This installation is for a HO-Scale SD-24 using a TCS WOW121-Diesel Decoder, AK-MB1 Motherboard with built in Keep Alive®
and UNIV-SH4-C WOWSpeaker kit.
HO-Scale train SD-24 prior to installation.
To start off this install, we must first remove the front and rear coupler screws highlighted above in red 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 SD-24 shown with the shell off. Unplug and remove the wires from the original lighting board and remove it from the chassis.
With the original lighting board removed, trim, tin or lengthen the wires as necessary.
Remove the screw highlighted in red above on the front weight and remove the weight, saving it and the screw for later reinstallation.
The front of the frame shown with the front weight removed.
Attach the AK-MB1 to the frame and solder the motor and track pickup wires according to the included wiring diagram.
Reinstall the front weight to check the clearance and that the AK-MB1 is not touching the motor flywheel.
Using a small dab of hot melt glue, mount the front (left) and rear (right) LED's on top of the screw mounts facing up into the light tubes.
We have found that LED light output is brightest when shinning directly into the end of the light tube, but in some circumstances, they may be placed along the length of the tube as well with satisfactory results. In doing so, white light LED output would be least affected, while non-white LED output will be more affected by placement.
TCS motherboards include onboard current limit resistors for LED use. There is no need to apply external resistors for LED use.
Solder these wire leads to the AK-MB1 according to the included wiring diagram and permanently install the front weight.
Insert the 25mm x 14mm speaker into the UNIV-SH4-C enclosure and using double-sided foam tape, mount the assembly onto the frame right in
front of the rear weight as shown above. Wire these leads to the AK-MB1 according to the included wiring diagram. For this installation, as the fan assemblies are open and there are loose fan blades inside, to prevent vibration from these blades we find it desired to place a small drop of appropriate plastic model glue at the junction of the fan blade to the spindle, to prevent them from moving and distorting the sound.
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.
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-24 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
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