RE: Radicon R/C Bus circa late fifties
I'm sorry I got into this discussion much too late. However, the topic of Radicon vehicles is near and dear as I have a number of them and restore them as a hobby. They use a marconi spark-gap transmitter and receiver with a coherer. Primitive but very functional. They were indeed the first RC toy ever made, imported from Japan by Modern Toys, Inc. sometime around the 50's. For control, they used a set pattern of movement. Stop - forward - turn right - forward - turn left - forward - stop and then repeated. I received my first one for Christmas as a kid back in 1954 when I was 10. I've had a fascination for them ever since.
While I have a few of the busses, I am still looking for a Radicon Boat to restore. Alas, the ones on eBay are too pricey for my retired pocketbook.
The Radicon "Holy-grail" is the Radicon Robot. It uses the same system and control strategy as the bus and boat but is exceedingly rare and almost priceless.
I also have the similar Sonicon Busses. These were essentially the same bus body and chassis but the internals worked on sound. There was a "drum" inside with a needle balanced on it that our pick up vibrations from a whistle. The steering would rotate until a signal was received, then the bus would move forward in the direction the steering stopped in. There was a parabolic antenna mounted on the roof that rotated with the steering wheels and showed the direction the bus would move in when the whistle was blown.
If anyone has Radicon vehicles and needs advice, please email me.