DROITWICH

Evening Post, Volume CXVIII, Issue 94, 18 October 1934, Page 23

DROITWICH

8.8.C.'S NEW^TATION

HIGH POWER/AND UP TO DATE

(F^ni-^'"Th^ Pflstls*' Representative.) :,:,.'. 'y LONDON, Soptembpr 7. • WK&t' is linown as Davontiy SXX: in. tho broadcasting world has provided the national programme service to tho, British .risles'for' lime years. Now it is tobC; ywithcirawn, and tho Daventry station " is" tq; 'be ' devoted exclusively to tho .short-jyave : Empire, service. Very, unostentatiously the 8.8.C. has been building, its' .new 150-kOowatt transmitting: staiion .near Droitwich, and the public'fijivo heard little about it. Having completed' it, however, they invited 500 pressmen and others to pay a visit of inspection yesterday. A special train carried., the party from London to Birmingham, and others joined at Birmingham. Droitwich Spa, famous for', its. brine .baths.and its brino wells,., is about , seventeon miles south-west of Birmingham. Tho new wireless station is a.mile outside the town in open country, the site being chosen so that there mil be the minimum of interference' with "local stations. : ' '' ■ ' '■ ■ '■ ' ' The new station will provide rather more than twice- the signal strength available from Daventry SXX to the whole of the British Isles, and last night listeners had their first experience of tuning in to this new and powerful station. Some apprehension has been felt as to whether many of the receivers now owned by the public will be detrimentally affected by the new service, but the 8.8.C. has given the assurance that this will not be the case. The; results of the reception, however, will doubtless be the subject of many thousands of letters. The Droitwich station has been designed as a dual-programme transmitting station, and in addition to the longe-wave transmitter it will, house the new Midland Eegional transmitter. 700 FT MASTS. The visitor cannot help being impressed with the two great masts rising 700 ft in height. The insulators at each end of the main cable seem a foot in length and quite unimportant, but we were told that each of them is 10ft long and a ton in weight. Such is the deception of height. Each mast is insulated on a concrete block, but when the lift up the centre, of the mast is put into use the mast may be earthed. Inside tho new building th,e ~very latest developments have been incorporated. 3?or instance, the power house generates alternating current instead of direct current. The. high-tension supply for.ltlie ' 150-kilpwatt long-wave transmitter, 30 amperes .'at 20,000 volts, is normally obtained from mercuryarc steel-tank rectifiers, and not from generators. The switch-gear controlling the various power supplies to both transmitters can be operated automatically from tile control table in the transmitter hall. In several other ways the new station differs in design from that of the four regional stations. POWER HOUSE. Fuel oil storage.,is provided...by two tanks'at the rear of the building, each having a capacity of 150 tons. This is ' Sufficient to enable the station to radiate-two programmes on full power for.a ip.eriod of three months. Outside are the -cooler for the Diesel engine circulating water and the silencer pit. In the power house there are four 750 b.h.p. six-cylinder Diesel generator sets. All four engines are mounted on a 900----ton reinforced concrete block lying on a pad of eorki-' This effectively isolated the vibration of the engines... The transmitter haN has a ground floor and a gallery. On the ground floor are Sail the motor generators for the two''transmitters, and the filament current''machines-for the long-wave transmitter, and the filament current generators, grid-bias generators, and H.T. generators for' the Midland Regional transmitter. In the gallery on the oiio sido are the five watercooled valves for : the long-wave transmitter, and on the- other sido will be ,Iho valves for the regional transmitter. Outside, iir tho grounds, is a concrete bath the size of a small swimming bath, the water of which is pumped over the pipes containing the distilled water circulating to cool the valves. Tho power control table is situated at one' end of the transmitter hall. On this are mounted the essential controls for both transmitters. Two engineers sit at the control tables regulating the various power supplies through the medium of the automatic switch-gear. Interlock circuits make it impossible to connect two machines to the same Ipad, or to make serious mistakes in switching operations. LANT>-MNE NETWORK. Then there are the control-rooms. The station, of course is connected to the simultaneous broadcasting land-line notwork by means of buried cables to Birmingham. : This network of private telephone lines, by the way, brings in about £80,000 a year to the Post Office, but .when it is remembered that a concert in. London costing. £1000 may bo relayed to all stations in the United Kingdom by means of these underground lines it will be seen the telephone service soon pays for itseliV Finally, the office block.of the Droitwich building is equipped' with offices for tho ongineer-in-chicf and his staff, a large messroom, ■ kitchen, quality cliecking-rooin, an oscillograph-room, vnlvo stores, and a studio for test and emergency use. Thus tlie 8.8.C. has incorporated in its now station all that is new and up to date in this. rapidly-developing science. It will be a year before it will bo possible to■ determine the exact performance of the -station in all typos of atmospheric conditions. The reception tests, however, have proved that the Droitwich signal is more than that of Daventry in all districts except those within a few miles of Daventry, and it is hoped to give a satisfactory service to nearly the whole of the British Isles. ...

Among those who visited the Station wero Mr. L. Macfarlane, a member of the New Zealand Broadcasting Board, and Mr. W. E. "Wilson, of Auckland.