Extend a POTS to HX5000 with HT503

[phoneman429]

We have done this with Audiocodes and KB articles with no problem, used the HT502 to HT503 to extend a fax in outbuilding with no wired infrastructure, was a piece of cake with HT documentation, with HT503 being third the cost, it seemed like an even better solution for the 5000 needing 1 C.O. extended to it, I've been beating my head against the wall for 3 days, cannot use combination of docs to get something so simple going. Has anybody done this? Any suggestions would be greatly appreciated, thanks, Mike.