Just had a chance to monitor some changes at Davis Monthan Air Force Base in Tucson, Arizona. They have had a UHF Motorola trunked system there for a number of years, but now have started a separate P-25 UHF system as well.
The new system is using a System ID of 3F6 and the site at the base shows as Site 102. It is not showing as being networked with any other sites yet.
The frequencies are as follows:
409.2750
409.4500
409.5625
410.5625
All frequencies associated with this system were displaying a NAC of 3F0. These 4 frequencies were taken from the original DMAFB UHF system channels. It's unconfirmed, but this may be the start of converting the entire base to a single P-25 trunked system.
The system now has some limited users, and at least one talk group was being heard over both systems. But most of the activity is still on the original base trunked system:
http://www.radioreference.com/apps/db/?sid=3711