The Gang of Five

The first and most unusual of the group is the radio controlled Radicon Robot. The robot is a huge 38cms, dwarfing most other robots. The paintwork is a plain hammered grey finish. This is easily the first radio controlled robot. The electronics are, by modern standards primitive. A transmitter generates a high voltage pulse which triggers a light, a spark and a turning action in the robot; it is not a steerable robot. The electronics are unreliable, hard to repair and capable of giving a generous shock if handled improperly. An article on the robot appeared in Popular Mechanics in 1958. The massive ear antennas obviously owe much to Robby, but here one serves a real function as an antenna. It's woth noting that the arm construction is more complex than the rest of the group: there's an elbow panel holding together the upper and lower arm as opposed to the more simple two piece pressing of the later robots.

Here's H. I Gosses excellent explanation of the electronics:

The Radicon works with one of the oldest forms of radiotransmission, i.e. the Coherer tube. This is a length of glass tubing, sometimes vacuum, with nickel-filings inside. The electrical resistance of this tube is normally high. (=no current) If this coherer is struck by a "radio wave", the filings become "Coherent" and conduct electricity. In case of the Radicon the radio wave is made by a spark-coil, that causes high voltage sparks. Hence the thick, and necessary!, insulation on the transmitters antenna. So spark> coherer becomes conductive > current to the galvanometer-relay in the chest, (The round thing behind the window. This is a coil which, with very little current starts to turn and so closes two contacts, that will allow larger current to pass) > The Galvanometer-relay switches a much larger current> > this current makes the "Choices-motor" work, which then takes one step in a fixed order.These are:Set the wheels to Left turn, Straight ahead, Right turn or locomotion motor "off".So it receives only ONE signal, which makes it move one step in it's repertory. At the end of it's operation the "Choices-motor" hits the Coherer, and, as little Johnny is no longer pressing the transmitter, the conductivity of the coherer is disrupted and the "Choices-motor" stops. The toy hence goes on in that "mode" 'till the "Choices-motor" is used again. The wierdest part of this arrangement is, sadly, hidden from view. This is the Coherer that is suspended on little steelsprings as,what looks like, a trampoline. This contraption is, after each command, violently beaten by a spring loaded,bludgeon, that is cocked back by the "Choices-motor". This system is used by all the Radicon toys. i.e. the tank, the bus etc.Only difference is that in the robot, the relay has a transparent side, so you can see the action. In the others everything is hidden. If you do not believe me, take your Radicon apart, or use for ex. a piezo-electric gas-lighter. It is a perfect transmitter to every Radicon! Reversely: take the genuine Radicon transmitter to any delicate electronic device, (your Computor for ex.) and see the devastating effect of the EMS it causes.

(For further in-depth speculation about the Radicon Robt see the second Robot Talk archive)

German collector Gernot provided the following remarkable picture from the Masudaya archive. It shows what is clearly a plan for a lithoed Radicon.

Thanks also to Gernot for this wiring diagram, again, straight from the Masudaya vaults and dated 1957. It could possibly be part of the patent application.