RE: Some early digital proportional history
In meeting Jerry Pullen, Doug got a job over with him at JPL, mainly to get access to those new NPN transistors they had at the time. Inspired by Pullen's analog proportional rig, Speng got the digital pulse width figured, he set it to 1-2 msec, 1.5 being neutral, it "just worked out" to quote Doug. I remember bugging him with those stupid questions when I worked with him at World Of Robots in Laguna Hill with some of the old Orbit gang. He was the one engineer who could hand you a hand drawn schematic, you could prototype it, and it would work perfectly, amazing that guy!
But the encoder/decoder/ modulation scheme was the missing link back then. Even though the Digicon was good in theory, test, and initial flight testing, it wasn't bullet proof. Hoover ironed out that part of it, but the servo was his nemisis, each guy had his own row to hoe. That break allowed Eliot and Krause enough time to do the Digimite. Nobody could really make any money at this point due to cost, and the novelty factors involved. Bonner had a cheap stick, which it was, but he sold alot of them to everyone, that was more profitable than the Digimite systems.
The later Larson/Novak RS systems had several generations, the first using the orange 4-RS SY servos and Cannon connectors. Later units had D&R servos, and the famouse "gum pack" receiver. Hobie Hawks came with a special RS Systems 2-Channel single stick radio with a dual servo brick to unitize the airborne installation. Novak sold to a guy whose name escapes me now, but they finally closed up and then it was sold to someone back east. They were in Orange and Santa Ana Ca. proir to that.