> On Jul 14, 2016, at 4:15 AM, Andrew Rich via aprssig <aprssig at tapr.org> wrote: > > GPS is rs232 sense not TTL IIRC the garmin GPS18 manual claims that is the RS232F standard. The 18 has worked fine on the assortment of opentrackers and USB/rs232 adapters as well as the d700 I've used them on. -Jason kg4wsv