摘要
本文主要介绍了我国首次进行的大功率中波广播发射机间引起电离层交叉调制效应的实验情况及测量结果,并根据大量测量数据及对电离层反射点电场强度的计算,给出交叉调制百分数与反射点电场强度关系曲线,用以推算不同的反射点电场强度时的交叉调制干扰程度;同时对交叉调制对节目质量影响程度进行主观评价,以便找出节目受干扰的可容忍限度。本文提出了可以接受的最大交叉调制百分数的新建议值为8.9%,对CCIR建议书498—1附录1做了重要补充。
The test conditions and results of measurement of ionospheric cross—modulation between two high-power MF broadcast transmitters Conducted in china for the first time are described in this article. Curves indicating the relationship between the depth of cross-modulation (in%) and the calculated field strength at the point of reflection in the ionosphere are given on basis of the numerous measuring data and the calculation of the field strength, these curves may be used to calculate the field strength at the different points of reflection in the ionosphere and the extent of interference of cross—modulation may also be estimated. In the meantime ,subjective assessment of the quality of reception on sound broadcasting programme had been carried out so as to find out the acceptable limit of cross—modulation interference to the sound quality of programme. A new acceptable maximum percentage (8.9%) of cross—modulation has been provided in this paper. This is a important supplement to Annex 1 to Recommendation 498—1 ,CCIR.
出处
《电波科学学报》
EI
CSCD
1991年第4期10-16,共7页
Chinese Journal of Radio Science
