I had one of the 300D at my former employer. At Raytheon's option, the other three wires could be configured for various options. On our unit, RED-BLK was VDC, GRN-WHT was Video and the other three had bias voltages on them but would do nothing, nor change with the scene viewed.. At that time, Raytheon did not wish to disclose further details about the other leads..
The camera would power up and function just fine without further input on the "mystery" wires.
We were lucky to get one, at the time, those were state of the art in low cost cameras. Ours was the better part of 4,000$ with lens..
One rule, do not view large, excessively bright objects if you have stock high gain lens with no iris. One of the grad students attempted to view the uniformity of a warming up, hot 550'C oven from less then a meter away. 4 pixels were permanently white before I found the situation. A silicon wafer makes a decent attenuator.
Make sure the spiral chopper disk inside spins freely.
Expect about a 15-30 second time period for video to appear.
If it helps, our sales rep referred to ours as the "Tank Commander's Thermal Viewer".
Steve