Well, I’ve provisioned a couple of D-STAR gateways, and have helped with some Icom repeater work, but I have never built a repeater from the ground up. I have hit a milestone in that area.
I have been following, with interest the work of G4ULF and his Linux based G2 compatible D-STAR repeater project. It uses the GMSK boards originally created by 7M3TJZ and the new design by PA4YBR. I have the loan of such a GMSK board, but recently G4KLX made major strides with his sound card based controller program and so I thought I would give it a try.
This design requires a cheap, unfiltered sound card like those USB fob type for around $8. A pair of radios that can handle the GMSK modulation (I am working with a Yaesu 817, maybe my 847, and a couple of Friendcom FC-301/D UHF radios, for experimenting – a true repeater needs some solid radios, but these are great for learning the system), a circuit to handle the PTT/COS signalling for the program, currently the Vellman 8055 board (< $50 on the Internet in Kit Form, look for V110 if you want a preassembled unit) is supported. Then the usual duplexer, antenna, power supply, and a PC (Windows or Linux) to drive it.
Tonight, I worked through an issue in getting my transmitter working (pin 8 of a Friendcom must be pulled high to work), and using the 817 as a receiver, I was repeating D-STAR, and the ole’ club callsign was there for a legal ID. I still need to tweak audio levels a bit, as it is heavy R2D2 at the moment — but what a blast. BTW, this code will also talk to a gateway. I don’t have a gateway installed, but on one of my Linux boxes I set up a UDP listener and saw the data coming over for a gateway.
I’m not going to have a lot of chance to work on this again until after Thanksgiving (maybe some time tomorrow, to tweak) — but this is going to be a fun adventure that will hopefully lead to some new applications for D-STAR from yours truly.
73 for tonight