Atlas EMD SD26

Scale:
HO Scale


This installation uses the following decoder:


This installation is for a HO-Scale Atlas SD-26 using a TCS WOW121-Diesel Decoder, AS-MB2 Motherboard, KA4 Keep Alive® and 30mm WOWSpeaker kit with lighting connector plugs by TCS.

HO Scale Atlas SD-26 shown prior to installation.
To start off this install, we must first remove the front and rear coupler screws highlighted above and their housings. With the couplers removed, while gently pulling outwards at each end and along each side of the frame, lift the shell off of the frame. Take care to release the handrails as you lift off the shell so they don't break.
The Atlas SD-26 shown with the shell off.
Unplug and unsolder the wires from the original lighting board then remove the four screws highlighted above in red and remove it from the chassis.
Shown with the lighting board removed. In this installation the front track leads are longer than needed, so we shortened them, insulating the splice with TCS part #1320 Black 3/64" heat shrink tubing.
It is important to remove the unneeded orange caps highlighted above in red that are located on top of the motor. Failure to remove them could result in erratic speed control. Also, remove the screw and frame member to the right highlighted in blue. Discard these pieces.
On the rear lighting board, remove the screw highlighted above in red and lift out this board. Save this screw for later.
Unsolder all the wires connected to the rear board shown above left and then solder the included 2 pin connector on as shown to the right. Remount this board back onto the frame using the original screw.
Likewise, unsolder and remove the two front lighting board wires and solder the included 2 pin connector onto it as shown above.
Attach the AS-MB2 to the motherboard mounting clip and using holt melt glue, mount the clip to the frame as shown above, onto the top of the front frame and on top of the motor. Plug in the track, motor, and lighting lead wires to the AS-MB-2 according to your included wiring diagram.
Next, remove the screws holding the speakers on each side as highlighted above in red and remove and discard the speakers.
Using hot melt glue, mount the KA4 to the chassis as shown above and solder the wire leads to the AS-MB2 according to the included wiring diagram.
For this photograph, the train is facing backwards to show the opposite side. Mount the TCS 30mm speaker into the frame opening and secure it with the original retaining clip. Solder the speaker leads to the AS-MB2 motherboard according to the included wiring diagram. As the shell is a very tight fit, it is very important to mount the speaker on to this side only to be able to reinstall the shell properly.
It is important to use this plug as it greatly increases the volume and sound quality. On the opposite side, insert the 30mm speaker plug and secure it with the original retaining clip.
You can now plug in your WOW121 decoder. Lastly, in order to keep the wires neat and prevent possible shorts, lace the wires into a bundle using lacing cord. Now you can close up the locomotive and reinstall the coupler assemblies. Be sure to be mindful of wire routing and reassembly of the shell as to not damage or foul the installation. Your Atlas SD-26 is now WOWSound equipped and ready to roll!

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

Lacing Cord

In order to keep the wires neat and prevent possible shorts, we recommend lacing the wires into a bundle using lacing cord. Lacing cord is a wax impregnated string used for wire bundling and making harnesses. There are many choices of lacing cord available from Digikey www.digikey.com. 
We use part number 802534B BK032-ND