waisted female drawings of 1890s fashion artist Charles  Gibson. Its shape allowed the operator to hold it between the legs  while cranking it the necessary 80 RPM to produce enough electricity  to operate. It could be set to automatically send an SOS signal or  switched to send Morse Code signals. Early models transmitted only  on 500kHz, later models also could transmit on 8280kHz (later  modified to 8364kHz). It was notorious for being tough to crank.