Frequently Asked Questions

Military Auxiliary Radio System Frequently Asked Questions

What is MARS?  MARS stands for Military Auxiliary Radio System.  MARS is a Department of Defense sponsored capability authorized under DOD Instruction 4650.02 and implemented in Army Regulation 25-6 that organizes and trains the best, licensed amateur radio volunteers to operate in military radio networks to support tasked requirements establishing high frequency radio contingency communications.  

MARS membership is limited to Amateur Radio operators, who operate their Amateur Radio stations as military Auxiliarists, usually from their homes.  There are no government agency or military unit MARS stations.

The Army MARS mission is to—

What are the requirements to volunteer for MARS?  In order to apply for MARS membership, the applicant must:

Once you are a MARS Auxiliarist, there are ongoing requirements. You must:

And you will be expected to perform basic radio network task such as:

What training do MARS Auxiliarists receive?  MARS members are trained and proficient in formatted text messages and voice radio procedures.  Members are also proficient in sending and receiving both plaindress and codress (encoded) messages.  Members receive training using military standard communication protocols such as MilStd 188-110A. 

What is an Auxiliarist?  Auxiliarist is a term used to describe a member of a military auxiliary, such as MARS. In Army MARS specifically, the term is used to describe a MARS member that has successfully completed their Level 1 Basic Training.

Do I have to get my radio modifiedProbably.  According to the NTIA manual of regulations, MARS Auxiliarists may modify their personal Amateur Radio equipment to operate on government frequencies when in MARS service, provided the unwanted emissions when operating outside the amateur radio band meets the technical standard of FCC Part 97 (Note: this permission does not extend to government or military entities).  Most amateur radios can be modified to operate outside the amateur radio bands, and the manufactures of these radios usually have an instruction sheet to modify the radio.  These instruction sheets are also available publicly from various sources on the internet.  HQ Army MARS does not retain a library of these sheets, nor do we modify radios.; however other MARS members in your area probably have the information  you need.

What kind of antenna do I needMARS Auxiliarists use all kinds of antennas in MARS service, but there are some differences from antennas utilized in Amateur service.  Frequency assignments are throughout the entire HF radio spectrum, are not selected for proximity to Amateur radio bands, and Auxiliarists are expected to operate on any of them from 2 to 30 MHz.  This requirement poses a different technical problem than operating on harmonically related bands.  Effective MARS stations utilize antennas that are optimized for a low take off angle, for instance a dipole at least 1/2 wavelength above ground on frequencies likely to propagate 1000 km or more (for instance a dipole at least 40 feet high for daytime operation).   Terminated Folded Dipole at least 90 feet long, dipole antennas with open wire feed and remote, automatic antenna tuners directly under the antenna are effective, as are verticals with symmetrical elevated ground radials, or more than 30 buried ground rails, and fed with a remote, automatic antenna tuners directly at the base.   NVIS operation is not a priority.

My unit is seeking MARS membership.  What do we need to do?   MARS membership is open to individual persons, who are citizen volunteer amateur radio operators, who support US military activities.  These individuals, referred to as Auxiliarists, typically operate from their home using their personally owned Amateur Radio station and are not affiliated with a military unit.    Auxiliarists are guests on the US military radio network.

Army Regulation 25-6 establishes the US military HF radio network for the purpose of unit mission training, individual soldier training, and DoD tasked missions.  AR 25-6 authorizes US military units to operate on this network as they are, without MARS membership or registration.  There are no government owned MARS stations as these are now simply organic capabilities of the respective unit.  Military units are not eligible for MARS membership, rather they are supported by MARS.  

My unit is interested in conducting on-air HF training, how do I request support?  For units interested in doing on-air training and testing, please contact the Fort Huachuca Gateway station at:  520-533-7072 and DSN 821-7072.  Via email, contact: 

Given your proposed training dates and times, we will coordinate with you as to which MARS HF frequencies will be most suitable for the test and we will also coordinate to have a variety of MARS stations on the air to support your training.  We will also coordinate what call signs will be used for the training.


If my unit wants to train with MARS do we have to request HF frequencies for the training?  No.  MARS HF frequencies are issued to the U.S. Army Network Enterprise Technology Command from the Department of Army Spectrum Management Office and are authorized for use by Army units in the United States to conduct this type of training.   The Ft Huachuca HF Gateway can supply your unit with a CPA plan.

When are HF Gateway personnel available to discuss training requirements and for conducting on-air training?  The Fort Huachuca Gateway is manned 5 days a week (M-F) from 1500-2359Z Hours.  Our operators monitor multiple national frequencies and the 3G network.