The KF161-Tracker is a PIC16F628A or PIC16F648A based tracker module similar to TinyTrak, but designed to fit inside a Bosch KF161 transceiver. It is available as a kit from Museum "Jan Corver".
KF161-Tracker uses AprsTracker open source firmware.
English documentation is available at http://www.jancorver.org/en/bouw/track/files/man130.pdf
Information in Dutch is available at http://sharon.esrac.ele.tue.nl/~pe1icq/projects/kf161-tracker.html