Early proportional—Don Brown’s QuadruplexBy Duane Wilson kingaltair1@outlook.comPhotos provided by the author You’re ready for another successful day at the flying field. When you move the transmitter sticks, the corresponding control surfaces move precisely and proportionally as you skillfully conclude your flight with a perfect landing—or at least that’s the plan.We take our current, relatively reliable radio systems for granted, but in the early days of RC, the flying experience wasn’t quite as certain. Our modeling forefathers had to make do with early equipment that bared little…