Read The Disclaimer

Vehicle and 5590 Power for the MTX
(SF Vehicle/Personnel Tracker)

The MTX is the small GPS-driven "box" that updates the unit's location to higher command. Current Special Forces operations dictate that every vehicle (and sometimes every dismounted team) be outfitted with an operating MTX.

Problems arise because the only power option available with the MTX's as delivered is power by four CR-123 batteries. If set to update location every 5 minutes, the four CR-123s, at a cost of about $8-12, last about 6 hours. This means that for every vehicle on a 5 day mission, approximately 40 batteries are required at a cost of ~$100 and requiring 10 battery change overs.

This solution is a cable that powers the MTX from one of the cigarette lighter ports. In addition, when tied to a 5590 to Cig Port adapter cable, soldiers can easily dismount with the MTX and power it from a 5590 instead of carrying multitudes of CR-123 batteries. This solution pays for itself within two missions, keeps vehicles on the net more consistantly, and reduces soldier tasks.

Tools

Supplies

Directions

1. - 4. Make/Wire a 5590 to Cig Socket Adapter

Steps 1-4 for wiring the 5590 connector can be found here. You can also purchase one, part number 500102, here.

5. Wire The LEMO Connector

LEMO provides an online assembly manual for this part. The instructions for this connector are on Page 4 of the Adobe Acrobat manual that is found here.

5.1 Cut And Strip Coax Cable

Note: One could simplify the cable construction by using the thin coax for the entire 6.5 foot long cable. We have chosen to splice the thin coax to thicker cable to increase the durability.

Cut a 6 inch length of the thin coax cable and strip it appropriately for the Lemo connector as detailed in their online manual (or paper manual if you received it).

5.2 Attach Connnector to Coax

Insert and solder the coax to the Lemo connector as detailed in their online manual (or paper manual if you received it). Shrink tube is not required at the connector end as a strain relief.

6. Attach Coax To Regular Cable

Cut a 6 foot long section of the regular two conductor cable and attach one end to the free end of the coax cable. Note: It is recommended that you use electrical tape and do NOT use heat shrink to isolate the wires: the heat from the heat gun tends to melt the internal coax shielding and may cause a short.

7. Attach Cigarette Plug

Strip the remaining end of the two conductor cable and attach to the cigarette plug. The MTX cable should be wired "center tip positive." Thus, the center of the cigarette plug should be connected to the center pin of the MTX connector.

Reassemble the cigarette plug, but use the 4A fuse. A 4A fuse is the proper rated fuse for the MTX. However, if you do not have access to a 4A fuse, a 5A fuse should be sufficient and not pose significant risk to the equipment. Using the continuity check (bell function), verify that the cable is wired center tip to center tip, outside to outside between the two connectors.

8. Attach 5590 to Cig Socket Adapter

Using electrical tape, attach the 5590 to Cig Socket Adapter to the MTX cable with electrical tape. This will ensure that if a team has to dismount and take the MTX, the equipment will be ready to be powered directly from an x90 battery.