Broadcasting the "Old Vic."
How a Remarkable Experiment Was Carried Out.
In the hurly-burly of the day's work there is little time for the ordinary individual to develop his powers of imagination.
But even the unimaginative individual felt something of the wizardry of wireless transmission when, on the evening of Saturday, November 23rd, a novel and remarkable experiment by the engineers of the B.B.C. achieved complete success. On that occasion, the first set of the opera La Traviata was relayed by wireless from the "Old Vic" Theatre in London to 2LO, and then broadcast simultaneously from London, Manchester, and Glasgow.
A Difficult Problem.
The usual way of connecting up a theatre with the headquarters of the B.B.C., at Savoy Hill, is by using a private wire direct, between those two places. In the ease of the "Old Vic" Theatre, it was found necessary to have a direct line from Waterloo Bridge, but the Post Office were unable to supply this, as all the existing lines are permanently engaged. They offered us, therefore, the alternative of a line seven or eight miles long, passing through three different exchanges. As most of this circuit would have been underground, and not very suitable for the transmission of music, our engineers were confronted with the problem of overcoming this difficulty. Captain A. G. D. West, Assistant Chief Engineer of the B.B.C., set to work upon the problem.
An ordinary type of microphone was played on the stage just in front of the conductor of the orchestra. The currents passing through this were amplified by an apparatus at the back of the stage, and brought out to sufficient strength to operate the transmitter. This apparatus was connected to the transmitter by on ordinary lead-covered cable about forty yards long. The transmitter was situated in a room on the top storey of the Royal Victoria Tavern, next door to the theatre.
To Prevent Distortion.
On the roof had been erected a single-wind aerial about twenty feet high and twenty-five feet long. The power used in the transmitter was thirty watts, and a special mint about the theatre amplifier and the transmitter was that great precautions had to be token against any possible form of distortion, so that the music received at 2, Savoy Hill, should be quite pure and undistorted. The operation of the apparatus at the theatre end was made more or less automatic without the need for control.
On the roof at 2, Savoy Hill, the aerial, a single wire about fifty feet long and six fret high, received the signal from the theatre transmitter, amplified them up to sufficient strength, and then put the music on to a line connecting the studio with Marconi House, where it was then transmitted in the usual way. The amplified signals were transferred to the Post Office lines and for simultaneous broadcasting in the customary manner. A Special receiver had been designed so as to receive the music from the theatre without any interference from 2LO, which is about 200 yards away, across the Strand. It is now possible, therefore, to connect up the "Old Vic" with any or all of the stations of the B.B.C.
This work is in the public domain in the United States because it was published before January 1, 1929.
This work may be in the public domain in countries and areas with longer native copyright terms that apply the rule of the shorter term to foreign works.
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