Kato RDC

Scale:
N Scale


This installation uses the following decoder:

MC4



Kato N-Scale RDC with a TCS MC4 decoder which allows for separate forward, reverse, and interior light control - performed by J.M.

First remove the shell by lifting it gently and rocking it back and forth.
Next remove the three lighting elements as shown in the image below. All three lift out easily, though the LED's have small tabs on the sides that may need to be spread to allow the module to pop out.
To use the LED's on DCC we will need to attach two Magnet wires to the underside of the LED modules we removed and lace them through two holes in the LED board. Below is an image of the two LED modules. The lower right red oval on each board is where the green magnet wire should be soldered. The lower left red circle is where the red magnet wire should be soldered. Once the wires are attached run each wire through one of the holes (highlighted in blue) so that both wires come out the top side of the board.
Below you can see the wires soldered in place and laced through the holes. After that use kapton tape to cover the silver strips as shown in the image below. This step is crucial and the decoder will burn up if the kapton tape does not completely cover the silver strips. You should also be careful not to let too much tape hang off the side of the boards because it will make it difficult to remount the lighting module.
Next remove the fuel tank so you can access the bottom of the locomotive as shown below.
Using tweezers or a hobby knife pry the two plastic tabs (highlighted in red in the center below) inward to release the locomotives long plastic board. There are a second pair of these plastic tabs highlighted on the far left of the image below and they must also be released before the long plastic board can be removed.
Once the board is remove it should look like the image below.
Tin the motor tabs as shown below. Be careful not to get too much heat into the tabs as it can melt the plastic motor housing.
Trim and tin the orange and gray wire and solder them to the motor tabs as shown below. Make sure that your heat shrink tubing is on the wire before soldering it to the tab and that it is far enough away from your iron to avoid shrinking early.
Below is what your motor tabs and wires should look like after the heat shrink tubing has been pushed down to cover the whole tab and shrunk to a snug fit.
Remount the plastic board to the locomotive starting with the rear. There are copper bars on the plastic board and on the frame of the locomotive. Make sure that the copper bars on the frame are placed on top of the bars hanging from the plastic board. The image below shows the bars in their correct position. Once the copper bars are lined up press the rear end of the board till the plastic tabs click into place.
The front side is a far bigger challenge because there are three copper bars. Below they are labeled as A, B and C. A and C are both on the plastic board and B is the frame bar. B must be slipped between A and C and then the board can be carefully re-mounted on the front end by pressing it down until the plastic tabs click into place. It is crucial that you have the copper bars in the right order and lined up properly to prevent a short which will destroy the decoder.
Once that is complete you can lace the orange and gray through the hole in the center of the plastic board and press the center of the plastic board until it clicks into place. The two LED modules can now both be remounted into the frame with their wires pointing in towards where the decoder will rest.
Connect the two green magnet wires together with a small bead of solder.
Attach the blue wire from the decoders harness to this bead and another blue wire to connect to the interior light.
Take the interior lighting module and unwind the wires highlighted below.
Once unwound they will look like the image below.
Clip them back, tin them and solder one side to the blue wire you prepared for it and the other side to the green wire on the MC4. Now attach the white wire to the red magnet wire from the front LED module and the yellow wire to the red magnet wire from the rear lighting module. Tin the left and right copper bars and solder the red and black wires as shown below. Make sure that all of the connections are heat shrunk or kapton taped and that the connections all match the two images below.
One all of the wires are attached us a small amount of kapton tape to keep the wires and decoder in place.
Replace the shell and you are ready to run your locomotive.

Important Soldering Tip

Please do not use any flux either liquid or paste on the mother board. Over time, the acidic properties of liquid or paste flux will begin eating away at the fiberglass PCB and will damage it. Use only Rosin-core solder or no-clean flux approved for electronics use.

TCS recommends the use of Kester "44" Sn63 Pb37, .015" diameter Rosin-core solder. Kester part number 24-6337-0007.

You can order this solder from the following retailers:
Digikey - PN:KE1110-ND
Techni-Tool - PN:488SO6775

Other solder tips

When stripping wire, only strip a tiny little bit of the insulation. Strip no more than a 1/32 of an inch. When the wire gets tinned with solder, the insulation will shrink back more. Try to not expose any more wire than half the length of the solder pad at most. In no case should solder or exposed wire wire ever be outside the boundary of the the solder pad you are attaching a wire to.
Click here for important information on properly Stripping and Tinning wire