[电] instantaneous frequeney-indicating receiver

shùn shí pín lǜ zhǐ shì jiē shōu jī ㄕㄨㄣˋ ㄕˊ ㄆㄧㄣˊ lv4 ㄓˇ ㄕˋ ㄐㄧㄝ ㄕㄡ ㄐㄧ