In the early days of Amateur Packet Radio, it was necessary to use a “Terminal Node Controller” (TNC)
with specialized hardware. Those days are gone. You can now get better results at lower cost by
connecting your radio to the “soundcard” interface of a computer and running free software.
The Raspberry Pi (RPi) is a good platform for running a software TNC, APRS digipeater, and IGate. Why
use a larger computer and waste hundreds of watts of power? All you need to add is a USB Audio
Adapter ($8 or less) and a simple PTT circuit to activate the transmitter.

Dated August 2017