On Sun, Sep 26, 2010 at 4:30 PM, mike bryce <prosolar at sssnet.com> wrote: > I wonder if the external amp keying requirement comes out of the aux connector? > Aux Connector specs from the brochure: ACC Din Connector: 8 PIN DIN Connector - Line In, Line Out, Aux PTT, Ext Key, Clock/Data/Enable, Ground 73, Barry N1EU