can I use a TCS DP5 mobile decoder with a Digitrax Zephyr Xtra
yes you can.
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
That's the advantage of the NMRA DCC Standards and Recommended Practices -- practically every brand of decoder is compatible with every brand of DCC system as far as the basic functions are concerned.
This should help you if they are HO scale. http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/Life_Like/Proto_2000_E7/Proto_2000_E7.html
Pete