This installation is for a HO Scale Athearn P42 using a TCS WOW121 Diesel Decoder, RTR-MB1 Motherboard with built in Keep Alive®, 28mm WOWSpeaker and UNIV-SH2-C.
HO-Scale Athearn P42 shown prior to installation.
To start off this install, we must first remove the front coupler screw highlighted above and it's housing. With the coupler removed, while gently pulling outwards at each end and along each side of the frame, lift the rear of the shell off of the frame and then the front. Take care to release the handrails and ladders as you lift off the shell so they don't break.
The Athearn P42 shown with the shell off. Remove the wires from the original lighting board and unclip it from the chassis.
Trim, tin or lengthen the wire leads as needed and using small lengths of TCS 3/32" and 3/64" shrink tubing, insulate these solder leads.
The RTR-MB1 has a motor pick up clip pre-attatched to the bottom, so mounting it onto the locomotive could not be easier.
Attach the RTR-MB1 to the frame and solder the motor and track pickup wires according to the included wiring diagram. The RTR-MB1 boards have on board 1.5volt power supplies to conveniently power all the original 1.5volt bulbs that come with your Athearn locomotive. The front headlight and rear light pads are configured for 1.5volt use. Additional 1.5volt pads are available for other connections for ditch lights etc. If you prefer to use LED lighting as an option, there are LED solder connection pads. Current limit resistors are built into the board so no external resistor are needed for LED use. 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.
With the 28mm WOWSound speaker inserted into the UNI-SH2-C enclosure, using foam double sided tape, mount this assembly to the shell as shown. 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. On this installation, we routed the lighting wires in tape around the speaker enclosure to keep the wires neat.
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 www.digikey.com. We use part number 802534B BK032-ND
Close up the locomotive and reinstall the coupler assembly. Be sure to be mindful of wire routing and reassembly of the shell as to not damage or foul the installation. Your Athearn P42 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