I started by drawing up my plan on my computer. I wanted to have the ability to test all DCC functions for proper operation in my locomotives before installing a decoder. That is a necessity for converting and the wiring of all locomotives. I also wanted the ability to check my decoders for proper operation as well as programming them.
I posted a PDF of my CAD drawing above on my Google Drive, click here to view or download it.
I bought the box above for the tester, it measures 4" X 3½" X 2" high.
I cut two holes in one end for a standard banana plug, that will be the power input to the tester.
Next I cut two holes for NMRA 8 pin connectors, I super glued two connectors in the holes. The Micro Connectors are male on one side and female on the other side. The glued in connectors will serve as sort of header connectors or extensions. Identical connectors with wires soldered to them will plug directly onto the glued connectors making the test module removable from the box.
I used a .03" piece of sheet styrene to make a "breadboard" for building and testing the tester for proper operation.
I use my long nose pliers as a heat sink for soldering. The mini toggle switches, LEDs and diodes are very vulnerable to high heat so a heat sink is necessary to prevent damage.
The picture below is a front view of the parts location on the breadboard.
The Picture above is a rear view of the breadboard showing the wiring.
Another item needed for this project is extension cables. I made a 24" and a 6" extension for the 8 pin NMRA DCC connector as well as for the DCC speakers using 2 pin Micro Mini JST connectors as shown in the picture below. That adds more flexibility to the testing process.
At this point everything works as planed, next will be drilling the holes in the top cover of the box.
At this point my plan is to use the styrene breadboard as a drill pattern and possibly paint it black. White Decals will show up very good under the clear top cover and be protected from heavy usage.
In the picture above my tester is operating a Rivarossi Cab Forward, everything works very good and the only thing left to do is make and install the labeling.