VK3ZPF-L who would have though it was so hard to get Echolink working

I have had a busy couple of weeks getting the VK3ZPF-L Echolink node working, and I’m still not finished.

When I pulled out the interface we used last year it had broken wires and was in need or a rebuild. It was a prototype from 2007 so I was not surprised it was in disrepair.

I took the prototype away to Sydney with me along with the circuit diagram or the RT85 control head. With these two things I drew out a circuit that should have worked first go. It was a copy of the prototype but with pin numbers assigned to the 26 way IDC connector.

It wasn’t until I built the circuit and was ready for testing that I learnt that the pin numbering on the IDC connector is unconventional.

By convention pin 1 on an IDC connector is next to the pin 1 indicator, a small triangle on the side of the body. Not with the RT85. They call the wire nearest the triangle pin 13 with pin 1 being furthest from the triangle.

This added another 2 nights to my construction as I reconfigured my board to adapt to this stupid IDC layout. I also had some minor problems with audio ground as well but that was easier to fix.

Once the controller was working I learnt that the RT85 has a 1 1/2 minute timer on the transmit. I din’t really just learn thi, I have know about it for ages but I hadn’t considered it in my design.

I added a small circuit called an ‘anti-time-out timer timer’. This timer injects a break in the Press To Talk, PTT, control every 55 seconds to reset the time-out timer.

Today I installed the node at the location were it will be for JOTA and tested the RF and audio paths on the EchoLink test server before leaving. No problems there. I got home and was unable to connect from the Internet to VK3ZPF-L. I needrd to make some changes to the router settings. Again, no surprise there but something I had overlooked.

After I made these changes I could connect.

But that was 3 hours ago and now I can’t connect at all. I don’t know why, but I can’t get at it via the Internet input.

I can’t get RF to the site so I can’t try that but we will try tomorrow on the way to Gilwell Park and make sure we can get in via RF.

Once at Gilwell Park we will point a Uda antenna back toward the node.


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