Originally Posted by Dave H

Don't believe the Dirt Champ and Robitronic transponders will work with the MyLaps-AMB timing systems most tracks use. They are based on a different technology.

The only practical alternative for most racers that I am aware of is the newly updated MRT deal, but I don't know if that is available yet. And it might leave you at risk of not working with future MyLaps-AMB track updates like recently happened.