This installation documentation is for the HO-Scale Stewart U25B. This installation uses the TCS WOW121-Diesel Decoder, AK-MB1 with Keep Alive and UNIV-SH1-C WOWSpeaker Kit and was performed by our friends at DXI.
The Stewart U25B shown prior to installation. To start the installation, remove the couplers and gently squeeze the sides of the shell toward the bottom and lift up, leaving the platform in place.
Shown with the shell off. Unplug the wire leads and remove the lighting board from the frame.
With the lighting board removed, trim or lengthen, then tin the wire leads as necessary.
To prepare the locomotive for the installation, clip off this small plastic tab.
In this installation, we reused the original LEDs. We cut them off of the lighting board as shown and soldered new wire leads to them, insulating these connections with TCS Shrink Tubing.
Using foam double-sided tape, mount the AK-MB1 motherboard to the locomotive as shown and solder the track and motor connections to it.
Place the newly wired LEDs into their original holders and solder the LED lighting leads to the AK-MB1 as directed in the included wiring diagram.
A closer view showing the motherboard.
With the 35mm x 16mm WOWSound speaker inserted into the UNIV-SH1-C speaker housing, use double-sided tape to mount it onto the frame as shown. If your speaker enclosure installation covers the portholes on the enclosure, we recommend adding new porthole(s) similar to the original porting. Be sure that the new porthole(s) are the same size as 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. Solder these wire leads to the motherboard.
You can now plug in you WOW121 diesel 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 Stewart U25B 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 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