ACROSS THE WORLD

Dominion, Volume 12, Issue 5, 1 October 1918, Page 9

ACROSS THE WORLD

THE GREAT CARNARVON WIRELESS '.. \ ~ STATIONS-' ■■-■■■■

INTERESTING PARTICULARS.

The; receipt , of the news .last-week that it ..was possible'to send by wireless direct' to Australia ' Jms given tho public something-exceeding-ly interesting and momentous to think about. One may,, for cxnlriplo,-" ; bo sure that the n.ows, o'f the ; :-declafation of-peace-will-be tra-nsmittecl to the uttermost ends of the earth (or at-least those parts of the earth provided'with wireless plants and sensitive detectors), within a. second of tho. official announcement. Being 11 J hours ahead of Great Britain iir tinrej we s'hould hear tho good news quite eleven hours before peace has been signed (according to tho time records at Greenwich, if not actually), ■which will"' , bo a fine achievement for, wireless; Prior to tho receipt of last week's historic message littlo had been, -heard '61 the big Mar? .coni station at Carnarvon (north Wales), which'for fivo : years past lias been in touch day and niglit with-the big American station at New Jersey. The r.ew station, or stations—for there aro complete and distinct plants for sending and receiving—are situated just outside the 'confines of Carnarvon town (which until fnr into the Middle Ages was tho richest and busiest city in Wales). 'Tho!'transmitting section ■is situated a few miles east of Carnarvoiii, en the Cofn-du-Jlountnin, tho station building: being about '680 ft. above sea level. Tho -receiving section is at Towyn, one of the most pleasant seaside resorts in the north of Wales.

( ■ The' transmitting and .-receiving sections are separate to eiMble duplex jvireless telegraphy to bo effected, that is ' to say, to make, possible tho simultaneous reception from and .transiuission to America. . It is not usual to havo so largo a distance separating the two sections, but it, was necessary to do so in this cnsc.'o'wing to pertain geofiraphical features. In dupJcx working the receiving section must bq-plac-ed in a'certain deflnito direction with respect to tho transmitting section, find here the correct angle could not be obtained with a similar site at a nearer distance owing to the configuration of the country. There are four wires' connecting . the two stations, these being carried on the same poles as tho Po.st Office telegraph lines, The transmitting station consists of one large building measuring approximately 100 ft. by 83ft., which is divided into' three sections, known as the machinery hall, the annexe, nnd the extension. The main transmitting sets aro in ihmlieate, each set comprising a 300 K.V.A. single-phaso alternator, generating- at 1750 volts and 150 frequency, directly coupled to and driven by a f>oo b.hv.p. three-phase self-start-ing motor, suitable for' 440 volts and 50 frequency.' This,-in'turn,-is directly coupled to a-shunt-wound exciter giving 300 amperes at 40 volts; •-'There are ten tubular steel masts, each 46flft. in height; the lower half being 3ft. 6in. in diameter, and the upper half '2ft. 6in. -.The-lower half is built of quarter sections, or quadrants, each' 15ft. in lengthy and th'o upper half is built of semi-circular sections, fianh- ten feet in length. -Power is:supplied to the station by. means of an overhead'transmission line, which provides a •threephase supply at 10,000 volts. The power station,- belonging to the North Wales Power nnd Traction Company, is situated at Gwn.Dyli,' about .11$-miles distant. There.is a transformer 'station adjacent to the wireless station, where the voltage is reduced fron 10,000 to .440 volts, at which pressure it appears on- tho switchboard;

At the Towyn-Station : the recoivino; aerial is supported, by fi-vc masts, eaelv 300 ft. .high. These masts' are erected on .a. range of hills at-tho back of'the town, tho last most being 1400 ft. above sea level... A. balancing aerial is also erected, curried on 80ft. poles, the purpose of which isto balance out the offect of signals, transmitted from tho stations at Cefn-du, so that tho signals received across .the Atlantic-are rot in any way affected -by the signals from the transmitting station. at -Cnrnavon. Tho station is equipped with all the latest types-of. receiving apparatus, and the, operating bn'jlding hiis been. designed to accomniftdate sufßcient operators to deal with .a traffio of 100 words per minute duplex,