On Mar 18, 2016 9:15 AM, "dwight" <dkelvey at hotmail.com> wrote: > > Also, you see most applications using 1702s instead of 4001 > or 4308. I've never seen a 4308 in the wild. I've seen one 4308 in the wild: in a later generation ARC RT-485A NAV/COM radio. The earlier ones just use four 4001s. Kyle