Here is the Troy Amateur Radio Association's new Echolink node; a Raspberry Pi Model B+ running thelinkbox. Full disclaimer: I am not an 'Echolink guy', and I empathize with those that do not consider Echolink to be 'real radio'. However, I also appreciate those whose situations preclude them from getting on the air via RF, and think Echolink and its ilk are a perfectly reasonable solution. I also like to help out our club when I can, and in this case it was a perfect marriage of INTERNETS and radio, and who can argue with that?
Since the Raspberry Pi has no built-in capacity for audio input, an external sound card is used. This one costs about $6 and can be had on Amazon. The USB to serial adapter (~$9) connects to an AMI-2 board that had been purchased for the club. It's not strictly necessary, as a circuit to talk to the link radio can be built fairly easily. But since the club had the AMI-2 already, I decided to not make my life any more difficult than necessary.
The radio inherited for the project is an Alinco DR-605, which is total overkill. That said, until the club finds another need for such a radio, there's no reason to replace it with something a little less hefty.
Unfortunately, the node cannot be colocated with the repeater, given access issues and a lack of Internet at the site. Further to this, VOX is our current method of carrier detection, which is less than desirable. I do notice some audio dropouts when listening to the audio from the node; I'm not sure if this is an issue with the sound card (hey, what do you want for $6),
thelinkbox, or Internet connectivity at the site.
I'm currently putting together a personal link setup (i.e. K2MTS-L) based on OM KP4TR's excellent Naked Node design. I may swap this out for the N2TY-R node should it prove to work well.