Application to Radio of Wire Transmission Engineering

This article points o u t t h a t radio a n d wire c o m m u n i c a t i o n systems are subject, f u n d a m e n t a l l y , to the same general requirements, a n d its purpose is to develop for radio, points of view which are familiar to wire transmission engineers. T h e transmission characteristics over a wide range of distances are compared. For short distances the comparison is favorable to wires. A l t h o u g h over great distances, the a t t e n u a t i o n of electric waves, guided by wires, m a y be greater t h a n the unguided waves of radio, it is pointed out t h a t at the present time intermediate amplifiers can be more economically applied in wire transmission than in radio to boost the message energy. E c o n o m y of transmission requires the h a n d l i n g of messages at as low an energy level as possible a n d , as the a u t h o r points o u t , wire transmission satisfies this requirement m u c h better t h a n radio. Referring to the transcontinental line with radio extensions, which was used recently to talk from C a t a l i n a Island in the Pacific Ocean to a ship in the A t l a n t i c Ocean, it is stated t h a t had all of the necessary energy been introduced at one end of the circuit, there being no intermediate amplification, the total power required would have been 1.8 x 10?3 kilowatts, an a m o u n t unavailable in the world. In the actual system, distributing the amplification along the transmission line, the power required sums up to something less t h a n 1 kilowatt.