Packet progress...
My second NinoTNC is built. The parts came today from Mouser in a huge box. I need to adjust the case a little to make it fit nicely but now I have this one I can go mobile and see how access to GB7RVB is. So far, no-one has connected (and yes, the antenna is still in the loft!)
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I did find a TNC program for the Mac called KISSet which works fine once I remembered to put my callsign in! I wondered why it was sending data and GB7RVB's TNC was receiving - no callsign. Twit. It worked fine after that.