WIRELESS NOTES

Evening Star, Issue 18333, 21 July 1923, Page 11

WIRELESS NOTES

[By Electron.]

A SUPER-SENSITIVE DX RECEIVER. Tho latest ‘ Radio News ’ contains a very interesting article by Mr J. H. Dixon, at VMG, Apia, Samoa. Mr Dixon says: “ Using only two valves, I am getting concerts every evening from America, 5,000 miles away, and from Hawaii, 2,240 miles away, and this means good speech and music". Our time is throe and a-half hours behind America, which means that part of the concert is received in daylight here. The same concerts can be received on one valve when static sleeps, but not so that they may he enjoyed, and only after much patient tuning. My aerial is a single seven strand, 80ft long, 50ft high, suspended between two convenient trees. The concerts were received about six months ago, tho circuit used being the Reiuarty, to wliich were added three stages of radio and one stage of audio amplification. The results with this receiver were quite good, but timing was difficult, and it was" replaced later by tho present adaptation of the Armstrong super regenerative. To date I have heard KHJ, KFI, KUY, KUO, KLP, KWH, KPO, KGU„ KDYX, and KDAF. I have pages of log on American stations. I have already given proof to J : he editor of good reception of the Christmas and New Tear concerts from KHU.” Spider web coils are used for Hie tuning elements in Mr Dixon’s circuit, and a C3Ol and V 24 valve used for No. 1 and No. 2 respectively. The apparatus used includes three spider web coils, four .001 mfd variable condensers, two mica fixed condensers, one each 250, 1,250, and 1,500 JIC coils, two rheostats, one 45-volt C battery, one 6-voJt A battery, and one B battery not less than 100 volts.

The individual parts should all stand on glass plates, and rubber shoes should bo worn when tuning in. No. 18 rubber and braid covered wire, is used, cotton covered wire being useless for connecting up. Tho layout of the parts is important, and tuning requires careful attention. Mr Dixon slate.? that it requires an experienced operator to adjust this circuit, and that there is little chance of a beginner being able to operate, it successfully.

AUSTRALIAN AMATEUR STATIONS. There, are quite a number of amateur and experimental stations transmitting in Sydney at present. Among these are 2CM, "2IX, 2LI, 2OS. 2GR, 2KC, 2UW. 2XX, 2ZA, 2,1 M, 288, 2DK, 2EP, and 2MB. Some of these stations have boon hoard in New Zealand. NEW BROADCASTING STATIONS.

Tho Radio Society of Christchurch has erected an aerial on top of Robert Francis Building, High street. Two 32ft Oregon masts have been put up, with a span of 53ft. A 15-watt set will be used, and the society is awaiting a permit to commence broadcasting. The Wanganui Radio Society has commenced transmitting experiments, and before long will bo working on a regular schedule.

Mr L. W. Field, of Wilkins and Field (Nelson), is erecting two 90ft masts in preparation for broadcasting on fifteen watts. The station is expected to bo ready in a fortnight's time, and it is intended to send out concerts on Wednesday and Saturday evenings. Tho work of changing over from fifteen watts to 250 waits at tho Wellington station is occupying a little longer than was at first anticipated. The 250-watt set may now not be in operation until next week.

NEW ZEALAND AMATEURS. Tho few Now Zealand l amateurs who nro transmitting aro obtaining excellent results. Air Bell, Sling Valley, has been picked up by Air Spencer, Raetihi, transmitting to Air Orbed, Christchurch. Raelihi is about 500 miles from Shag Valley, ’ but the voice was quite -distinct. Ou Saturday, the 7th, he heard “This is Bel!; 1 j Palmerston speaking here.” His voice I sounded as if ho were standing about 6ft l or Bft away. Incidentally, he heard tho ’ 1 bet made of “ a bob'’ as to which of them ' ; would pick up the most American amateurs between 7 and 9 o’clock on Sunday evening. j 4YO. , I Tho transmissions from the Dunedin , | broadcasting station 4YO for the last few . j wee'ks have been very .successful, and have i ■ provided enjoyment for hundreds of crys- , tal sot owners who have made their own ■ sots since 4YO commenced-, as well as the . largo number of valve enthusiasts who now listen-in nightly. 11 has not taken tho Dunedin people long to realise that a crystal set will receive the programmes from,4YO . quite loudly and dearly with even tho i cheapest of apparatus, so that radio is within tho means of everyone, even the 'schoolboy with his few shillings a week pocket money being able to save up sufficient to purchase the necessary materials for a crystal receiver. The concerts from i 4YO are received regularly on crystal eels ! at Port Chalmers, Macamlrcw Bay, and Green Island; while at Atilton, nearly forty miles away, Iho concert last Saturday night was dear and perfect on a home-made crystal set, though, of course, ; not loud. The gramophone records were , very clear, while, the sporting results and 1 weather forecasts, as well at; tho nmiounce- | ments, wove heard loud enough to follow. 1 There is no other centre in Australasia I where this is possible, so that Dunedin residents can congratulate themselves on the fact that they have a. wireless service which is available to everyone. In addition to the high-power station here, we have two other stations—4YA j (British Electrical and Engineering Com- | pany) and the Otago Badio Association—--1 providing excellent programmes on a lower ’ i power available to all possessing valve i rets ; while tho owners of the more elabnj rate sets can tune-in to programmes from ' j other centres as well. For anyone who, through illness or other cause, is comI piled to .spend tho evenings indoors, (hero is no greater enjoyment than Hs-tcn-I ing-in to the nightly concerts, and there I are many old people who look forward | with eagerness to the evening programmes for their daily enjoyment, | GENERAL NEWS.

A Gisborne publican has installed a fine three-valve receiver in his lounge, together with a lonct speaker, for the entertainment of his guests; while a Palmerston North hostel is said to be similarly equipped. It is stated' that a wireless sermon has converted a man at a distance of 500 miles! Wo can foresee the time when the equipment of a broadcasting station will include a special preacher for radio enthusiasts. AMATEUR WIRELESS DIRECTORY. “ Electron ” is compiling a list of amateur receiving stations in Dunedin and suburbs, with particulars of the circuits and apparatus used and stations that have been heard. A map is also being printed showing tho location of stations, and l when completed will be available for all thoso desiring a copy. It is requested that amateurs forward particulars of location of their station, type of set, and stations heard to make this complete.