16 December 2009

USCG Helicopters using Digital Voice and USCG UHF NET Frequencies?

Back in August, I posted an article about the USCG in the Savannah area using CG 113 (163.1375) in P25 digital voice mode for communications as part of the new RESCUE 21 communications system. The last week or so has provided some updates on how the Coast Guard in the Savannah area is using the new frequencies.

Last week, I began hearing MH-65Cs from CGAS Savannah using CG 113 with Sector Charleston and with some of the area USCG boats. I've also heard them request to use CG 111 and CG 112 with Sector Jacksonville. The three digit identifier indicates the use of P25 digital voice and I have heard them use P25 digital voice so this confirms that the helicopters now have radios capable of utilizing P25.

Today, when 6565 departed CGAS Savannah for AirFac Charleston, Sector Charleston asked them to switch to "UHF Channel 410" for guard. I'd never heard reference to that channel so I immediately threw a couple of radios into search mode. In short time, I found Sector Charleston on 413.000 working 6510 in P25 digital voice. 6510 continued to use this frequency for guard radio traffic with Sector Charleston until they landed later at CGAS Savannah. 6565, after initally having no joy on the frequency, began keeping their guard on "CG 410" as well. It seems that in addition to a set of VHF NET (or what the USCG units seem to refer to as "CG") channels, there is also a set of UHF NET (or "CG") channels.

For those that enjoy listening to the Coast Guard, it is definitely a time to begin looking for a digital capable scanner if you don't have one now. It is also time to begin looking beyond the Marine VHF and HF frequencies for both Coast Guard surface and air communications. Just as USCG assets have begun moving away from such old favorites such as 5.696 USB to the COTHEN HF system they are beginning to move away from Marine VHF to the RESCUE 21 system.

Mac McCormick III, KF4LMT