Telautograph, in which two different frequencies are used to transmit each of the two components of the movement of the transmitter pen, one for forward and backward movement in each component direction
DE603444C
Telautograph in which different frequencies are used to transmit each of the two components of the transmitter pen movement
GB354749A
Improvements in apparatus for distant electrical control
GB355653A
Improvements in remote control for radio apparatus
GB353414A
Improvements in radio beacon and printing apparatus
