Recently, there has been an increase in activity on the JNCR Dahlgren trunked system. Most of the traffic has been on talkgroup 22311. The system is obviously still in the testing stages--the primary base radio traffic remains on the LTR system. The switch to the new system may occur when public safety agencies on the base move into a new communications center.
While at Great Falls Park on Sunday, I picked up a few frequency confirmations:
170.0500 [NAC 4C5] Great Falls Park
169.6875 [NAC 4C5] C&O Canal National Historical Park (This frequency was strong at Great Falls. A reference to the "Monocacy Aqueduct" was monitored. 170.3625 [NAC 4C5] was active at same time, but much weaker.)
The family and I took a trip up to the Manassas Battlefield Sunday afternoon before the Super Bowl. Here are some updates to National Park Service frequencies:
172.7250 [NAC 47C] Manassas NBP
170.0500 [NAC 5C2] Monocacy NB (this frequency may be shared with Antietam NB)
170.3625 [NAC 4C5] this frequency was weak from Manassas, but has the characteristic Park Service NAC. I couldn't make out who it was, but suspect it may be C&O Canal NHP. A user on RadioReference has also reported hearing 169.6875 [NAC 4C5]; this may be another C&O repeater.