NEW MICROPHONE

Radio Record, Volume I, Issue 3, 5 August 1927, Unnumbered Page

NEW MICROPHONE

-"CONDENSER" TYPE FOR 2YA GOOD FOR MASSED EFFECTS A new type of microphone, known as the ‘‘condenser,’’ has lately been placed on the market, and a number have’ been ordered from England by the Radio Broadcasting Com: pany for use at 2YA, Welling ton. The condenser micro: phone has already been used at 3YA, Christchurch, with most Satisfactory results. It is pos: sible one of these microphones will shortly be sent up from Christchurch to 2YA, Welling> ton, for use in the big studio in the capital city until the microphones on order arrive from England. EXCELLENT FOR BANDS. Condenser microphones constitute ome of the most important features*in the new equipments for broadcast stations. Viewed as oue of the recent triumphs in radio engineering, the new ‘anikes’? are of inestimable importance in the broadcasting of large programmes. ; The condenser type of speech unit permits the mixing of «6s many as four microphones, distributed «t various places in a studio or concert hall, to carry one programme. For example, the concert of a 100-piece band, sections of which would be practically lost in a single microplione output, obtains better transmission through the multiple arrangement. PERFECT BLENDING. With such a scattered microphone output, the blending is made harmonious and of the desired balance by the control-room operator. It is left to the judgment of the announcer to determine how many microphones are required to obtain perfect transmission of a programme, BETTER THAN CARBON TYPE. The advantage, which the condenser microphone has over its rival instrument, the carbon microphone, is largely a matter of tone quality. The conenser ‘‘mike’ brings out a more rounded, full-depth tone, The annoying hiss and ground noise often attending the use of carbon units is also overcome. ‘The level ‘or relative loudness of speech ontpnt from the condenser microphone combination is approximately the same as with the old. style, An interesting sidelight on the new multiple output system ig the fact that,

the control-room operator may cut out any microphone which is cansing trouble, and mix in a new one without the change being detected by the radio andience LOOKS LIKE A CAMERA. In appearance the condenser microphone resembles a somewhat elongated box camera. Finished in black crystallised lacquer, the niicrophone box is mounted on a gunmetal pedestal, which may be adjusted to any desired height. A lj-inch aperture in the face of the box admits sound to the diaphragm. The condenser microphone is equipped with the necessary circuit to carry tite voltage applicd to it. One stage of amplification is used with a specially developed vacunm valve and output transformer, ‘Ihe battery veltage for the "inike’? unit and the amplifier valve is fed to the instrument in ‘a thin, flexible cable. ‘his may be of any length, saisfactory tests having been made with a 900-feet run.