Very nice! I haven't seen one of those Bonner stick ones since - oooh - around 1968!
You are still missing the very first one, though! It was a 3+1 system, using Bonner sticks, and remarkably similar to the F&M 3+1 system. I think that (like the F&M), it also used Bonner Digimite servos. The case was also F&M blue!
A quick history lesson!
Around 1967 (give or take a year!), pylon racing started to become popular in the USA again. It had fallen a bit by the wayside, but interest picked up with a new class of "Goodyear" racers, which had to be scale replicas of full size Goodyear racers (Shoestrings, Cosmic Winds, DeNight Specials, etc). They weren't required to be exact replicas, but close enough to fool a knowledgeable spectator. Power had to be supplied by an "off-the-shelf" 40 - no special racing engines allowed!
At the time, most proportional radios were big and bulky, and were a tight squeeze in a 40 size racing model! So, Orbit introduced an analogue 3+1 system, closely followed by F&M with a digital 3+1.
These were basic 3 channel systems, but had 4 servos. The rudder servo only worked when the throttle was not fully open. As soon as full throttle was reached, the rudder servo centered, and stayed that way until the throttle was reduced.
The idea was that as the rudder was only used during take-off and landing - and given that these were racers, they really didn't need 100% throttle on take-off - the rudder would only function during take-off and landing, and during the race, flying would be by "bank and yank"!
It meant that the receivers could be made significantly smaller and lighter than the full blown sets, and would be easier to install in the smaller models.
Within a couple of years, technology had moved on and the gains were no longer significant. 3+1 sets died the death. But for a brief period they were popular, not only for being smaller and lighter, but also cheaper than their "big brother" sets.
Here endeth the lesson!
--
Pete
