The RLM at first planned to use a radio control system with the V-1 for precision attacks, but the government decided instead to use the missile against London. Some flying bombs were equipped with a basic radio transmitter operating in the range of 340–450 kHz. Once over the channel, the radio would be switched on by the vane counter, and a 400-foot aerial deployed. A coded Morse signal, unique to each V1 site, transmitted the route, and impact zone once the radio stopped transmitting.