Seven digital stations handled eight digital messages during the November 8 Communications Exercise (COMEX). All traffic reached the appropriate Military Auxiliary Radio System (MARS) stations. The messages provided status of the following for the station's county:
MEDICAL FACILITY STATUS
All messages were exchanged using the RMS Express software package. The majority of messages originated on VHF packet (145.01 Mhz). Those messages in the Tulsa area were digipeated on the KT5DIG-7 digipeater, located in Mounds, OK. The digipeater operates on a 75 AH deep cycle battery for operation "off the grid". During normal commercial power operation, the battery is charged by a Battery Tender charger that is capable of providing up to 1.5 Amps continuous charging capability.
The central mail hub for the exercise was the AE5ME-12 system, which is located on VHF packet (145.01 Mhz) and HF Winmor (7036 kHz) in Broken Arrow, OK. The system runs as an RMS Relay station using the BPQ32 software, which allows messages that enter the system to be retrieved by the recipient at a later time using the RMS Express software. The computer system consists of an HP Stream 7 tablet in a docking station. The use of a tablet minimizes the amount of power required to run the computer. The computer is connected to two Tigertronics SIgnalink USB soundcard interfaces. One interface goes to a Kenwood TS-2000 HF/VHF/UHF radio, the other to a Kenwood TS-570D HF radio. Along with a backup Kenwood TM-241A VHF radio, the combination of radios provides full redundancy on HF or VHF in the event of any individual radio failure. One soundcard interface operates on AFSK 1200 bps packet, the other operates on HF Winmor.
The complete system was disconnected from power mains and antennas from 3 AM to 6 AM local time to protect against damage during the simulated CME event. At 6 AM all antennas were reconnected and the system was restarted on deep-cycle battery power. The entire system was functional in two minutes after restoration of power.
Once the message was received from WY7RM that MARS was requesting county reports, a message was sent to KF5RCI, AD5JL, WB5ANX, WA5VXI, KD5NJR, KC5SHE, KF5RHH, KF5TVG, AE5ME and KC5RBH requesting reports. AE5ME, KF5RCI, KF5TVG, WA5VXI, and KD5NJR responded before 12 noon local time. AD5JL, AE5ME (second report for Rogers county), and KC5RBH responded before 3 PM local time. WB5ANX had technical issues connecting on packet. KC5SHE was ill and KF5RHH had to go to work before receipt of the request.
Two sets of messages were sent to WY7RM and KC5WMZ, both of which retrieved the sets of messages during the afternoon on 40m Winmor. WD9GET operated directly with KC5MWZ on 40m Winmor.
An actual solar event prior to the simulated CME caused 40m band conditions to have a large amount of fading. There was also a CW contest with many operating stations in the 3000 Hz bandwidth of the HF station. HF Winmor was still successful in operating in the challenging conditions while avoiding interference with the existing CW traffic.
With appropriate digipeaters placed between Tulsa and OKC, VHF would have been an acceptable alternative if the 40m band completely failed.
LESSONS LEARNED/ACTION ITEMS
1) 40m Winmor was found to be a very robust method, even with less than ideal 40m band conditions.
2) Baofeng UV-5r HTs were issued to stations for the exercise. It was found that connecting them to external antennas would desense the receive portion of the radio. We are currently testing an HT alternative from TYT that seems to be much more resistant to front-end overload.
3) All county EOCs should have an RMS Express station capable of connecting to their local VHF digipeater or using HF Winmor.
4) There will be a debrief session on Saturday, November 21st at 2:30 PM at the Broken Arrow Central Library (300 W. Broadway). All participants are encouraged to attend to share in individual "lessons learned".
Many thanks to Gerald KC5MWZ and Roland WY7RM for their work on the MARS side of the exercise. Also thanks go to the crew that sent RMS messages via VHF packet to the AE5ME-12 system.
Thanks to Jeff, AE5ME for this information