turns out the new base station (and closest to us since it is by our shop) is the only one in the network that uses glonass (sp?) satellites.  It was trying to get the 500 to use one or more of them which it can't.  Once that was taken out of the mix, we have been up and running.

Question:  On the 500 with network vrs-rtk, we lose signal sometimes.  Like yesterday for 30 min.+ in the late morning and again about 3:00.  Evidently due to satellite problems.   Yet we run a 250 on a sprayer and NEVER lost signal.  Why?