Hello all I'm new to the group and just starting to assemble pieces to make a working app_rpt repeater system. To get up and running quickly I was thinking of using two mobile radios + a duplexer (a setup like the Motorola GR300 repeater, minus the crappy controller). When I look at all of the newer radios I own they all have a 6-pin DIN jack on the back often labeled "DATA" as it's intended to connect to a TNC for packet radio. A further look shows that the pins in this jack are all the right ones (COR, PTT, audio in, and two types of audio-out). I was wondering if anybody has attempted to hack together a simple working duplex system by just tapping into two mobile radios via this 6-pin connector? There's two types of audio available on that connector as far as I can tell, one suitable for 1200bps packet and the other for 9600. It looks like the "1200" pin carries de-emphasized audio, and the 9600 carries non-de-emphasized audio (discrimator direct output). As far as I can tell either one of these would work with the radio interface cards available. Thanks, Mark Hagler W7WMH