcll as for photographs. Accidental reversing of the polarity of the leads from the set to the ‘A’ battery is often the cause of a set’s failure. Should these leads be accidentally reversed, great loss of volume usually resvlts. Indeed, in some cases, the set will cease functioning entirely. Remember ‘like’? goes to "like." Phe HWattery clip matked (plus), should be fustened to the battery post, or ternénal imarked (plus), and the ‘clip matked (minus) to that imarked (niinus). The same rule of connection applies to the "B" battery. Shonld the "B" battcry leads become reversed, however, the set will go absolutely dead, and no sonnd whatever will be heard from if. Next time vou shake hands with Thomas A. Edison (says the Chicago ‘Radio Divest’’) take a good look at the right side of his face. That is the side his genius is indicated. Note the shaggy belligerent eyebrow that will not behave, note the sharp penetrating quality of the eye, the general aggtessiveness and push, while the other side of his face is genial and rather docile These are facts narrated bv John EK. Garabrant, who-has made 1560 photographs of the wizard, and alwavs photographs taker Grom the right side. At the third annual convention of the U.S.A. Institute of Radio Engineers at New York recently the first public announcement of a new radio receiving circuit, which permits the reception of the full ‘‘side-bands" from a _ broadcast station’s signals without accompanying loss of selectivity, was made by Dr. Frederick K. Vreeland, radio experimenter, when he delivered his paper on the new set before the institute’s evening session. ‘The results are accomplished by using a system of balanced resistance, called a "band selector," inserted in the radio frequen. cy staves of a set, The "A" battery should really never cause much trouble through being ron down, but these things do happet; and at times the "A" battery is the unsuspected cause of a set’s failure to work. Keep a hydrometer handy and test your battery at intervals, and you will not have trouble from this source. Owing to lack of support, broadcasting of European music has ceased in Shanghai. An effort is being made to obtain voluntary subscriptions to keep broadcasting going, but the inauguraters have so far met with little success, It is estimated that there are over a thousand European-owned sets in Shanghai, but only 130 have joined the China Broadcasting Assncia-. tion. Chinese music and items are on the air during the greater part of the day, hut very few Tfuropeans appreciate Chinese music. The yolun-. tary subscription plan proved an utter washout in New Zealand. -_

t Fifty broadcasting stations and three short-wave transmitters in the United States were expected to broadcast to the world the addresses of President Cool- | idge and President Machado at the opening session of the Sixth Pan-A\meri-can Congress recently in Havana, Cuba. It was planned to enable the whole nation to hear the speeches from Cuba through the regular broadcast transmitters, while the short-wave installations, 2XAD of the General Electric Company at Schenectady and &XK of the Westinghouse Electric and Manufacting Company at Pittsburgh, were to relay the voices of the American and Cuban Presidents to foreign lands. Dr. A. N. Goldsmith, chief broadcast engineer of the Radio Corporation of America, is planning an extended experimental cifort to communicate with Mars. If there are intelligent inhabit-_ ants on the planet he believes they will be able to comprehend a dot and dash code if there is sufficient repctition. ‘The plan of attempted communication would involve the use of a huge beam transmitter or a bank of searchilights,