AN/VIC-4, and adding switched 12V/24V to the M35

Here's some info on how to rig up your own sources of 12VDC and 24VDC which are switched by the vehicle's main power switch and include a battery equalizer. Also shown is the VIC-4 intercom system about to be installed. Contact me if you want a schematic fo the power arrangement.
http://www.bunkerofdoom.com/mil/m35/vic4/index.html

Thats a VIC-1 Intercom System.

Are you sure? Look at the control boxes and the extra switches, this system handles four tranceivers where the VIC-1 handles two tranceivers and two receivers. The inside of the amplifier is quite different as well and my NSN's are not VIC-1 NSN's.

NOTE: I added the 24V/12V schematic to the web page now.

Well, its not the VIC-1, and I never heard of a VIC-2 in years the Army. We did have the VIC-3, but that had some digial displays on the main IC station, those were on the new M1A2's and M2A2ODS's and up... I'll have to research it a bit.

OK I don't want to cause confusion over the model number, so until someone can definitively identify it, I'll use "quotes" and call it a "VIC-4".

The "VIC-4" (apparently VIC-4) I have here is not simplified but modernized. The PC board shown in fact contains most of the circuitry in a single potted block. Ribbon cables connect that board to the jacks all the way around. The power supply module is separate and is attached to the inside of the case to dissipate heat. The comparison of the "VIC-4" over the VIC-1 I have noticed so far are:

VIC-1
1. Control of two trancievers and two receivers.

2. Ability to listen to "all", or "any one" tranceiver or receiver at a time.

3. Possibly easy to repair.

4. External retransmit box required.

VIC-4
1. Control of four trancievers.

2. Ability to listen to any combination of tranceivers simultaneously.

3. Difficult to repair, unless you have spare circuit board.

4. Integrated retransmit function.

I don't want to get into arguments about what model it is since I am no expert on them and so much has been said that it could be a VIC-1 of some kind. The dealer who sold it to me told me it is a VIC-4, and he has never been wrong about model numbers before. It's definitely not a VIC-3.

The amplifier unit has no AN/ number on it. The VIC-1 manual shows a control box C-10680/VRC which does look like the boxes I have. It also mentions but does not show an AM-7046 amplifier, which it says is a rewired AM-1780 and says that it can control three tranceivers. A picture of the inside of the AM-7046 with PCB part numbers might lend a clue.

The AM-7046 is used as part of a VIC-1 in the "Interim Fire Support Team (IFIST) vehicle M113A1" -any M113 crewmembers here?

Please see the inside of the amplifier in my posession here:

http://www.bunkerofdoom.com/mil/m35/vic4/100_2295.jpg

And here below are the NSN numbers, if anyone can find anything out, just so the correct info is presented that would be great! Haney has a few of these right now.

control, intercommunication unit
model m981
p/n 12310226
nsn 5895-01-144-5995

and the amplifier is:
amplifier audio frequency
p/n 12310227
nsn 5895-01-144-5790

- so maybe someone can look these up and remove all doubt. I can't find anything pro or con, so I take my dealer's word on it for now.

Im not trying to cause a $%#@storm, just trying to figure out what you have.

I'm sorry I did not mean to imply that at all, maybe 'argument' was the wrong word, I'm short on the right words sometimes.

Today I found the VIC-4 listed and pictured in Jane's Military Communications 1997-1998. so it does really exist.

Apparently it is a further upgrade from the modified VIC-1 that used the AM-7046 amplifier in the "Interim Fire Support Team (IFIST) vehicle. The VIC-4 is still used in that vehicle, but instead of the three tranceivers the AM-7046 provides for, the VIC-4 takes it up a notch to 4 tranceivers. I guess if you have enough of a fist, you can operate more than 3 radios at once. (ham radio CW joke, and a bad one at that, just in case it needed explaining)

I have only three crew boxes, but I'll see what others (old-style VIC-1 for instance) might possibly be usable (with less functionality perhaps) if I can find anywhere the schematic for the VIC-4. It does not appear to be indexed on the usual web sites, so it may be something either special, rare, or unrepairable except by swapping modules, they did not bother with the manual. The VIC-4 crew box looks alot like the C-10680, but has no such number on it.

VIC-1 with AM-1780 amp and C-2298 crew boxes: 2 tranceivers and 2 receivers.
VIC-1 with AM-7046 amp and C-10680 crew boxes: 3 tranceivers and 1 receiver.
VIC-4 with amplifier NSN 5895-01-144-5790 and crew boxes NSN 5895-01-144-5995: 4 tranceivers.

progress report

Today, 16 hours marathon on the system..

-all connections and crimp-lugs soldered.
-added manual/off/auto switch to switched 12/24V system. can be turned on manually or when truck power is turned on.
-added an indicator lamp to show when system is on so batteries won't run down.
-made final connecttions to wiring on battery equalizer.
-hung headsets on cab wall with genuine military mike hangers. Thanks to Bjorn for the general idea of where to put them.
-ran interconnect cables between two crew boxes in cab. 7FT one worked ok.
-dressed all cabling behind passenger seat.
-dressed wiring under dash.
-added fused 15A 12V "triple cigar lighter" socket under dash.
-installed VIC amplifier including making a brace and also added additional crew box in shelter. (that crew box is important for troubleshooting!)
-modified and installed 100A DC breaker panel (Rockwell rackmount unit) where DC 12/24V enters inside shelter. wire size from batteries to shelter is #6.
-interfaced vehicle 24V system to shelter 24V system.
-system check - RT524 has poor audio on the intercom, sounds fine in its own speaker!?! (radio determined to be at fault)

electrical needs: DC filtering system between vehicle power and intercom; low air buzzer noise, alternater whine, and fuel guage noise appears in headset background. Ok I am picky.

folow on tasks:
clean up mess in shelter, install pyro guage, and probably start fixing the passenger seat.

I was just about to get to that.

power and intercom:
http://www.bunkerofdoom.com/mil/m35/vic4/index.html -has been updated

seats:
http://www.bunkerofdoom.com/mil/m35/seat/index.html

military gooseneck lights I am going to install in cab:
http://www.bunkerofdoom.com/mil/lamp/index.html
(Steve Haney may still have some of these)

pyro guage got put off. Here are some pics as requested, but please visit the pages for the textplanations and more pictures. I mean, who looks at magazines for the pictures?
--More to come..

updated to show the inside of the shelter where the VIC-4 amplifier is now mounted and connected to the radios as well as how the switched power was connected inside along with some circuit breakers.

http://www.bunkerofdoom.com/mil/m35/vic4/index.html

go to page 3 for the latest.

Nice work! Most impressive.

Thanks! - I have to clean that mess up before I go on the trip. Also install those gooseneck lights in the cab, and a CB in the shelter to hook into the intercom. I hope I can get that all done this weekend. I replaced the power cables on the lights, but mounting them seems to be troublesome. 1. they are heavy and 2. the mounting method doesn'tseem to fit anything in the cab. I wonder what they are from anyway. I want them at the back of the cab facing forward for maps and better light on the instruments at night. Speaking of which, the guage lighting in that thing is dismal but I have not tried any tricks with itexcept playing with different brightnesses of lamps. In the mil-veh list I posted some results of trying different lamps a couple years ago, but can't find it now. I will try the below when i can:

In 2004, Bjorn posted to the mil-veh list: "The instument panel has two covered light fixtures that illuminate the gauges for night time viewing. I noticed that the bulbs are not deep enough into the socket to give full brightness through the "windows" of the instruments. The filament of the bulbs is on the wrong side of the dash panel. By replacing the mounting screws for the light assemblies with longer ones and adding a 3/16" spacer between the inside of the dash and the light assy, the filament ends up almost entirely on the inside of the panel for much better illumination. Try it, it worked for me.
Also, keep the dust off the "windows" (the slots behind the front panel) of the gauges".

I know this is resurrecting an ancient SS thread, but a question: are the VIC-1 cables/control boxes interchangeable with the M981 VIC-4 amplifier box? I have a M981 amp box and the connections look the same as VIC-1 components...

maddawg308 said:

I know this is resurrecting an ancient SS thread, but a question: are the VIC-1 cables/control boxes interchangeable with the M981 VIC-4 amplifier box? I have a M981 amp box and the connections look the same as VIC-1 components...

Click to expand...

The cables, headsets, etc. can be used with either system.

The crew boxes and amplifier are absolutely not interchangeable. Do not try it. I can't swear that things will short out and smoke but I can say it will not work.

The VIC-1 has simple switches inside the crew boxes and this can be seen in the TM schematic.

The VIC-4 has a somewhat complicated electronics board with its own powered electronics inside each of the crew boxes. The VIC-4 crew boxes get power from the VIC-4 amplifier. I have never had the internal schematics for the VIC-4 system but I would like one to copy.