FMVFT Frequency Modulated Voice Frequency Telegraph
FSVFT Frequency Shift Voice Frequency Telegraph
VFT Voice Frequency Telegraph
voice-frequency telegraph system
voice-frequency telegraph terminal
AM voice frequency carrier telegraph systme
VFCT Voice Frequency Carrier Telegraph
VFT Voice Frequency carrier telegraph Terminal
voice-frequency carrier telegraph
voice-frequency carrier telegraph equipment
voice-frequency carrier telegraph terminal
double Voice frequency signal
VFA Voice Frequency Amplifier
VFB Voice Frequency Generator
VFC Voice Frequency Cable
VFC Voice Frequency Carrier
VFC Voice Frequency Channel
VFCT Voice Frequency Carrier Terminal