WIRELESS NOTES

New Zealand Times, Volume L, Issue 11655, 20 October 1923, Page 9

WIRELESS NOTES

By

RADIO.

DEVELOPMENTS Jv\cry week-is seeing :*omc fresh development in ladio. and its value to .the community in inoieasing daily. It has become a valuable auxiliary to the mercantile marine, and .saves large .sums of money by going to the aid of fogbound’ and bringing them to harbour. It is being applied to aviation in a man•ie:- that there seems every likelihood of the pilotless aeroplane becoming an accomplished fact. Or' the experiments maao in this direction the world does not hear very much, but they aro proceeding nevertheless, as is proved by Irtish and startling developments recorded from time to time PIONEERING WORK The theory of wireless control was laughed at when fi:st mentioned, but shijv, ar? handled by this method almost every day now Wireless is in its infancy, and although the idea of running inotcr-ears by wireless may .sound somewhat fantastic at present, thought is being given to tlie subject, and the day may yet come when it will be possible to stick up vour aerial and .start off on the road, taking power from the ether that is in the air. Neither is the day far distant when wireless is going to bo of great domestic value. quite apart from ihe entertainment it affords now in the* wav of picking up broadcasted concerts anti general news. THE AMATEUR HELPS The amateur enthusiast gets to work end instils hi* modest home-made set for his own amusement, but he is rendering a service all the time, for he is helping to pioneer, one of the greatest advances ever made in adapting a scientific discovery (o the beneficent purpose of making life the more worth living. DON’T OVERDO IT Those persons who want . sets with anyihing from four to eight valves, may be interested *o know that the set used by tlie Admiralty at Whitehall during the war was only a two-valve detector amplifier iLK) It will thus be seen that a complicated ?.et is not required to receive signals from long distances. A two-valve set carefully designed and adjusted will receive nearly all stations in Australasia and as far as California. UP AT BROOKLYN A Brooklyn er.thisiast entertained a party at his residence on Tuesday evening by listening-in to Christchurch, and they had the pleasure of hearing an excellent concert, which cuiue in splendicly through the small horn without icsorting to the larger loud speaker. Wanganui was also picked up, but the atmospheric conditions were not too good, although weather and market reports were taken. Probably some of them felt that they knew all about the weather Some of the -amateurs did, especially those who had not taken too much pains in fixing their aerials Quito a few found their masts on the ground on Wednesday morning. Even in the early stages ! it is worth while bearing in mind that Jif a thing is worth doing at all it is • worth doing well. Meanwhile “Radicy^ I is engaged in working out the cost of fixing up ;\ modest home-made receiving :;ct. using as much material ns he possesses in order to reduce the cost. Indications are that it will cost between £2 and .£3, ]>ut something will be said an the subject when it has been tried tmt. 2AUSE OF DISTORTION Two or three times correspondents have referred to distortion. It is a most 'iificult business at times to track down .he cause of any distortion of speech or music that may arise in the ret. In many cases it is due to slight oscillation in one of flic valves, which is not easy to control. In a set that is working properly there should be hardly any found in the receivers when nnv of the grid connections are touched with a wot finger, but this state of affairs is ideal, and one can seldom attain it. IS till, the clicks should bo vo:.v slight ones indeed when the test is made, and if oscillation is absent they lack the characteristic Diarp soun l with which one soon becomes familiar. Oscillation on the highfrequency side is usually due to iho transformers. The more sharply they can bo tuned the more liable they aro to cause it. WHAT HAPPENED \S hat happens is this: Grid circuit and plate circuit are tuned to precisely the same wave length; then impulses from ; tne latter pass to the former owing to | the capacity that exists within the valve, I producing a feed-back or reaction effect which .gives rise to oscillation, 'i’he use 0? anti-capacity valves may cause a considerable improvement in this lospeet, especially on short wave lengths whose j high-frequencies make this automatic reaction effect particularly liable to occur. A FAULTY LEAK The other possible lurking place is in the detector valve itself. Here it is caused usually by a grid-leak of the wrong value, or bv the fact that the leak is connected to L.T. negative. Whatever kind of circuit is used in the set one should always test out the grid-leak connections to see which will give the better results. Sometimes the effect of conneding the leak to L.T. positive is remarkable. A faulty leak may be responsible for all kinds of hissings and cracklings in Hie receivers, and if one or two stages of L.F. amplification are used these may become so loud as almost to drown signals. WIDENING THE SCOPE A project was recently put forward at ; Manchester for the broadcasting of the extra-mural lectures under the University extension .scheme. These lectures were so popular in the ordinary way that the authorities could not accommodate all those wishing to hoar them, and it is therefore proposed to widen the audience by using the broad-costing station. The Broad-casting Company appears to be having an experience common to people who endeavour to give public services at a Jow cost. This experience consists of much destructive criticism from all kinds of people. SOME USEFUL HINTS The following mo a few useful hints to amateurs who are making up their own sets or effect adjustments io the sets they have: Tlie cotton covering used for insulating wire nearly always contains moisture, which causes leakage and therefore a loss of signal strength. All tuning coils wound with this wire should be thoroughly dried and dipped into a bath of hot paraffin ware. This wiJl exclude all moisture and make the set mere efficient . To produce o mellow tone in the headphones. the following tip proves very Mjccessfnl. Carefully remove the original diaphragm from the ’phones and cut a piece of mica of the same size. Across the centre of the mica lay a small, perfectly flat, piece of tin, and use this far the now diaphragm. 'This idea should not he tried when the signaL are not fairly loud. 'The following is an effective and simple way of testing the efficiency of.telephones. Having placed the ’phones on the head i put tlm mci.tl connection of one lead between Ihe teeth, holding the otli-w in f}..; > hand by the flex. Take a piece of melai - -such a< a pair of steel scissors-—and gently i"b the fine tag. (Pi doing this a M-raping -mud will bo heard in the ■pjmnes U thc\ are fI.K. To ‘-older two wires or i terminal and

u no iii .Tin awkward, position -dip a piece of ordinary silver paper in powdered resin and wrap it round the job to be soldered. Then touch it with a lighted match, or a red-hot wire if the match might injure anything near. 'The silver paper will meet and stick to the metal. A sound connection is the result. military wireless Lhe wireless section of the Signal Corps in Wellington carried out some useful work on Saturday last. A mobile unit, under I.ieut. IT S. Wheeler, equipped with a 30 uati continuous wave portable transmitting ami receiving set, left (he signal hut at 3 p.m. by motor and proceeded to various points in the suburbs, whore the installation was set up and put into communication with signal headquarters, wireless station. After messages had been exchanged the set was dismantled, removed to another suburb, and the operation repeated. GOOD WORK A very creditable performance was recorded in one case. The unit was disnianticd, packed up. motored a distance of half a mile, re-erected ancl communication reopen'd inside eleven minutes. Ihe working distance was approximately two to three miles, but this range could bo increased up to vine hundred miles without, reduction in efficiency. A feature of the wire’ess equipment is the use of small copper gauze ‘‘mats” four feet by two feet in place of an earth. Eiarth mitts prevent less of time in setting up tlie station, «vs they act on the capacity principle and may be spread cut on dry grmnd w?th good radiation effect. The set is very compact, the whole equipment and five men being transported in one car. CHRISTCHURCH, WELLINGTON, AUCKLAND The siation at headquarters is a very .efficient one, and is capable of oommunieatirg with lord Coutley, Auckland, and Badio-Awnnui in daylight, with a signal strength sufficient for the exchange of traffic at normal morse rates, it is'hoped that the installation at Corps .Signal, Christchurch, will be ready to co-operate "ith Wellington and Auckland Signal Corps in about a week. THE MOBILE UNIT The following formed the personnel of the mobile unit:—Lieut. Wheeler, CorI poral Boyle. Sappers Morrison, Emeus, j and Driver W. J. Creed,, while Jlead--1 quarters was operated by Secoml-Lieut. ; Ash bridge, assisted by Sapper Mitchell. | GOOD FOR AUCKLAND i Mr Francis G. Miller, station 5.8. F., Murray Buildings, Australia, reports having heard New Zealand station 7.Y.A., i which is the call sign of the Auckland i Radio Service Station. This was heard jen two consecutive nights when specially , listening tor New Zeeland signals, and | the voice of the announcer was dearly i audible, but fading vns bad at times. jTho concert v.aj exceptionally good. 'n.Z.—AUSSIE TESTS . I Eleven transmitters and thirtv-five receivers entered for the New Zeafand-Aus-Aialia tests. A number of the competitors weic -successful. in getting their transmission through, or in receiving the Neu .Zealand messages at there stations v Inch do not possess transmitting sets. ! Covering long distances on low power has • its research value, and radio engineers ; will certainly delve into tlie question a-s 'to whether they arc getting the most efficient result.-, from the large power impiit employed at the commercial stations. bompnratuvely, they ought to bo able to hold conversations right mind tlie earth, in dear and fullv audible torfes. WIRELESS NEWS In reference to the news which is wirdos-ed to shipping, a gentleman closely inteiestiug in the matter told “Radio” that tlie New Zealand nous was mutilated. 'I his was probably due to the fact that: it was sent from Sydney instead of New Zealand, owing to the fact that the charge in .New Zealand was three time*s as high a> that in Sydney. The wireless proprietors find that to pay the New Zealand rates would not make the “Wirej*** .'\e\vs” a commercial proposition, j Dominion news i* cabled to Sydney, and I cut tailed reports are tent out to the i ships from there. ! jWIRELESS PILOTING j A British scientist, states the “Aorojnaut’cal Digest,” predicts that, wireless i will be used ip the near future for directing ships at sea, train and trolley services, Gallic control on the road, fleets of battleships, and aircraft. “It. will be possible,” lit: deelaies, “to direct, jtbe pat>i of everything moving on tlie I surface of tlie earth, not oven excepting j human beings, by wireless” Tho initial I slop » tho harnessing of this little 1 known and potent force has been the establishment of a wireless lighthouse on 1 Inehkeilh Island, in the Firth of Fort!), j By means of this “lighthouse” ships can 1 be directed through the dangerous clian- | nels of the Firth by wireless, so that there is no possibility of their, running ashore or being wrecked on even the j darkest night or in tlie densest fogs. jWIRELESS DIRECTION OF SHIPS Steps are being taken by the Board ot Trade, in conjunction with tho British | Meter dogicid Office, to internationalise jtho wireless direction of ships at sea. |Tlmre is lying in the Fort of London a skip that has been specially fitted with powerful winders receiving sets to give demonstrations of this new method of navigation in all the principal ports of the world. Setting out from London, tins missionary ship will sail for China, via the Mcclitoranean, Indian Ocean, and the Strait*;, and thence on to North a ml Smith America, and back across the Atlantic to Europe and South Africa, giving demonstrations at every big port en route A HIGH AMBITION Tiie most, ambitious effort, turnover, will be a cross-Atlantic flight, which is to be made late in the summer. Tlie machine will carry both pilot ami- observer, but their attention win ]>o confined to Ihe actual flying side. Sotting out from Newfoundland, for tho first €OO miles of its flight, the aeroplane will be directed by the Glace Bay wireless stain ns. Then it will go‘picked up and [navigated by a wireless ‘‘lightship,” (raising in mid-ocean, to a point whore conlrol will be transmitted to Ongar. the ' big operating station in England. Tho whole 2000 miles of flight will be directed by wireless NEWS FROM MOTUEKA Mr \V. K. Lanr. of .Motuoka, writes :~ “In reply to yours of tlie Sth insb, 1 may still state that l am receiving the American broadcasting station with my reflex sot iu.-ri as regular as before (every night). Now that [ have got used to tho wave length of the station 1 am receiving them much louder than before. K.JI.d. and KI T. can be heard all over the room quite loud on the loud speaker. 'J'h ere aro quite a number of persons who have heard these L'alifornian stations all over the room, and some of them are Mr ('obb. care Turnbull and •tones. Ltd., Wellington; Mr Guy Laurance, care E. ,1. Ilyams, Ltd., Wellington: Mr Fox. care B:n\vn Bro-.., jewellers, Motuoka; Mr Warner, rare Motuoka •Mar” office; .Mr F. A. Knapp, manager garage, Motuoka; Mr A. Sti 1 well, care btihull and to., Motuoka. These arc

only a few who can verify my statements. “1 have just received a new Galifornian station, just the same strength as the others, but will not publish my report of same until L receive full particulars from it. l have already received his call. K.H.J. is the loudest station received by me. In the room with the loud speaker, with all windows and doors closed, the music can be heard 50ft. outside quite distinctly; so you will see they are received strong. Mr Cobb heard it very loud when lie was at our place, and if you ask him he will tell you. 1 think it surprised him. “The local broadcasting slat ions come in 0.K., but I do not get much music from the Wellington broadcasters, and when Ido they are very weak. The Dominion Radio Co. come in much louder, and can be heard on loud speaker. The best station I receive in New Zealand is 4 Y.A., Dunedin. This station is very strong, and music and speech is as clear as a bell. This station, with window open, can be heard quite distinct 300 yards from loud speaker; so you will see it is very strong. 1 can get Wanganui, 4 A.A., 3 A.A., 3 A.C., 4* Y.U. (considering power very weak 4 Y. 0.), and 1 Y.A. These are the only stations that I receive worth speaking about, although they are not very strong. I have only listened-in for Australian Amateurs once, and got one station with music and speech very loud and clear. I intend to listen-in and receive more before 1 publish .same. There are about three stations in New Zealand which I receive music and speech, but have not been lucky enough to got code calls. I only bother about the Californian, Australian and 4 Y.A. New Zealand stations for music. As soon as the stations using only small power increase their power no doubt a wonderful difference will take place.” REPLIES TO CORRESPONDENTS H. Jones, Carterton,—A bepanite rheostat. should be used for the detector valve, although one can be used for the two amplifier valves, whose temperature is not as critical as that of I the detector. As the price of rheo- 1 stats are .so reasonable, we would suggest you use on each valve, no you can use either* one stage or both stages of the amplifier. “X.Y.L.”—On all standard vab.es the locking pin on the side is between the plate and grid terminals. “Radio,” New Plymouth.—On W.D. 11 valves the big lieg is the plate. Diagouonally opposite is the grid leg. “New Chum,” Masterton.— Filament adjustment on detector valves is important and very apt to be critical. Hence the vernier Rheostat or bradleystat is required on the detector valves, but not on the amplifier valves. There is the usual talk of summer static. Your long distance receiving records may be effected somewhat, but the splendid local and nearby stations will be quite O.K. if you will' remember: (1) There is no danger involved in static; (-) loose coupling is desirable; (3) whatever tends towards selectivity is especially useful; (4) considerable indue hince in circuit tends to decrease any static disturbance; (5) give special attendance to your head receivers. Use the best “Gertrude,” Gossville. —No. Gertrude, you should, not pour condensed milk into your condenser to sweeten up the music, and extra wave-lengths cannot be procured at the local hairdresser’s. PERSONAL “Mark One,” Masterton, writes as follows;—“I have a loose coupler (very loose) and a bed spring, two long nails, and a piece of coal. What else do I need to hear 4YA? Can I tic the lightning switch to a lightning rod? We i have no tats for a cats whisker, will one | off a dog do ?” Mr T. H. Nixon, for some time licensee of the Imperial Hotel, Wanganui, has purchased Air Harold Brown’s interest in tho Rutland Hotel, Wanganui, and takes possession on October 23th. Mr A. J. Harris, of Croydon, England, who is interested in wireless, is now in Wellington. He says the programmes broadcasted daily from London. Paris, and Manchester are “really fine,” and contain vocal and instrumental items of some of the world’s famous singers and musicians.. BROADCASTERS’ CONCERT An excellent concert was rendered by the Wellington Broadcasters, Ltd., last Wednesday night. The following artists contributed, and their items were much appreciated by a large number of lis-teners-in: —Song, “Hail Calarionia,” Mrs Scott Allan, Mrs McMillan at the piano; song, “They Say,” Miss H. Perry, Miss Lemon ut piano; recitation, Miss M Dix, “Yes, Papa”; pianoforte selection, Mrs McMillan; song, “When You Come Home,” Miss V. Mueller, Miss Ijomon at piano; song, Mrs Scott-Allan, Mis McMillan at piano; Bong, “Peace Cross,” Miss H. Perry, Miss Lemon at piano; levitation, Miss M. Dix, “McGinty”; song, “Sorter Miss you/’ Miss V.. Mueller, Miss Lemon at piano; special icquerT, “Lcch Loraontr.” NEXT WEEK’S PROGRAMME The following is the Wellington Broadcasters, Ltd. programme for next week : Monday, October 22nd, Mr Flank Andrews and Miss Florence Penny, L.A.B who scored such a big .success with the Annette Kellerman Company throughout New Zealand and Australia, have signified tliMr intention of appearing at tho Wellington Broadcasters’ Station on Ford Building, Wellington, on Monday evening, October 22nd. These, two well-k»o4i*n artists will give varied items and will give the whole concert from 8 to 10 p.m. Listeners-in are assured of a concert, which has never before been approached at any broadcasting station in Australasia. Next Friday, “Miss Wellington,” a young amateur pianiste, will play n selected programme of dance music, including jazz (fox trot and one-step), waltz and other items. The special children’s programme, which lias put on at 7 o’clock on Monday. Wednesday and Friday evenings, bos lieon greatly appreciated. When approached bv < “Radio,” Wellington Broadcasters readily fell in with the suggestion. The idea has now 1 ecn taken up elsewhere. Imitation is the sinceresl form of flattery MUSIC FROM CANADA A telegram received yesterday from Air Lane, Motuoka, says: “Receiving music from Canaria on reflex set. Letter following.” Details will be given next week.