The Motorola RDV2020, RDV2080d, and RDV5100  have some compatibility issues with Motorola XV1100, XV2100, and XV2600 two way radios due to Frequency Changes mandated by the Federal Communications Commission.  In everyday terms, this means your new Motorola RDX product might not work with your Motorola XTN even though you have them programmed to the same channel and code.  This does not mean your RDX and XTN products aren’t compatible, they just need to be reprogrammed.  The Factory Default on the RDV2020, RDV2080d, and the RDV5100 is the same frequency combination as that of frequency 20 code 1 on the XV1100, XV2100, and XV2600.  www.2wayradiodirect.com will gladly walk you through reprogramming your XTN Series two way radios to work with your new RDX VHF two way radios.