[电] resonant frequency of a crystal unit

jīng tǐ dān yuán de xié zhèn pín lǜ ㄐㄧㄥ ㄊㄧˇ ㄉㄢ ㄩㄢˊ ㄉㄜ˙ ㄒㄧㄝˊ ㄓㄣˋ ㄆㄧㄣˊ lv4