[App_rpt] radio interface question

Mark Hagler markhagler at gmail.com
Thu Oct 25 03:07:40 EDT 2007

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.


Mark Hagler

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