Lots of info
USBlink http://www.g4ilo.com/usblink.html USB sound card + VOX interface to PTT switch + HT
Some notes on available hardware
- Kenwood TH-D74A handheld with built in GPS and APRS
- Kenwood TM-D710A mobile with a UBlox GPS, installed in the Yaris.
- Kenwood TM-271A mobile which has a data interface buried inside.
- Byonics Tinytrak 4
- Byonics MT8000
- Several abandoned Android phones
Other 2M HTs including two ICOM F11s which have no external power connectors (battery only) and a Kenwood TH-F6A
Breaking this all down I need a receiver to work as an iGate with a Pi 3, and a transmitter to implement a Digipeater.
The cellphone APRSDroid solution appeals to me too, later maybe. https://wcares.org/special-interests-3/aprs/aprs-hardwired-cell/
Step one is the iGate as a data sink since I can already use the Kenwoods as sources. There is no iGate close to my house. So that is my first need.
iGate on a Pi
Two common approaches (1) SDR (2) sound card + HT. I have a cheap USB sound card and a RTL-SDR on order now. The RTL-SDR appeals to me the most but it's receive only, so it can't function as a digipeater.
A good article on the sound card approach is here https://wcares.org/special-interests-3/aprs/aprs-raspberry-pi-virtual-tnc/ It's out of date but still good.
Sam Buchanan's notes: http://www.vansairforce.com/community/showthread.php?t=30180
Eventually, if I end up using one radio for receive and one for transmit, how do I isolate them? This is what duplexers are for, but not when you have two radios operating on the exact same frequency. Why would I do that anyway? Just use one radio. One way is two antennas, and pull the receiver input to ground when transmitting. http://www.ok1rr.com/index.php/technical-topics/39-yet-another-front-end-saver
sudo apt install git-all libasound2-dev cmake -y git clone https://www.github.com/wb2osz/direwolf cd direwolf
Then read and follow instructions in README.md, basically
git checkout dev mkdir build && cd build cmake .. make -j4 sudo make install make install-conf
Xastir - this is a desktop app so I am not looking at it.
Argent Data Systems
Products for amateur radio including APRS applications
2m Transmitter MX146 from SRB -- This is a 500 mW transmitter, $70
OpenTracker+ is open source / open hardware and uses a Motorola MCU.
These are controllers, connects a data stream (eg weather or gps) to a Kantronics TNC.
They now have a Tracker2 with a 5 watt 2m radio now. T2-301 $229
Maker of TinyTrak controllers and MicroTrak transmitters
Purchased way back in 20 Aug 2010 and tossed into a "future projects" box. I got a TinyTrak4 controller kit and a MicroTrak MT8000 which is like a TinyTrak3 with a built in 8 watt transmitter.
Information from the source: http://www.byonics.com/tinytrak4/
Links from Andy Volokitin
First off I am looking at Xastir.
Xastir on my Mac Book Pro
I moved everything to this page... Xastir