These days we use a WSPR tracker which you can see details of (here).
Two revisions of this board have been made.
Carries 3 major components:
ATmega328P mcu
Ublox NEO 6M GPS module
RF4463PRO RF module
APRS transmitter, geofenced to know regional frequencies.
Custom firmware and PCB layout.
~150 mile max range.
11 grams.