Originally Posted by
Bob Malphurs
RC4 Hybrid and all earlier AMB/MyLaps PT's are forward and backward compatible (RC2, RC3 and RC4 decoders).
....Rc4 forward compatible only (RC4 decoder). Unless you need a new transponder keep what ya got! Only thing you will get with the RC4 PT is telemetry and only if the tracks software will support that feature.
If you need a PT or just want to upgrade order the RC4 Hybrid at this point! Will work at all tracks!

NO - the new rc4 transponders are not compatible with rc3 and earlier decoders.
So rc4 transponders will not work at all tracks, only those with the new rc4 decoders (which most tracks do not have).