In 1971, at age 14, I had a Heath DX20 (from a swap meet) and a Hallicrafters SX111 (from an SK). I wonder which of the controls on a K3 I would have been able to figure out back then? :) That's about the time I first dreamed about designing my own kits. I even tried one: a digital tach. But those SN7490s were just too expensive.... 73, Wayne N6KR