Most of the documentation on the VIC-1 equipment is in the VRC-12 Series Radio manuals so I have combined them on this web page.
Since the MT-1029 Mount, which is a part of all VRC-12 series radio systems, is also used with other radios it's on a seperate web page that also has information on the VINSON compatable versions of the VRC-12 system.
FFCS boxes are more intelligent and have their own displays. The big push for the VIC-5 system is that it also supports Ethernet for VOIP - C. Alexander Leigh
This section on the VIC-3 was updated with the help of Mike Murphy. VIC-3 supports Active Noise Reduction (ANR) headsets.
The power supply is the standard military vehicle 24 VDC (18 - 22 VDC) and can draw up to 2.6 Amps depending on the system configuration.
The interface between stations is digital Biphase modulated at 2.56 Mbps, 10 Vpk-pk (max, 2 Vpk-pk (min).
The field wire interface is compatible with the VIC-1 AM-1780 and TA-312 analog field phone.
The radio interface is compatible with the SINCGARS (SINCGARS, RT-1439, RT-1523), GRC-213, VRC-12.
The VIC-3 does not use 2-conductor wiring. The highway cables (between the FFCS and MCS) are 7-wire. The cables between the MCS and the radios are 6-wire. Also, the system is not digital. The audio is analog as with the VIC-1. Digital signalling is used to carry PTT and mode select messages, but the audio is analog. The system is "programmed" to know its topology so if a station is missing or an extra one is added the MCS can display an error.
The audio transmitted between the FFCS crew boxes is indeed digital. That is how audio permission for each radio can be applied to each crew station. There IS a wire dedicated to analog audio in the highway cable and this is only used by the MOS monitor only stations. Why they decided to do it this way is of course a mystery.
TM 11-5830-263-20&P has a very useful description of the cable construction and box operations.Cam
22 May 2017
Some other tidbits that you might want to mention are the fact that the U228 connectors on the FFCS carry power on the extra pin. I believe this is the pin that is used for fill in single-port SINCGARS radios. The purpose of this is to power the ANR units in the Bose headsets which are intended for this system. However, other radio accessories that are normally compatible with single-plug U228 work, eg, H250, peltors, etc.
The VIC-3 can be configured in either a ring configuration or a branch configuration. In the former the FFCS boxes are connected in a ring to the MCS. This allows the system to keep functioning if a cable or FFCS breaks, which it will detect (the MCS displays the fault).
Unlike the VIC-1, the VIC-3 MCS cannot parasitically take power from a radio. It needs to be powered from the power port. The MCS has provisions for 2 radios, and then 4 more can be added via a pair of RIT boxes - the system is full at 6 radios.
The VIC3 is also known as the ROVIS. The hardware is the same - it is compatible - but the ROVIS is the "export" version. There is another flavor of ROVIS called the LV2. In this system the MCS is doubled up with a FFCS (and the same small size as a FFCS). This allows the system to be installed in a much smaller footprint, ideal for smaller vehicles like ATVs or Jeeps.
Another tidbit which people seem to run into is the power. The cables goes to a radio tray same as a VIC-1 and is that big 4-pin connector. On the VIC-3 though the pinout is "backwards". A carries +24V and B carries GND. What throws people off is GND is floated to the regulator whereas the shell of the connector is the chassis ground. So the correct wiring is +24 to A (WHITE) and GND to B (BLUE) AND SHIELD. Thankfully the MCS Is reverse polarity protected.
VIC - Vehicle Intercom System
FFCS - Full Functional Crew Station
MCS - Master Control Station
PTT - Push To Talk
SINCGARS - Single Channel Ground / Airborne Radio System
U228 - Military Standard Radio Headset Connector
ANR - Active Noise Reduction
ROVIS - Royal Ordnance Vehicle Intercom SystemLV2 - ???
- C. Alexander Leigh
Photos of VIC-3 Installation in LMTV truck (Wiki).
TM 11-5830-263-20&P starting at pdf page 150 labeled A to V.
App H, pdf page 223 Connector Pin ID & Signal Names.
Note the 4-Pin Power plug has standardized wiring that goes back to at least the MT-1029 - CX-4720 cable:
Black & Green Negative B
Red & White Positive
maybe gnd for On
Power COnnector Inc. 18-708 OCS66 0136
Connector P2 mates with power connector on radio mounting tray
Cable Assy - Pwr. Elec p/n A3206017-7 Date - 10/01
Connector P1 mates with MCS Power Connector
PCI 18-187N OCS66
Connector P1 mates with Station connector
CX-13470/VRC(10 feet. 0 inches) W15P7T-06-F-0029 Mfr 65242 NSN 5995-01-406-1171
Cable assy - Spcl Prp. Elec pn A3206018 - 10 Date - 04/07
Connector P2 mates with Station Connector
PCI 18-187N OCS66
Highway Cable A3206018
Always P1 to P2 the 7 pins are wired 1:1.
This system can continue to operate even when there are certain types of failures, like a cable being severed.
MCS CD-82/VRC Master Control Unit
Fig 3 Test Fail
The Power connector is marked: AB05 1002PC 34A5872 ABM0829
TT Electronics AB05 connector datasheet (ab05-951972.pdf) decoded:
10: cable connecting receptacle
FFCS C-12357 Full Function Crew Station
MOS C-12358 Monitor Only (Crew) Station
RIT C-12359 Radio Interface Terminal
LS LS-688 Loudspeaker
TF 11-3305 Radio Set AN/VRC-12, 1963 - RT-66, RT-67, RT-68 are replaced by VRC-12 which consists of: RT-246, RT-524, R-442Legacy radio system retired from Army Guard
Nov 20, 2008
BY Staff Sgt. Jon Soucy
ARLINGTON, Va., (Army News Service, Nov. 20, 2008) -- After more than 50 years in service, the venerable AN/VRC-12 series radio was retired from the Army National Guard in a ceremony Nov. 18 at the Army National Guard Readiness Center.
For many, the retirement is symbolic of many other changes that have taken place within the Guard over the past few years.
"This is really a symbol of us transforming to an operational force," said Maj. Tony Caldwell, the Army National Guard battle command team chief. His team oversaw the phasing out of the '12'-series radio systems.
First introduced in the 1950s, the 12 series radios were used extensively in Vietnam and retired from the active component in the late 1980s in favor of the Single Channel Ground and Airborne Radio, more commonly known as the SINCGARS, said Caldwell.
The 12 series radios were still common in the Guard and Reserve in 1991 during Operation Desert Storm. And for those called to active duty for that conflict, once on the ground in the Middle East, communications became a problem.
"It was difficult for those with the older radios to talk with those using the SINCGARS," said Caldwell.
Throughout the ensuing 17 years since the Gulf War, the SINCGARS radio was phased into the inventory of Guard and Reserve units, but it wasn't until recently that all remaining 12 series radios were replaced, said Caldwell.
The replacement of the radios also represents a change in the way units are supplied with equipment.
"There's been a real change in the last few years and if you hadn't been around before, you wouldn't appreciate it," said Col. Harold Greene, deputy director for material at the Department of the Army.
In the old system, there was a tiered readiness level with certain units getting newer equipment first, said Greene. "I can tell you absolutely, today, we don't do that in any of the components."
Now, said Greene, units are equipped based solely on their Modified Table of Organization and Equipment, the document that lists out what equipment and people and how many of each units should have, regardless if the unit is active or reserve component.
"Certainly, as we go through deployments in support of the Global War on Terrorism, we don't distinguish between components in how we use those troops (in those units)," said Greene.
The SINCGARS has many improvements over the 12 series radios such as a greater range, greater battery life and the ability to hop between frequencies, which results in greater security of radio transmissions.
But, for many, the 12 series will always occupy a certain place in their heart.
Brig. Gen. Leodis T. Jennings, special assistant to the director of the Army National Guard, said his greatest memory of the 12 series radio was using it while attending the Primary Leadership Development Course as an E-4 at Fort Lewis, Wash.
There, students used 12 series radios as they rotated through positions in a squad while on patrol.
"It (radio operator) got to be the position I hated the most," said Jennings. "Every time the patrol leader did something or went somewhere you came running with this radio on your back and you would hand it to him and it didn't work. And he would say, 'What have you done to the thing?'
"And, I don't recall ever doing anything to it. More often than not it didn't work. You were carrying extra batteries and it was heavy. I don't know how long the batteries were supposed to last, I think we were told eight hours, but if you had one that lasted two hours you were doing good." (Brooke: Note this is not correct the VRC-12 radios are NOT man portable!)
Short battery life and a penchant for overheating are things that stick in the minds of many who remember the radios, said Caldwell, who as part of an artillery unit used to have his Soldiers place wet sandbags on top of the radio units to help keep them cool.
Despite those obstacles, Guard members still met the mission. "Even though this was a capable piece of equipment, it was not the best radio, but we in the Guard made it work," said Jennings.
And for those currently serving and using outdated equipment, Greene says be patient.
"Hopefully, we've now set the system up so that it won't be these relics of the past, of my past as a young officer, that hang on out there in the farthest reaches of the National Guard. And that we've got everyone modernized ... across the entire force," said Greene.
(Staff Sgt. Jon Soucy writes for National Guard Bureau)
another link to the same file in two parts.
Radio Set AN/VRC12 pt1-2 1963 US Army Training Film
Radio Set AN/VRC12 pt2-2 1963 US Army Training Film
The "VRC-12 Series" of radios is is the shorthand way of saying each of the following vehicle radio set names. These radios are supposed to have an annual alignment Ref June '94 PS mag 499 pg 5 and TM 11-5820-401-20-1 Paragraph 3-5.
VRC-44 VRC-45 VRC-46 VRC-47 VRC-48 VRC-49 VRC-53
I've shown the VRC-53/GRC-125 (PRC-25 based) and VRC-64/GRC-160 (PRC-77 based) systems in the table but they probably are not technically part of the VRC-12 series.
All of the above radio systems make use of either the MT-1029 large Mount or the MT-1898 Mount for the R-442 receiver.
These radios came out about the same time as the PRC-77 and included provision for X-Mode operation, which at introduction was by means of the Nestor KY-8, KY-28 or KY-38 Secure Voice system, later the VINSON system was used with the VRC-12 series radios where the KY-57 was the common Transmission Security Device.
The RT-524 or RT-246 or AM-2060() all mate with the MT-1029 Mount.
Both the RT-524 and RT-246 when used by themselves can only operate in half duplex mode, that is Push and hold to talk, release to listen.
RT-524This radio is about the same physical size as the AM-2060 with either a PRC-25 or PRC-77 mounted. It is a single channel radio with frequency setting using controls very similar to the PRC-25 or PRC-77. It has a built in speaker. The power output can be either __?__ or 30? Watts, considerably more than the output of the PRC-25 or PRC-77 which are only a few watts. But note this extra power only comes into play when the vehicle is sited on a hill or an external antenna like the RC-292 or OE-524 is used.
RT-246This radio uses many of the same internal modules as the RT-524 but instead of a speaker it has push buttons for selecting one of 10 preset operating frequencies. The physical size is the same as the RT-524. This radio allows remote selection of the operating frequency using one or more C-2742 Remote frequency control boxes.
R-442This is a receiver only referred to as the "auxiliary receiver". As shown in the table above it's a part of a number of the VRC-12 Series radio systems.
Capability of the various VRC-12 Series systemsThe following systems contain only a single RT: VRC-43, VRC-46, VRC-53/GRC-125 and VRC-64/GRC-160. These systems can only be used in half duplex mode.
Systems with at least one RT and either one or two Aux receivers: VRC-12, VRC-44, VRC-45, VRC-47, VRC-48, and VRC-49 can be used in the full duplex mode which is just like a telephone where you can speak and hear the other person at the same time. There are restrictions concerning seperation of operating frequencies and distance between antennas for this to work. This is not to say that these systems were used that way, just that it's possible.
The VRC-48 and VRC-49 systems contain both the AM-1780 and C-2299 and are designed for retransmission opertion and need to obey the same rules about frequency and antenna seperation.
X-ModeThe X-mode connector on the VRC-12 series radios is NOT the same mechanically as the POWER connector on the PRC-77. The jumper cap must be in place for plain text operation since it has 3 jumpers.
X-mode in (Rx)
X-Mode Out (Rx)
150 Hz Tone in
X-mode in (Tx)
X-mode out (Tx)
150 Hz Tone out
A to C
D to J
E to G
The following manuals include VIC-1 onfo, but are not specific to the VIC-1 system.
VRC-12 Series & VIC-1
TM 11-5820-401-10-1This is the operator's manual for wheeled vehicles Radio Sets: AN/VRC-12, ... AN/VRC-49 where the interphone system is typcially not used. It does include the use of:
TM 11-5820-401-10-1HRThis is the Hand Receipt manual for wheeled vehicles. It's 102 pages with information on which install kits are used for which radio in which vehicle.
TM 11-5820-401-10-2This is the operator's manual for tracked vehicles Radio Sets: AN/VRC-12, ... AN/VRC-49 where the interphone system is typically used. It does include the use of:
- AM-1780 and all the above VIC-1 boxes.
TM 11-5820-401-10-2HRThis is the Hand Receipt manual for tracked vehicles. It's 296 pages with information on which install kits are used for which radio in which vehicle.
TM 5820-401-20-1Is the organizational Maintenance Manual for wheeled vehicles. 384 pages with lots of details.
TM 5820-401-20-2Is the organizational Maintenance Manual for tracked vehicles. 637 pages with lots of details.
Para 1-26 & 1-27 have a lot of VIC-1 theory
TM 5820-401-34-2-1 & TM 5820-401-34-2-2Are the Direct Support & General Support Maintenance Manuals for the RT-246() and the RT-524() Radios
TM 5820-401-34-2-3Is the Direct Support & General Support Maintenance Manual for the R-422()
TM 5820-401-35-1Is the Direct Support, Gen Support & Depot Maint Manual for the C-2742 10 channel remote frequency control of the RT-246 and the C-2299 Retransmission box.TM 11-5820-401-35-7 Control, Intercommunication Set, C-2297/VRC
TM 11-5820-401-35-9 Mountings MT-1029 & MT-1898
TC 11-4 Handbook for AN/VRC-12 Series of Radio Sets - April 1977 Training Circular includes use of VIC-1 Boxes
VRC-53/GRC-125, VRC-64/GRC-160 ManualsTM 5820-498-12 Chapter 6 has some VIC-1 equipment info.
VIC-1 SpecificTM 11-5830-340-12 Intercommunication Set, AN/VIC-1(V) and Control, Intercommunication Set, C-10456/VRC
TM 11-5830-340-23P Intercommunication Set AN/VIC-1(V)
TM 11-5830-340-30 Intercommunication Set AN/VIC-1(V)
TM 11-5820-898-20P Amplifiers Audio Frequency AM-1780A & AM-1780B
TM 11-5895-1548-34 Audio Frequency Amplifier AM-1780B/VRC (NSN 5895-01-284-3057)
TM 11-5895-1548-24P Amplifier, Audio Frequency AM-1780B/VRC (NSN 5895-01-284-3057)
TB 11-5820-890-20-44 Installation Kit, electronic Equipment MK-2382/VRC (NSN 5895-01-330-5580) (EIC: N/A) to Permit Utilization of the AM-1780/VRC in U.S. Army in Conjunction with MK-2347/VRC (AN/VRC-89/91/92 SERIES)
VIC-1 related Install KitsTB 11-5820-890-20-44 - Mk-2382 Army Watercraft with VRC-89/91/92 SINCGARS radios
TM 11-2300-361-15-4 - VRC-12, -46, -47, -53, & GRC-125 in M60 Tank w/ 105mm Gun
TM 11-2300-364-15-1 - VRC-46, -53, & GRC-125 in M48A2 based Bridge launcher