The Tracker2 series has been discontinued.
Fleet Management Interface
The Tracker2 has been produced in a number of variations.
OT2m Stand-alone unit in a metal enclosure
T2-135 Plug-in board for the Alinco DR-135
T2-301 Plug-in board integrated with the FC-301/D transceiver
Proto E - Identical to OT2m v1.0 with the exception of some PCB markings, thermal vias, and C2 being replaced by 0.001uF cap.
Proto D - Flawed prototype, never released
Proto C - The most widely distributed version during beta testing. Proto C and earlier used all through-hole parts and had a passive input filter.
Proto B - Early prototype with limited production
Proto A - Early prototype with limited production