October, 1929 - QST


A Modern 50-kw. Broadcast Station

We acknowledge the friendly cooperation given by Mr. Walter G. Cowles of the Travelers Broadcasting Service and
his technical staff in preparation of this article.

By James J. Lamb, Technical Editor

Although most of us are more or less familiar with the generalities of design of modern amateur and commercial radio transmitters, few of us realize that the amateur and commercial fields have so much in common and that the present trend in amateur technical development is paralleling closely the progress in commercial design and practice. Attainment of that frequency stability,

broadcast transmitter is rated in kilowatts while the amateur is restricted to watts, the modern high-power broadcast transmitter contains numerous features of design which can be applied profitably in amateur practice. QST presents WTIC's new 50-kw. transmitter, therefore, not only because it marks a milestone in modern radio development but also because it contains so many features whose application can be of

Everything is within view of the operator. The transmitter proper comprises the panels forming the left side of the right-angle. The rectifier and power-control panel are on the right. The panel at the extreme left carries the UX-806 rectifier units for the crystal-oscillator-amplifier, buffer amplifier, and modulator on the panel at its right. The 5-kw. amplifier is at the left of the open gate and the 50-kw. stage is at its right. The box on the operator's desk contains the push-button control for the entire transmitter.

maximum distortionless modulation, and reliable transmission considered desirable in amateur radio of today, becomes an absolute necessity in contemporaneous highly-competitive commercial broadcasting. It is not surprising, therefore, to find that the modern commercial transmitter not only contains those features which characterize modern amateur transmitter design but in addition utilizes them to a much greater degree in obtaining that type of performance which we amateurs are finding desirable and which broadcasters are finding necessary. Although the modern commercial designer considers frequency shift in terms of tens-of-cycles-per-second while the amateur thinks in hundreds, and the modern

inestimable value to the further development of amateur transmitter technique.

When one goes about choosing the site for a radio station representing the investment of some hundreds of thousands of dollars, he does not pick the first likely looking spot he comes upon and build his station there. Few indeed are the amateurs who have even the opportunity of choosing the location of their station, let alone determining whether or not it is the Will-o'-the-Wisp "good location" dreamed of. In the selection of the site for WTIC's transmitter lucky chance in choosing a location was not resorted to.
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