VFC Voice Frequency Cable

VFC Voice Frequency Channel

AM voice frequency carrier telegraph systme

VFCT Voice Frequency Carrier Telegraph

VFCT Voice Frequency Carrier Terminal

VFT Voice Frequency carrier telegraph Terminal

Voice Frequency carrier

voice-frequency carrier telegraph

voice-frequency carrier telegraph equipment

voice-frequency carrier telegraph terminal

voice-frequency carrier telegraphy

VFC Video Frequency Carrier

double Voice frequency signal

FMVFT Frequency Modulated Voice Frequency Telegraph

FSVFT Frequency Shift Voice Frequency Telegraph

VF Voice Frequency

VFA Voice Frequency Amplifier

VFB Voice Frequency Generator

VFD Voice Frequency Dialing