I am in the final stages of completion of a M151A1 belonging to the S3 section of 2d Battalion 47th Infantry (Mechanized) of the 9th Infantry Division in Vietnam in 1967. I am getting ready to wire in the radio and I have a couple of questions. Would the AN/VRC 47 or the AN/VRC 46 be the correct radio set? If the AN/VRC 47 is utilized, does it require the use of two separate antennas? I have a wiring diagram for the AN/VRC 47 and it appears to call for two antennas. If so, where would the second antenna mount be located? The picture I am going off of only has one antenna mount and a very obscured view of a radio, but not enough is showing to determine which one.

Thanks for any insight as my experience with radios is with the AN/PRC 77 w/KY-57, AN/PRC 104, PSC-3 SATCOM, SINCGARS, ASIP, PSC-5D, and PRC-152 as a ground pounder. I am familiar with the wiring of some of the more modern radios into Humvees and MATVs, but that is about it.

Cheers,
James

HAVING BEN IN AN MP BATTALION HQ'S IN THE EARLY 70'S THE COLONELS VEHICLE HAD THE ANVRC46/47 SETUP. THERE WAS DEFINATELY 2 ANTENNA'S THE STANDARD ONE ON THE RAER CORNER AND A SMALLER ONE ON THE REAR QUARTER PANEL I DON'T REMEMBER WHICH SIDE.

Thanks Steve.

A friend of mine sent me a picture of the secondary or auxiliary antenna and it is located on the passenger side in front of the rear wheelwell on the outside behind the passenger seat.

It seems like an odd place, but if the antenna is kind of short, I guess it wouldn't be much of an issue for the crew.

Take care and have a great day.
James

My thought is that a battalion ops jeep would have a dual rig – an AN/VRC-46 on one side and an AN/VRC-47 on the other. Three nets, three antenna. Like this one- not Viet Nam, but same equipment. my 2 cents - hope I can make the pic work

crud - I seem to be e-challenged this evening -anyway, I uploaded a couple of pics of the rig I was trying to describe into my gallery here at armorama if you're interested

Thanks, Don.

It does make sense for and S3 vehicle to have the dual rig like there are in those pictures. Thanks for sharing those photos. They are a big help.

Cheers,
James

If two large spring based whip antennas are used one goes on each rear corner - the mounting brackets are reversible just for this purpose.

They are right, the short (half lentgth) antenna with a ceramic or rubber base is usually mounted on passenger side, sometimes angled backwards on a small mount between the rear wheel and the front seat so that the antennae wire just goes right through the side and into the passenger compartment near the radio.

Don't forget to run the power cable to the radios - goes along the inside edge on the passenger side from the battery box under the passenger seat. If a radio is used on the drivers side, there's a metal channel that bolts to the floor and the wire goes under that.

James & AJ
I spent my "formative years" in the 11th ACR and 9th Infantry Division in the 70s. Later on I spent time in the 25th and 2nd Divisions in the early 80s. The photo AJ provided shows three radios, but only two are "transceivers". Given the date of the photo they are likely ANVRC 47 transceivers, with an RT442 Aux radio, although they could be a 47 with an ANVRC 12 set (commonly found in commander's and S-3's vehicles). The ANVRC 12 would have used an RT 246 push-button transceiver which could be pre-set to whatever channels the commander wanted (I forget the number, but I think it was 6 pre-set frequencies). With the 46/47 you had to change the frequency manually on a dial. For sure there are three radios in the photo--hence three antennas-- if you look beyond the helmet you can see the third radio behind the drivers seat, but it's difficult to tell what type it is-- its large enough to be a 47 or RT246 (which would make the set an AN/VRC 12). The small antenna with the brown (ceramic) insulator is for the Aux RT442 radio, which is only a receiver. You can see the small Aux RT442 alongside the large radio behind the passenger seat. The combination of radios allowed commanders and S-3s to talk on multiple nets and monitor 1 net simultaneously. As a company commander I had an ANVRC 12 set up because I commanded a Smoke Generator company with 64 gun jeeps and 128 smoke generators supporting a Division (the company had more firepower than an infantry company)-- I had to monitor and talk on my own company net, and be prepared to talk on two supported unit nets. In simplistic terms, what I usually did was set the aux receiver to the primary supported unit net and programed the same frequency into the VRC 12 so if they called me I could quickly push a button and respond on the RT246 (VRC12). I would also program frequencies into the RT246 for logistics units supporting my company, and my senior commander, so I could switch frequencies rapidly if I needed to talk with them. I would always keep the 47 set on the company frequency so I could monitor and talk with my platoon leaders.
Very Respectfully, Russ Bucy COL, USA (Ret)

Thanks to everyone for their responses and input.

Russ, I appreciate you explaining how you had your radios set up and it helps a lot. I think I will be configuring the radios for this model similar to yours.

Take care and have a great day.
James