Installation for a Athearn SD40 using a WOW121-Diesel Decoder, RTR-MB1 Motherboard with Keep-Alive™
and GEN-SH1 WOWSpeaker Kit by TCS.

This was performed by our friends from DCC Xpress installations.
They offer high quality WOWSound installations for a flat rate complete with free return shipping!
You can find them at:

These items are available in the WDK-ATH-8 which was used for this installation.

RTR-MB1 Motherboard with Keep Alive™ WOW121-Diesel Decoder GEN-SH1 Speaker Kit
Click here for more information on the WDK-ATH-8 and the rest of the WOWDiesel Kits line.

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 Athearn SD-40 with the shell on prior to installation


First, remove the coupler box screws and the coupler boxes from both ends of the locomotive as highlighted in red above.

With the couplers removed, the shell should lift right off the chassis. Shown with the shell off.

Next, remove the wires from the original lighting board and remove it by lifting it from the rear of the engine.

With the original lighting board removed, Attach the RTR-MB1 motherboard onto the motor mount and solder the motor and track leads to it. When attaching
the wires to the pads, it is not necessary to insert the wires through the holes. We recommend attaching the wires flat on top of the solder pads.
Next, remove the rear weight saving the screws from the weight .

With the weight removed, insert the 35mm x 16mm speaker into the GEN-SH1 enclosure and mount this assembly to the chassis using the saved screws.
Solder the speaker leads to the RTR-MB1.

If your speaker enclosure installation covers the portholes on the enclosure, we recommend adding new port hole(s) similar to the original porting. Be sure that the new portholes are the same size and amount of the original and are vented freely into the locomotive We have found introducing a port of the correct size greatly increases the volume and sound quality of the installation. Too much or too little porting decreases the sound quality.

Wire the lights according to the included wiring diagram and solder these to the motherboard. 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, which 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

Finally, you can replace the shell (it should slide over the installation easily), and replace the couplers and your WOWSound equipped locomotive is now 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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