Military field telegraph, interpreting DC signals to buzzer 1,000 Hz tone.
US version of the British Fullerphone. Used by the US Army since 1930s and during WW II. Designated TG-5-B.
Using military field cable, allows up to 20 WPM (Words Per Minute) morse code communications for a range of more than 80 Km, even on wet cables.
Using two 1.5 Volts batteries (BU-30) and one 22.5 Volts Battery.
Weight: 3 Kg.
