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- voice frequency telegraph link 音频电报线路
- VFT? Voice Frequency Telegraph? 音频电报?
- speech plus voice frequency telegraph 语音加话频电报
- frequency modulated voice frequency telegraph 调频制音频电报
- frequency shift voice frequency telegraph 移频音频电报
- voice frequency telegraph terminal 音频电报终端机
- amplitude modulated voice frequency telegraph 调幅制音频电报
- voice frequency telegraph bearer circuit 音频电报承载电路
- frequency modulation voice frequency telegraph 调频音频电报
- voice frequency telegraph system 音频电报系统
- frequency-modulated voice frequency telegraph 调频音频电报
- VFT? Voice Frequency carrier telegraph Terminal? 音频载波电报终端?
- Specifications of voice frequency telegraphic interface 电报音频接口技术要求
- voice frequency telegraph tones 音频电报单音
- Voice Frequency Telegraph Gear 音频电报装置
- voice frequency telegraph 音频电报
- VFT? Voice Frequency Transmission? 音频传输?
- VFO? Voice Frequency Oscillator? 音频振荡器?
- Voice Frequency Telegraph Group 音频电报组
- VFT Voice Frequency carrier telegraph Terminal 音频载波电报终端
