Ultra-Short-Wave Propagation: Mobile Urban Transmission Characteristics

' I ^ H I S paper is a sequel to an earlier paper, "Ultra-Short-Wave Propagation," 1 which dealt mainly with transmission across open country. In the present paper the research has been extended to include transmission within a built-up region. Additional problems of transmission within urban areas t h a t result from man-made interferences, such as the noise produced by automobile ignition systems, have been investigated. A specially equipped motor car was used as a mobile laboratory for most of this work both because of its convenience as a means of obtaining transmission data and because of the importance of mobile communication itself. This paper describes general characteristics and quantitative measurements of the received signal on 34.6 megacycles. Transmission * Published in Electrical Engineering, January, 1935. J. C. Schelleng, C. R. Burrows and E. B. Ferrell, "Ultra-Short-Wave Propagation, Proc. I. R. E., Vol. 21, pp. 427-463, March, 1933 and Bell Sys. Tech. Jour., Vol. 12, pp. 125-161, April, 1933. 253 1