Seventy-five years ago this month, the April 1948 issue of Radio News featured on its cover this radio-controlled sailboat, getting ready to sail the waters of Boston harbor.

The rudder was controlled by a DC motor, and the remote used two channels to set it to port or to starboard. Polarity was reversed to change direction of the rudder, and it was geared so that the full travel took about 15 seconds. The remote control transmitted on both 51 and 53 MHz, and the receiver circuit shown below featured two separate suprregenerative receivers, one for each channel.

The magazine reminded readers that an amateur radio operator’s license was required to operate the craft.