This installation is for a HO-Scale Kato Atlas RS-1 using a TCS WOW121-Diesel Decoder and AK-MB1. This install was performed by TCS.

Important Soldering Tip:
Please do not use any flux either liquid or paste on the mother board. It will damage it. Use only Rosin core solder approved for electronics use.
We recommend to use only Kester "44" rosin core, SN63PB37, .015" diameter, part number 24-6337-0007.
This can be ordered from Techni-Tool under Techni-Tool part number 488SO157

The WDK-KAT-2 WOWKit was used for this installation:

AK-MB1 Motherboard


WOWSpeaker Kit


HO-Scale Kato RSC-2 prior to WOW121-Diesel Decoder, AS-MB2, and UNIV-SH4-C installation.


To start off this install, we must first remove the front and rear couplers and their housings. Once that is complete, the shell will lift off of the chassis.

Do this by holding the fuel tank with one hand and squeezing the shell on either side front and back while pulling up.

Shown with the shell off.

To remove the original lighting board, remove the plastic clip shown on top as well as the two screws that are holding it down.
With these removed, lift it off of the frame. This board and lights will no longer be used.

With the original rail pick up comming off of a common rail on each side and motor power brought in via the metal clips,
these will need to be modified for the installation.

First, straighten and clip these to shorten the metal leads. Solder a connection point to each and attach new motor lead wires.

Shrink wrap these leads to insulate and protect against shorts. Next, solder a connection pount to each track lead and mount a wire to
each of these. Keeping the solder connection to a low profile with ease reassembly of the shell. Branch each of these leads to allow
connection to the two separate track solder points on the mother board.

Using hot glue or faom, double sidded tape, secure the front portion of the AS-MB2 to the frame, then screw the rear portion down
to hold it firmly in place. Do not overtighten this screw. In red is illustrated the track pick up solder connection. .


To mount these LED's place a small dab of hot glue on the end of the light tube (as shown above in red) and press the LED facing into the light tube into the hot glue. For our
installation we decided to use the TCS 1417 (2x wired surface mount sunny white LED kit) as a replacement for the existing lights.
The front light tube was shortened to allow room for the speaker. This was achieved in a small saw and then heating the end to polish.

With the lighting in place, mount the KA4 into the top of the shell with foam, double sided tape. Be aware of the fit and that it will rest
behind the speaker and in front of the AS-MB2 when assembled.Solder the te two leads to the AS-MB2.

Next, using foam, double sided tape, mount the pre soldered speaker assembly on the front of the frame and solder to the AS-MB2.

At the same time we placed the speaker we took this opportunity to lace our wires to group them and keep the installation neat. With the 2 LED's mounted on the light tubes you can connect the LED's to the AK-MB1 motherboard. The AK-MB1 has built-in resistors for LED's so we don't have to worry about adding external resistors

NOTE: Using lacing cord is a important step to neatly bundle and dress the wires which are prone to being pinched or cut by the shell (during closure) or tangled by the drive train. This simple addition makes a tremendous difference in keeping your installations neat and preventing accidental shorts from damaged wires.
Lacing cord is a wax impregnated string used for wire bundling and making harnesses.
There are many choices of lacing cord available from Digikey We use part number 802534B BK032-ND

Next, clip the speaker wires to length and solder them to the speaker connections on the AK-MB1.

Finally, install the WOW121-Diesel decoder onto the AK-MB1 motherboard.

Replace the shell (taking care not to pinch any of the wires), remount both of the couplers, and your SD40-2 is now WOWSound equipped and ready to run!

Other solder tips: When stripping wire, only strip a tiny little bit of the insulation. Strip no more then a 1/64 of an inch. When the wire gets tinned with solder the insulation will shrink back more. Try to not expose any more wire then 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

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