This installation of TCS WOW121 Decoder is for HO Scale Athearn SD70M using a TCS WOW121 decoder, GEN-MB1 with Keep Alive® and UNIV-SH1-C WOWSpeaker kit by TCS.
The Athearn SD70M with its shell on prior to Installation.
To begin this installation, unscrew the front and rear coupler box screws as highlighted above in red and remove the front and rear couplers.
Shown With the shell removed. remove the original wire connectors and lighting board and remove it from the chassis.
The Athearn SD70M with the original lighting board removed. Trim, tin or lengthen the wires as necessary.
Attach the GEN-MB1 motherboard to the chassis and solder the track and motor wire leads in place.
Next, according to the included wiring diagram, solder the front and rear light wire leads to the GEN-MB1 motherboard. In this installation, we used Kapton tape
to secure the wires and prevent shorts during installation and operation.
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.
With the 35 x 16mm speaker inserted into the UNIV-SH1-C enclosure, mount this assembly using hot melt glue into the top of the shell as shown.
Solder the speaker wires to the motherboard and plug in the WOW121 decoder.
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.
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.
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 Athearn SD70M locomotive is 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
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