| 摘 要： | A long-range broadcasting system may be considered as a system of speech transmission.Theprincipal parameters involved in this system are the average spectrum of speech,the function ofsignal pre-emphasis,the characteristics of electro-acoustic transformation and the attenuation forsound transmission in air.At present,the relations between these parameters and frequency usuallyare described by diagrams or quasi-empirical formulas.In most cases,the interrelations among theseparameters are complicated,and designing the broadcasting system are difficult.In this paper,onthe basis of theoretical derivations and experimental results of these parameters,the approximateanalytic formulas of the relation between these parameters and frequency are obtained by using themethod of curve fitting.It is convenient to design a broadcasting system by using these formulas.As an example,a design method of a broadcasting system for 8—10 km is introduced.
|
