MARS (Military Auxiliary Radio System) is a U.S. Department of Defense-sponsored program that uses licensed civilian amateur ("ham") radio operators as volunteer auxiliaries to provide emergency and contingency high-frequency (HF) radio communications. 

Key Aspects of MARS

• Purpose: It serves as a vital backup communication network for the U.S. military, federal agencies, and disaster response teams when regular or commercial infrastructure (such as cell towers and internet) fails. 

• MARS RADIO Network: The Air Force and Army operate programs like MARSRADIO, which provides 24/7/365 HF radio and telephone patch support for U.S. military aircraft, allied units, and agencies like the Civil Air Patrol. 

• Membership: Volunteers must hold a valid FCC amateur radio license, undergo security vetting, and complete specialized training in military communication protocols and assigned non-amateur frequencies. 

• History: The program originated in 1925 as the Army Amateur Radio System before evolving into its current structure managed by the U.S. Army and U.S. Air Force. 

To join the Military Auxiliary Radio System (MARS), applicants must be at least 18 years old (17 for Air Force MARS), hold a valid FCC amateur radio license, and possess a High Frequency (HF) radio station capable of running at least 100 watts on frequencies outside standard ham bands. 

Core Eligibility Requirements

• Age & Citizenship: You must be at least 18 years old (or 17 depending on the service branch) and a U.S. citizen or a lawfully admitted permanent resident alien. 

• Amateur Radio License: You must hold a valid FCC amateur radio license (any class for Army MARS, though General class or higher is strongly preferred and required by some regional or Air Force guidelines). 

• Background Check & Vetting: Applicants must sign a non-disclosure agreement (NDA), undergo a background check, have no felony convictions or pending indictments, and maintain good moral character with no drug or terrorist associations.

Station & Technical Requirements

• HF Radio Equipment: You need unrestricted access to a transceiver, antenna, and computer system capable of operating across 2 to 30 MHz with an output power of at least 100 watts.

• Out-of-Band Capability: Your radio must be capable of or modified for out-of-band/MARS frequency operation, as MARS networks run on assigned military-allocated spectrum just outside traditional amateur radio bands.

• Digital & IT Proficiency: You must have a computer running Windows 10/11 with a sound card, internet access, and the ability to independently configure networking, specialized digital modes (such as MIL-STD-188-110A serial tone modems), and military messaging software (such as ACP 127).

• FEMA Courses: Completion of free online emergency management courses (such as FEMA IS-100 and IS-200) is typically required within your first year. 

Ongoing Participation Commitments

• Activity Hours: Members must log a minimum participation requirement—typically 12 to 18 hours on HF radio nets per calendar quarter—along with regular net control duties and monthly reporting. 

• Exercises: Participation in periodic readiness drills, annual emergency exercises, and specialized military communication tasks is mandatory. 

• Volunteer Status: MARS service is strictly unpaid, and members receive no government-issued equipment or stipends; you contribute your own time, power, and gear.

Official application forms for both the Army and Air Force MARS programs are available directly online through their respective official military repositories. You must fill these out digitally on a computer, as handwritten or mailed submissions are not accepted.

1. Army MARS (Form AM-1)

The Application to Operate a MARS Station (Form AM-1) is processed by the U.S. Army Network Enterprise Technology Command (NETCOM). 

• Where to Download: You can download the latest official fillable PDF variant directly from the Army NETCOM MARS Portal or open the Form AM-1 Document directly. 

• Submission Instructions: Once completed on your computer, follow the direct filing steps detailed on the US Army MARS Registration Hub to email your electronic application file to the specified military processing office at Fort Huachuca. 

2. Air Force MARS (Form 3660)

The USAF Military Auxiliary Radio System Form 3660 is the standard onboarding application used by the Air Force auxiliary branch. 

• Where to Download: You can fetch the official interactive digital layout on the Air Force MARS Platform.

• Submission Instructions: Fill out your station capabilities, technical gear, and contact details. Ensure you attach a clear copy of your valid FCC amateur radio license and email the file directly to afnic.mars@us.af.mil alongside your local State MARS Director. 

MARS requires a minimum of 12 to 18 hours of on-air participation per calendar quarter (72 hours total per year), plus roughly 4 to 5 hours per week during your initial onboarding training. 

Quarterly & Annual Participation Minimums

• • On-Air Net Time: You must log at least 12 to 18 hours per calendar quarter (depending on whether you join Army MARS or Air Force MARS). This typically breaks down to checking into scheduled high-frequency (HF) nets that run daily or weekly. 

  • Annual Total: Expect a baseline of 72 hours per year of active net operation and task participation. 

  • Periodic Exercises: Members must participate in at least one to two major national or regional communications exercises per year, which often span several hours each (e.g., 3+ hours per drill). 

  • Administrative Reporting: You are required to submit a monthly activity and station status report to your local or regional coordinator, even if you had zero operating hours in a slow month.

Initial Training & Onboarding Phase

• 1. Timeframe: New members enter a probationary period and have up to 270 days (roughly 9 months) to complete the official Basic Training Course and required FEMA certifications (IS-100 and IS-200). 

  2. Weekly Investment: Completing the training course load and practical on-air tasks typically requires 4 to 5 hours per week of focused study and practical net practice.
     
     

Real-World Time Investment (Active Operators)

While the official rule is 12–18 hours per quarter, many dedicated members and net control operators spend 15 to 30 hours per month handling digital traffic modes (like M110A), mentoring new trainees, or running local and regional nets. 

MARS requires an High Frequency (HF) transceiver system capable of operating across all frequencies from 2 to 30 MHz with at least 100 watts of output power, along with a computer interface, specialized digital modems, and a tunable antenna. 

Core Station Equipment Requirements

• HF Transceiver: A transmitter and receiver (or combined transceiver) that covers 2 to 30 MHz and delivers a minimum of 100 watts of output power to ensure reliable long-distance communication. 

• "MARS-Modded" Radio: The transceiver must be capable of transmitting on military-allocated frequencies outside standard amateur (ham) bands, which typically requires a hardware or software expansion (known as a MARS/CAP modification). 

• Antenna System: An antenna (and external tuner if needed) capable of efficiently transmitting and receiving across the 2–30 MHz spectrum. 

• Computer & Operating System: A reliable computer (typically running Windows 10/11) capable of managing local area networks, running specialized software, and handling system recovery without external technical assistance.

• Sound Card & Data Interface: An audio or digital interface connecting your transceiver to your computer's sound card for processing modes like Single Sideband (SSB) per MIL-STD-188-141 and serial phase shift keying per MIL-STD-188-110A (M110A digital data mode). 

• Internet Access: Broadband internet connectivity for official email coordination, checking net schedules, and logging into secure military web portals (such as the Apad A / official reporting platforms).

The most commonly used transceivers for MARS operations are modern, commercial off-the-shelf amateur radios that can be opened up electronically to transmit on military frequencies.

Since MARS frequencies sit just outside the standard amateur bands, nearly 99% of MARS members use standard consumer gear that undergoes a "MARS modification". Forum users across the amateur radio community widely agree on several reliable, easy-to-modify models: 

1. Icom IC-7300

• Why it’s used: This is arguably the most popular 100-watt HF transceiver in modern MARS networks due to its built-in USB sound card interface, making it perfect for the military digital data modes (like MIL-STD-188-110A) required by MARS. 

• The Modification: Unlocking the IC-7300 for wideband transmit is relatively easy and well-documented. It typically involves using a steady hand to desolder and remove a specific surface-mount diode on the main logic board.

2. Yaesu FT-710 & FTDX10

• Why they're used: Both the FT-710 and the higher-tier FTDX10 are modern, high-performance Software Defined Radios (SDR) with excellent noise filters. They are highly regarded for handling rough high-frequency band conditions during military exercises. 

• The Modification: On the amateur radio forums, operators note that the FT-710 modification is highly straightforward, often only requiring the addition or removal of a small solder jumper to expand the transmission range across 1.8–30 MHz. 

3. Elecraft KX2 / KX3 (Field & Backup Operations)

• Why they're used: For members needing a lightweight setup or low-power portable backup, Elecraft transceivers are highly valued.

• The Modification: Elecraft is highly unique because it supports MARS modifications via a simple firmware upgrade. Unlike the major Japanese manufacturers, you do not need to scrape diodes or touch a soldering iron to the board. 

4. Icom IC-718 (Budget Option)

• Why it's used: For operators looking to keep costs down, the older IC-718 is a rugged "workhorse" HF radio. Commenters on social radio groups note that pre-owned, pre-modified IC-718 units frequently circulate on the used market for under $450. 

How to Get the Modification Done

If you buy a brand-new radio, you don't necessarily have to risk soldering it yourself. Major ham radio distributors like Ham Radio Outlet (HRO) and GigaParts will perform the MARS modification for you before shipping for a small bench fee (usually around $35 to $40), keeping your core warranty secure. Some manufacturers, such as FlexRadio, will provide the unlock software directly once you present your official DoD MARS authorization license. 

How the Physical MARS Radio Modification Works

For the vast majority of high-frequency (HF) transceivers, a physical MARS modification (or wideband transmit expansion) involves removing or changing tiny electronic components on the radio's main logic board to signal the internal microprocessor to unlock the transmitter. 

• • The Hardware Alteration: Modern transceivers use a matrix of surface-mount components—typically micro-diodes or micro-resistors—to configure regional restrictions (e.g., USA vs. Europe vs. Japan bands). Performing a MARS mod requires opening the radio casing, locating the correct diode field near the central processor, and using a hot-air station or precision soldering iron to remove a specific diode or solder two jumper pads together. 

  • The Software Reset: After completing the physical change, the radio must be forced to scan its hardware matrix. Operators hold a specific key combination (such as the Power, Function, and Reset buttons simultaneously) to perform a deep factory reset. 

  • The Result: If successful, the radio reboots in an expanded mode (often reading a status like USA_MC instead of USA in the firmware menu), unblocking continuous transmission across 1.8 to 30 MHz.

Note: In rare cases, some radios (like the Yaesu FT-65R or FT-4XR) can be unlocked completely via hidden faceplate keypad combinations without opening the chassis. 

The Specialized Software Suite Required

Once your radio is physically modified, MARS operations shift completely away from standard ham radio software (like WSJT-X or FLDIGI). Because you are interfacing with military stations, you must learn to navigate a unique software suite: 

1. MS-DMT (Military Standard Digital Modem Terminal)

• What it is: This is the core software modem required to send text messages over the air.

• Function: It conforms strictly to MIL-STD-188-110A/B/C protocols. Unlike civilian digital modes (like FT8 or PSK31) which use multi-tone audio, this military modem uses a high-speed serial phase-shift keying waveform. It sounds like a loud, rhythmic rushing static or a screeching dial-up modem over the radio. 

2. Specialized Military Messaging Software

• PC-ALE (Automatic Link Establishment): Used to automate frequency selection. Operating under MIL-STD-188-141A, the software commands your radio to automatically cycle through multiple military frequencies, transmitting a brief "ping" to see which channel offers the best signal propagation to target stations.

• Text Formatting & Encryption Tools: MARS operators do not type casual chat logs. Messages must be manually or semi-automatically coded into highly rigid, formatted text blocks—often following historical ACP-127 formats—to handle emergency manifest reports, weather tracking, and secure communications. 

3. Virtual Audio Cable (VAC) & COM Port Emulators

• Function: Because military protocols require exact timing, you will need virtual audio routing software to cleanly pipe the audio from your transceiver’s USB sound card directly into the MS-DMT modem without any Windows system sounds interfering.

For military auxiliary communications, the state of California is managed under FEMA Region 9 (which covers Arizona, California, Nevada, Hawaii, Guam, and Saipan). Because exact personal names of directors change frequently due to volunteer reassignments, the military utilizes specific functional call signs and programmatic email routing. 

1. Army MARS Administration (Region 9)

California applicants and operators process their administration through the Region 9 leadership structure under the U.S. Army Network Enterprise Technology Command (NETCOM). 

• Region 9 Leadership Portal: Army MARS Support Region 9

• Key Administrative Contacts:

  • Region 9 Director: Call Sign AAD9RD

  • Region 9 Executive Officer: Call Sign AAD9RX

  • Region 9 IT & Signal Officer: Call Sign AAD9R6 

• Mailing Constraint: HQ Army MARS explicitly states that their facilities are not serviced by standard US Mail. All physical applications or inquiries from California must go through the U.S. Army Ft. Huachuca NETCOM Mailbox electronically via usarmy.huachuca.netcom.mbx.mars-hq@army.mil. 

2. Air Force MARS Administration (Region 9)

Air Force MARS processes applications through regional managers who assign individual state mentors to applicants.

• Contact Directory: General management inquiries can be routed directly to the Air Force MARS Hub at afnic.mars@us.af.mil.

• State Processing: Once an application is submitted, a dedicated California State Flight Leader or Region 9 Director will contact you to assign a training mentor.