Motivation
A few years ago I’ve setup an echolink – RF bridge with the Kenwood TM-D710. With this I could listen and talk to an echolink node of No Agenda from Adam Curry. It’s quite an awesome thing to be able to walk in and around the house with my handy talky and be able to listen and talk to people on the other side of the world! When activity on that node minimised I cleaned up the setup. Biggest disadvantage I found was the need of a always-on-pc.
The concept of a local Echolink-RF bridge to use a HT to talk into a echolink node stayed in my mind. When I was preparing for our holiday to Denmark, the original idea was to bring a echolink node with me so I could talk from the beach to our local chat frequency. This would be done by linking the echolink node on my holiday location to an echolink node at home.
Echolink with SVXlink
The idea of running a dedicated PC for this matter I didn’t like. After some searching around on the internet, I found it is possible to run a echolink node on an RaspberryPi with a program called SVXlink. That’s exactly what I was looking for! SVXlink is even that efficient, it can run on one of the first RaspberryPi’s. I had a model B (first gen) laying around so I digged it up and installed SVXlink on it. Building an echolink node with a Kenwood TM-D710 as RF-bridge is really really simple. Just get an real cheap USB-audio dongle, connect the echolink cable from the TM-D710 to it and attach the cat-cable from the TM-D710 to a USB-serial adapter to the RaspberryPi. I found some good howto’s to install and config SVXlink on a RaspberryPi so I walked true those. Actually it was quite simple when it’s runs.
The Echolink network
All I needed now was another echolink node – RF-bridge in my hometown that was linked to our local frequency. My buddies Rob, PA3X and Gerald, PA9G where following my echolink activities with the RaspberryPi and where immediately enthusiastic to step in and setup their own node. They also had unused RaspberryPi’s laying around so we copied my SD-card and did some minor changes to the setup for them. Back at home the attached their nodes to the internet and to their VHF/UHF-radio’s. Rob started with attaching his Yaesu FT-817 and we adjust his config for VOX-usage. After some tweaking it worked quite nice. But Rob wasn’t totally happy with the VOX-setup. He had a Kenwood TK-880 laying around and wanted to use this for his setup. Now we needed to convert his setup to use SQL-carrier signal which he pulled out of the TK-880. Attached to one of the GPIO-ports on the RaspberryPi we struggled somewhat with the setup. But after a while we’ve got it up and running. Connecting my node to his resulted in a nice bridge. I was able to talk into my HT and copy activity on our local frequency.
Limitations
The initially idea was to bring the node with me on holiday. But after extensively testing I found out that you need port forwards to be able to link two nodes. I already found out there was no internet in our holiday accommodation. It would be virtually impossible to create port forwards if I even had internet at all. So I left the node at home. Not all effort was wasted because it’s quite fun to connect all our nodes together, use all local frequencies and dummy loads to restrict usage to home. This way we can create sort of a private network with connections to all kind of echolink nodes.