MCAS Beaufort and MCRD Parris Island Monitoring Trip

Having read Larry Van Horn's request in Monitoring Times for information on a 380-400 MHz trunking system that could be in the area of MCAS Beaufort and MCRD Parris Island, I traveled to Beaufort, SC this morning to search for evidence of one. I heard no indication of such a system in Beaufort at the present time; there wasn't even a control channel active in that frequency range.

The trip wasn't a total waste, though. I found that some of the 400 MHz frequencies I have heard in use at MCRD Parris Island are not in fact conventional repeaters but actually an LTR trunking system. For quite awhile I have noticed that there were multiple conversations going on these frequencies but I haven't been able to find the transmissions using CTCSS or DCS. During today's trip, it finally struck me to try setting up the frequencies in the BC 396 as an LTR system. Sure enough, the 396 began tracking talkgroups and conversations started making sense. Most of the traffic was related to coordinating recruit training with a few talkgroups that seem to be used by civilian support personnel. By no means do I profess to be an LTR system expert, but here are the frequencies, settings, and talkgroups that I found to work:

MCRD Parris Island LTR System
406.3625 LCN 1
408.5625 LCN 2
410.3625 LCN 3
410.7625 LCN 4

0-01-006 Training Coordination
0-01-010 Training Coordination
0-01-011 Training Coordination
0-01-012 Training Coordination
0-01-014 Training Coordination
0-01-016 Training Coordination
0-01-017 Training Coordination
0-01-032 Motor Pool (civilian)
0-01-038 Civilian Support Personnel
0-01-041 Civilian Support Personnel
0-01-057 Training Coordination


Besides the LTR system, I also heard some VHF conventional activity at both bases:

MCAS Beaufort
138.425 - Security Forces
138.650 - Units wkg Tower for movement on airfield
139.975 - Telemetry

MCRD Parris Island
140.950
141.950 - Range Ops
142.500 - Range Ops
143.650 - Range Ops


I also came across what I can only call a curiosity while searching VHF. On 143.025 I heard Close Air Support traffic from SCOTT 21/22 flight in FM mode. At times, this traffic sounded like it was coming from AM transmission being picked up the input of a repeater then being transmitted over the repeater in FM mode. I never heard anything on any other frequency that could have been what was being rebroadcast.


Mac McCormick, KF4LMT
kf4lmt@comcast.net