USMC Field Radio Operator (MOS 0621) Job Description

The Field Radio Operator (MOS 0621) is a versatile Marine and can be utilized in any unit in the Marine Corps such as the following:

• Engineering
• Artillery
• Infantry
• Tanks
• AAV – Amphibious Assault Vehicle
• Headquarters
• Communications
• RECON/MarSOC

The Radioman will not be an infantryman or a tanker, but if assigned to those units, he will be fighting side by side with the members of those combat units and carrying a radio or operating the vehicle-mounted radio. Some select radiomen will get assigned to go out with the infantry companies and will be responsible for the communications in that company. However, in the larger communication units, the radioman will be with other radiomen and fellow communicators.

Where Training Begins

Marine Corps Communication-Electronics School (MCCES) in 29 Palms, California (Marine Corps Air Ground Combat Center) is the location for training the majority of the USMC communications and air/ground electronic maintenance Military Occupational Specialties (MOS) to include the Field Radio Operator MOS 0621.

The mission of the Marine Corps Communications-Electronics School is to train Marines in ground electronics maintenance, tactical communications, and air control/anti-air warfare operations and maintenance to ensure that Marine commanders at all levels can exercise command and control across the full range of military operations.

Tactical Communications Training School (TCTS)​ (Company B) is the school that the Field Radio Operators MOS 0621, as well as others in the 06xx MOS field, receive their training. Company B is responsible for training communications systems operators. 

The main job of Field Radio Operators is to employ radio to send and receive messages. Typical duties include the setup and tuning of radio equipment, including building and repairing antennas and power sources. The Field Radio Operators number one responsibility is to establish contact with distant stations and process and log messages. The Radio Operators also receive training in communications security (COMSEC) and are capable of making changes to frequencies or cryptographic codes. As the Field Radio Operator advances in rank and experience, the next progression training for Staff Sergeant through Corporal is Radio Supervisors Course.

USMC Radio Operator MOS 0621 Job Requirements

ASVAB: Must possess an Electronics Repair, Missile Repair, Electronics and Communications (EL) score of 90 or higher.

• Complete the Field Radio Operator Course
• Must possess a valid state driver's license
• Must be a U.S. citizen
• Must have a secret security clearance
• Rank Range: Sgt to Pvt

Types of Radios

The Field Radio Operator is skilled in the long list of radios for all frequency ranges and uses. The radios used are divided among the frequency range as well as for their specific uses. The ranges are ultrahigh-frequency (UHF), and upper very high frequency (VHF) and high frequency (HF) transmission radios.

HF Radios Used By The Marine Corps

The following radios are commonly used by the Radio Operator as the primary advantage of using HF radio is its capability to provide long-range, over the horizon (OTH) communication.

• AN/PRC-104
• AN/GRC-193
• AN/MRC-138
• AN/TSC-120

VHF Radios Used By The Marine Corps

SINCGARS family: SINCGARS is the standard VHF-FM tactical radio for the Marine Corps. The system provides high security against threat electronic warfare (EW) by using frequency hopping with integrated COMSEC.

• AN/PRC-68
• AN/PRC-119
• AN/VRC-88 (A, D)
• AN/VRC-89 (A, D)
• AN/VRC-90 (A, D)
• AN/VRC-91 (A, D)
• AN/VRC-92 (A, D)
• AN/GRC-213
• AN/VRC-83

Certain units may require that the Radio operators use various commercial off-the-shelf (COTS) VHF radios. Typically, these radios have been purchased by the units and are not part of the official Marine Corps table of equipment. Smaller unit and front-line combat units like some infantry units, RECON or MarSOC, will use these person-to-person radios.

UHF Radios Used By The Marine Corps

UHF transmissions may also be used in long-range satellite communications, increasing ranges to thousands of miles transmitting both two-way voice and data transmissions.

• AN/PRC-113
• AN/VRC-83
• AN/GRC-171
• AN/PSC-3
• AN/PSC-5: The AN/PSC-5 is the primary DAMA-capable, TACSAT radio available to the MAGTF. TACSAT limitations include the competition for available frequency resources and channel time on the satellite.

Marine Corps UHF tactical SATCOM system supports and augments the high precedence command and control and common-user, single channel requirements of a Marine air-ground task force and its major subordinate headquarters.

• USMC Radio Operators Handbook
• MCRP 3-40.3B
• FMFM 3-36

Antennas

Learning the large variety of antennas for each radio, creating field expedient antennas, and mending broken antennas is another part of the USMC Radioman’s education.