Radio Platform Vehicles

This is where information for all radios beyond the simple mass produced RT series of radios lies. So this page does not cover the RT 66, 67, 68 series in the early M151 and the RT 524 / 246 & PRC-77 series from the mid 1960 to the late 1980s when the M151 series was being phased out.

Many of these M151s would of had 100 amp charging systems installed. Pictures of this will be updated soon. What is a "sponson" mount. This is the specific adapter bracket between the vehicle (and its specific shape or ???) and the mount (specifically made for the radio) that the radio or radio assy sits in.

All Collins Factory photos from reference library, and were captioned by the late Dave Ross. Thanks go to Brian Bjerkelund, k7ais, for allowing us to present this information. 

Some of the Radio Sets covered in the section below:

AN/GRC-19 Radio Set

TLQ-17A Radio Set

AN/GRC-106 Radio Set

AN/VRC-80 Radio Set

AN/VRC-81 Radio Set

AN/PRC-47 Radio Set

AN/MRC-83
Radio set, Vehicular, Mounted on a M-151 jeep, 2-30 MHz, 1 KW, AM, SSB, CW, Consists of R-761, T-730, C-3341, CU-749, C-2848, AM-2306 and CV-786, Collins Radio 

AN/MRC-107 & 108

AN/MRC-109 & 110

AN/MRC-119 & 120 (AN/MRC-85)

AN/MRC-138

 
PRC-105, PRC-515, VC-120 & other ManPack or....Non-standard Radio Sets Jeep mounted 

Angry 19 - I have yet to find pictures or manuals for this set that pertain to the M151. I do have 2 original steel "sponson" mounts that are 100% for the M151 series vehicles and has the mounting holes for the MT-851 (the holes line up). The MT-851 is the mounting base for the AN/GRC-19 radio set.

This picture to the right is in an M38A1 but would have been the same set up in an M151. Publicity photo of a complete MRC-83 radio set, a TRC-75 installed in an M38A1 jeep. Visible underneath the radio is the power supply box carrying the PP-2352 inverter - the inverter runs off 28VDC and makes 115 VAC 400~ 3 phase power for the radio. On the front of the power supply box are controls for the inverter and also a rudimentary selftest setup for the inverter with lamps to give a go-nogo indication as to the health of each chopper transistor in the inverter. The MRC-83 first saw the light of day around 1960 - in those days it was quite a feat to put a 1kW automatically-tuned HF radio in a vehicle. I saw over 2000 TRC-75 radio sets come up for disposal at DRMO Barstow in the early 1990s, and I guess that most of those radios were installed in M38A1 jeeps just like this one - the 1960s was an excellent time to own stock in the Collins Radio Corporation. Credit Jim Stitzinger’s 

 GRC-106 400W SSB Synthesized HF Transmitter - Receiver
The GRC-106 is a Fully Synthesized 400 Watt HF SSB mobile vehicular Receiver / Transmitter Radio Station operating on CW and USB, 28 000 selectively tuned channels spaced in 1 KHz increments in the 2 to 29.999 MHz providing full coverage from 2 to 30Mhz frequency range.

The Radio station consists of two major units that are the Receiver / Transmitter, Radio RT-841/GRC with 100 Hz steps and the HF Amplifier, Radio Frequency AM-3349/GRC 106.

Vernier tuning +/- 500 Hz which allows the receiver section to be continuously tuned over the entire frequency range. The frequency stability is excellent at 5 parts in 10/8 in 24 hours of operation. The Receiver First IF 20 or 30 MHz, Second IF 2.85 Mhz and the Third IF is 1.75 Mhz. Bandwidth is 3.2 KHz which is derived from the crystal filter. Receive sensitivity is less than 0.3 microvolt for 10db signal to noise ratio.

The Transmitters output power is 400w PEP on SSB and compatible AM and 200w average on CW and FSK. Transmitting range is 50 miles with whip antenna and 1000 miles with doublet antenna.

The station operates from 24-28 VDC @ up to 50A in full power transmit mode. The receiver section requires only 1A at 24VDC to operate.

Manuals related to the GRC-106 and installation

TM 11-2300-351-15-1   -   Installation of GRC-106 in M151 Series (Not very informative)

TM 11-5820-520-12   -   Operator & Organizational Maintenance AN/GRC-106

TM 11-5820-520-20   -   Organizational Maintenance AN/GRC-106

TM 11-5820-520-20P-2   -   Organizational Maint. & Repair Parts AN/GRC-106A

TM 11-5820-520-34P-2   -   Direct Support & General Support, Repair & Special Tools

TM 11-5820-520-34P-3   -   Direct Support & General Support, Repair & Special Tools

This series of radios is very hard to verify what is what. The 107 & 108 are different but similar. They also went through many upgrades over the years. So some of the pictures and references may be confusing. I honestly have a big gap of good understanding with these sets.

H.F. Transceiver was a AN/MRC-95   by Collins Model Number 618T3,  718F-1 coffin, 313V-1 control head, 618T-3 radio, 426T-1 power   inverter, 460D-1 load coil, 670D-1 tuning coil,  76F-3 speaker.    The HF Antenna was 32 feet tall mounted with a rubber boot for protection to   people passing by so that they would not receive RF Burns.  This   antenna reduced to 10 sections the width of the jeep. This antenna is a   Shakespeare 120 HF Antenna, NSN: 5985-00-846-6442 Military nomenclature:   AT-1011/U  and is still available from the factory in South   Carolina.

UHF   Transceiver was a AN/ARC-51BX, 718F-1 coffin,  313V-4 control head, ARC   164 or ARC 51BX radio, 76F-3 speaker.  This antenna was shared with the   VHF antenna. This antenna was just behind the passengers seat. This   antenna was what is called a dual band antenna with VHF in the lower portion   and UHF in the upper section.  This antenna had separate RF feed lines.

VHF   Transceiver was a Collins Model Number 618M, same coffin as UHF, 313V-3   control head, 76F-3 speaker. This radio shared the UHF antenna. This antenna   was just behind the passengers seat. This antenna was what is called a   dual band antenna with VHF in the lower portion and UHF in the upper   section.  This antenna had separate RF feed lines.

FM Transceiver was a AN/PRC-25 and   a AM-2000 Power Amplifier (RT-254?)  This radio had its own antenna about 15 foot long   mounted on the left rear corner of the jeep looking from the front to   rear.

Secure   Voice System AN/KY-38 not found on the MRC-107's which were newer.

Portable   Back Packs were a AN/PRC-47 (HF) and AN/PRC-25 (FM) units

The   Jeep was a M-151 Military (Ford Motors) Jeep and was modified for this gear   including engine, generator, cooling system, and seating. This jeep was very   tipsy and could roll over on a dime.  You did not get in a hurry in it   if you wanted to live!

The   Trailer was used to carry our supplies below the Generator which was mounted   sideways across the top of the trailer above the Axle for weight   control.  Spare fuel was found only on the tail end of the trailer, not   on the jeep due to high RF fields.  Generator Voltage was 115v, AC   400cps

AN/MRC-109 is the same components as the AN/VRC-47

• Antenna AS-1729/VRC
• Receiver Radio R-442
• Radio mount MT-1898
• Receiver-Transmitter RT-524
• Radio Mount MT-1029
• Coder- Decoder KY-38
• Handset H-189
• Headset H-140
• Loudspeaker LS-454
• Microphone M-80
• Plus related cables, brackets, bolts, etc...& "Junction box assy AN/MRC-109"

AN/MRC-110 is the same components as the AN/VRC-46

• Same as above - Minus R-442 and related components

The original USMC manuals show an fairly large extra box (junction box) on the drivers side fender across from the radio on the passenger side. Also on an example I own (09-1965), the battery box contains a special power junction box and power cable assy. I believe all these "extra" components were on the early M151A1s using the "new" RT-524s & R-442s only. 

The AN/MRC-119 & 120 are a combination of truck and trailer.

AN/MRC-120 consists of:

   Radio Set AN/MRC-95 Mounted in M151 Series Truck 

   Radio Set AN/VRC-46 Mounted in M151 Series Truck

   All related antenna, cables, mounts and related

AN/MRC-119 consists of:

   Radio Set AN/PRC-25 Mounted in M416 Series Trailer

   Radio Set AN/PRC-41 Mounted in M416 Series Trailer

   Radio Set AN/PRC-47 Mounted in M416 Series Trailer

   All related antenna, cables, mounts and related

TM 11-5820-696-15   -   Org. & Dept Maintenance Jeep mounted

TM 11-5820-514-15   -   Org. & Dept Maintenance Radio Set AN/MRC-95

Future Information

Future Information

Description & Purpose: The Radio System is a rack mounted tactical communications system. The Radio System is packaged for mounting in the ,M-151Al/A2 (M-151) 1/4 ton utility vehicle, or the M-113-A1/A2 (M-113) Armored Personnel Carrier (APC) When the Radio System is installed in the vehicle (M-151 or M-113) it may be operated as a stationary or mobile communication facility. Both Radio Communication Systems, AN/GRC-206(V)1 (fig. 1-1) and AN/GRC-206(V)2 (fig. 1-2) incorporate HF-SSB, VHF-FM, VHF-AM and UHF-AM subsystems, and associated electronic equipment to provide radio communication capabilities, in three communications bands. Radio Communication System AN/GRC-206(V)1, also provides all the mechanical and electrical interfaces (e.g. equipment mounts, cables, etc. ) necessary to install and operate user supplied communication security (COMSEC) equipment. The Radio System is intended for use by Tactical Air Control Parties for tactical ground-to-ground and ground-to-air communications, and by other Tactical Air Control System (TACS) elements with similar requirements. 

 ELECTRICAL DESCRIPTION. The Radio System can be operated as a mobile or fixed tactical communication station. Primary power (+22.5 to +30.0 Vdc) for the Radio System is supplied by either of two sources: the vehicle (M-151 or M-113) electrical system during mobile operations; or an auxiliary motor generator (e.g. MEP025) during stationary (fixed) operations. In addition, the Radio System is equipped with a power selector switch which allows the Radio System to be operated from the vehicle batteries for a short time should the main power sources become disabled. The Radio System provides the following communications capabilities: a HFSSB subsystem, operating in the 2.0000 through 29.9999 MHz range; a VHF-FM subsystem, operating in the 30.00 through 75.95 MHz range; a VHF-AM subsystem, operating in the 116.000 through 149.975 MHz range; and a UHF-AM subsystem, operating in the 225.000 through 399.975 MHz range. Separate control and simultaneous operation of the above capabilities is possible, limited only by certain frequency combinations prone to interference, and communication security restrictions. A signal distribution unit (SDU) is used to interface the four subsystems with one or two radio set controls (RSCs) The RSC/SDU interface allows complete control of the Radio System (through the use of local and remote cables) from local or remote locations. Local emergency operation is possible by bypassing (removing system interconnect cables from any subsystem) the RSC/SDU interface, and controlling an individual subsystem by its front panel controls. 

 The M-151 is a 1/4 ton utility vehicle with a 100-ampero alternator capable of supplying primary power for the Radio System. With minor modifications, the vehicle provides space and facilities to mount the equipment mounting rack, one RSC, and three antennas. It also provides stowage space for optional antennas (and antenna segments) and cables. The M-416 trailer must be used with the M-151 vehicle to stow ancillary items supplied with the Radio System. 

This is the section for stuff I can't identify or only have 1 or so pictures of. If you know what something is or any information please share it with me.