SYDNEY BRIDGE BROADCAST

Hawke's Bay Tribune, Volume XXII, Issue 106, 19 April 1932, Page 5

SYDNEY BRIDGE BROADCAST

The broadcasting of the Sydney Harbour bridge opening ceremony was notable for trie fact that one microphone was sufficient for all the broadcasting stations in Australia, as well as a battery of public address loudspeakers, talkie films, and gramaphone records. The Bridge Celebrations Committee arranged that in the hands of Amalgamated Wireless should be left the control of the broadcast with the particular intention of avoiding the multiplcity of microphones, which is usually a feature of a gathering of such importance. It was the task of the engineers of A.W.A. to devise means to ensure a circuit from which all the broadcasting stations interested could take a “split” without reacting upon each other. A single microphone served for all the speakers at the official ceremony. The output passed into a two-stage amplifier placed by A.W.A. under the dais, and irom that point the service was split into 18 channels, each controlled by a Budiotron UX. 112 A valve. To each of these services a signal was given at a certain predetermined level of volume, which had been agreed upon by consultation between A.W.A. and the engineers of the broadcasting stations. Bach station was thus in a position to amplify the service at a point behind the dais or to pass it on to its own studios for further control. Each station had a separate microphone at the rear of the dais, so that the announcers of the several stations could add special matter of their own choice up.on the main service and fade the latter in or out as they wished. The talkie companies were given an elevated position on the other side of the road, the wires to their stands running across the road in pipes which were covered with asphalt. In addition to the single microphone for the principal speakers, another microphone w-as situated in the corner of the dais for the Governor-, w’ho announced the various speakers. A third microphone was placed in a corner for the official announcer, who described the proceedings. One of the “splits” served the public address system installed by A.W.A., a special amplifier being used, which gave a 60watt undistorted output obtained from four Badiotron UV. 211 power valves in push-pull circuit. These valves were fed from a pair of Badiotron UX. 245 valves in push-pull preceded by a single Badiotron UY. 227. The high tension for this amplifier was obtained by a pair of Badiotron UX. 866 mercury vapour rectifiers. From the power amplifier 25 A.W.A. public address loud-speakers were fed. These speakers were carried on electric light standards on the Bradfield highway and on Observatory Hill. As these speakers were dynamic they required field excitation. To accomplish this all the field windings were connected in series, direct current being obtained from an amplifier, and this service broken down with carbon filament lamps. In Hyde Park A.W.A. also established a battery of six loud-speak-ers on top of the company’s public address vehicle. These were operated from an amplficr, and this service kept the crowd advised while they were waiting to move oil. A Badiola 55E served to receive the speeches through 2FC. The whole arrangement, passed off excellently, both in respect of the broadcasting, the talkies, and the public address speakers. PROGRAMMES FOR TO-NIGHT. IYA Auckland.—At the W.E.A. session the subject will be, “W. H. Davies—the Tramp Poet,” the speaker being the Rev W Jellie. A half-hcui of the latest light re cord ngi- will precede a Shakespearean

programme to be given by J. M Clark and nis company, Mr l.iark will rtxite Robert Ingersoll’s famous appreciation of Shakespeare During the evening various scenei both hum.-i-ejs and dramatic will 1 c acted. Mr Clark will be supported by Althea P.rker, Allan McSkimming. Gaston Mer-’ale and IC. M. Newhng , 2YA Wellington.—The next instalment of the Music Lovers’ Competition will be broadcast at 7.35 p.m. A varied programme of recordings has been selected. 3YA Christchurch—The Christchurch Salon Orchestra, under Francis Bate, will proide the evening programme. 4YA Dunedin.—At 7.40, Mr W. F. Forrester, president cf tho Dunedin R.S.A., speaks about “Poppy Day.” A programme of Russian music will be broadcast in the evening. All the most popular of the great Russian

composers will be represented in tho vocal and instrumental numbers, which will be given by local artists and by means o {recordings. Gwenda Burt will sing four songs, including “The Red Sarafan” (by Whishaw), while the orchestral programme given under the direction of Mon B. L. de Rose, includes Tschaikowsky’s “Coprice Italienne,” Rubinstein’s “Feranios” suite, and selections irom Rimsky-Korsakoff, Rachmaninoff, and Moussorgsky.