Recommendation M.625, Annex I,4, collective B-mode. It shall consist of an F1B radio-frequency signal modulated with a frequency shift of ±85 Hz centered on the receive frequency (490 kHz, 518 kHz or 4209,5 kHz), 标准测试信号 (STS) 将是与ITU-R推荐M.625, Annex I, 4,集体B方式...