Q: If you buy the infra ready set and down the road want to upgrade to the radio is it necessary to buy a whole new set? If not what is required to upgrade the existing set?
A: The DT400 or DT402 can be converted to DT402D duplex radio or DT402R simplex radio. The conversion must be done by Digitrax.
If you plan on using the IR features of the DT400 or DT402 , you will need one or more UR90 infrared receivers.
If you convert the DT400 or DT402 to duplex radio, you will need a UR92 duplex transceiver which handles both infrared and duplex radio signals.
If you convert the DT400 or DT402 to simplex radio, you will need a UR91 simplex receiver which handles both infrared and simplex radio signals.