Amateur Radio Community Invited to Take Part in MARS Exercises on 60 Meters (April 30 – May 6)

Radio amateurs are invited to take part in a series of monthly MARS exercises in support of the US Department of Defense. During these exercises, MARS members will exchange messages with participating Amateur Radio operators using voice and digital modes on the 60m band. A list of dates for these exercises has been published on the ARRL website. The next MARS-Amateur Radio Interoperability Exercise is scheduled for April 30 – May 6. This exercise will be immediately followed by the Annual Armed Forces Day Cross-Band Test on May 7-8 (see following announcement).

MCACS members who are skilled HF operators might wish to participate in these exercises. Others might find it instructive to listen in to become familiar with the protocols used by experienced operators to pass ICS messages in the HF radio environment.

From the ARRL webpage cited above: “ ‘In addition to voice calls, I want to introduce passing ICS 213 messages in both voice and digital modes to enhance the overall interop experience,’ said US Army MARS Chief Paul English, WD8DBY. ‘Our exercises will yield the frequencies to other scheduled exercises or mission activations, which may be called by other agencies for interop support (e.g., hurricane, wildfire, etc). We regularly instruct MARS members to work cooperatively with the amateur radio community during the use of the 60-meter interop channels. We will continue to track our 60-meter usage and activities.’ “

MARS operations are usually conducted on government frequencies outside the Amateur Radio bands. The 60m band is unique among the HF bands allocated for Amateur Radio use in that this band was established primarily to promote interoperability between government and Amateur Radio stations during drills and emergencies. Amateur operations on 60m are limited to five designated channels, each 3 kHz wide, and are secondary to government users on those channels. (In other words, we must yield the frequency when a government user requests to use it.) When using voice or digital modes, emissions must be constrained to the bandwidth of a typical 2.8 kHz upper-sideband (USB) voice channel, in contrast to the 75 and 40m bands, where LSB is normally used. In addition, we are limited to an effective radiated power equivalent to delivering 100 W into a half-wave dipole. A General or higher class license is required to transmit on 60m.

Normally, during these exercises, Channel 1 will be used as a calling frequency, with messages being passed on the other four 60m channels. So you will need a list of all five 60m channel dial frequencies and the corresponding center frequencies.

Channel  Dial Freq   Center Freq
  1      5330.5      5332
  2      5346.5      5348
  3      5357.0      5358.5
  4      5371.5      5373
  5      5403.5      5405

For example, Channel 3 has a dial frequency of 5357 kHz. Since the channel is nominally 3 kHz wide, the center of the channel (for digital mode communications) is 1.5 kHz above the dial frequency, or 5358.5 kHz. For example, if you were running Winlink using the Ardop or VARA HF protocol, you would set your radio to the USB mode. In the Winlink session window, you would enter 5358.5 as the center frequency, and the Winlink software displays the corresponding dial frequency of 5357. If the Winlink software is directly controlling your radio, it will be tuned to 5357 kHz.

When operating CW on 60m, the rules are a little different. CW operation must take place at the center of your chosen channel. Thus, for example, to operate CW on Channel 2, you must set your operating frequency (dial frequency) to 5348 kHz. CW transmissions generate sidebands for several hundred hertz on both sides of the operating frequency. The reason that the FCC wants you to transmit in the center of the band is to ensure that your sidebands remain within the allotted channel bandwidth.

Did you know that WWV and WWVH announce upcoming and current Military Auxiliary Radio System (MARS) and U.S. Department of Defense (DoD) exercises? These announcements provide information to Amateur Radio participants regarding the purpose, dates, times and locations of the exercises and other information. WWV airs MARS announcements on the 10th minute of each hour, and WWVH uses the 50th minute. Each announcement will air for about two weeks, prior to and during each exercise.

Annual Armed Forces Day Cross-Band Test (May 7-8)

For a different aspect of interoperability with other services, consider participating in the Annual Armed Forces Day Cross-Band Test on May 7-8. For this event, several military radios stations across the US — including stations at the Pentagon, Andrews AFB, and Fort Meade locally — will be making contacts with Amateur Radio stations. The military stations will initiate these contacts by making calls on designated government frequencies according to a published schedule and listening for responses in various Amateur Radio bands.

Upcoming Red Cross Comm Exercise

The next national Red Cross emcomm exercise is scheduled for Saturday, May 8. These exercises are held twice a year to familiarize Amateur Radio operators with American Red Cross message protocols, primarily using Winlink. Since we train to use Winlink within Montgomery County and throughout the Maryland-DC section, these exercises are a great opportunity to practice our skills and see how ARC uses digital communications for their shelter operations. MCACS members will be hearing more about this exercise in the next couple of weeks, but you can subscribe directly to the ARC EmComm Message Board on

If you are not familiar with, it is the successor to Yahoo Groups, and an internet site that hosts many affinity groups covering a wide range of topics. A great many Amateur Radio groups have moved their operations to, including interest groups for NVIS antennas, nanoVNA owners, Skywarn, fox hunting, and practically every brand of Amateur Radio gear, just to name a few. First, you’ll have to get a free account; then you can subscribe to the ARC EmComm message board.

On-Air ICS Training

As mentioned in a recent email to the members, we have embarked on a campaign to get more of our members to complete the four FEMA courses required for full membership in MCACS. For the next several weeks, on each of our weekly nets, we will be going sequentially through each of the online courses together as a group, which each participant clicking through the slides on their own computer while we discuss the material on the net. We started with The IS-100.c course on January 26, completing Lesson 1. On February 2, KC3MIX presented Lesson 2. We’ll report our progress each week on the Calendar page, so if you miss a net for some reason, you can go through the material on your own.

If you missed either of these nets, you can easily catch up. Just click on the course link and read through the first 41 slides. It will probably take you less than a minute per slide.

Eventually, when it is time to take the exam, you will need a FEMA Student ID. It is exceptionally easy to obtain your Student ID. Just click here and fill in the online registration form — which only asks for basic information. Registration is not required to access the course — only the exam.