This installation is for a HO Scale Athearn Alco PA 1 using a TCS WOW121 Diesel Decoder, AK-MB1 Motherboard with built in Keep Alive®
and UNIV-SH4-C WOWSpeaker kit.
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:

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

HO-Scale Athearn Alco PA 1 shown prior to installation.
To start off this install, you must first gently pulling outwards along each side of the frame and lift the shell off of the frame.
Take care to clear the front coupler as you lift off the shell so it dosen't break..

The Athearn Alco PA 1 shown with the shell off. Remove the original track pick up bars along with the front light assembly to prep the locomotive for the new motherboard.

Using a blunt tool, carefully push against the four plastic tabs found on the bottom of the tank frame to release the motor from the frame.

Lift the motor from the frame as shown above.


Remove the motor pickup clip from the bottom of the motor, flatten the two bent out tabs and solder a motor pick up to the 'top' of the clip. Be careful when removing this as there is a small spring located underneath that will be released when you do. With the new motor pickup soldered in place, insulate this connection with a piece of Kapton tape to prevent shorts.
Reinstall this clip and the motor into the frame, reversing the removal instructions.

Using a small amount of hot melt glue, mount the front LED to the front top of the shell as shown above.

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 on board current limit resistors for LED use. There is no need to apply external resistors for LED use. 

With the 25mm X 14mm WOWSound speaker inserted into the UNI-SH4-C enclosure, mount this assembly to the frame 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.

Using the same double sided foam tape, secure the KA3 Keep Alive® to the frame as shown above. Solder these wire leads to the motherboard.

Attach the AS-MB2 NC to the shell with the same double sided foam tape and solder the motor and track pickup, LED, KA3 and speaker wires according to the included wiring diagram.
Using small lengths of TCS 3/32" and 3/64" shrink tubing, insulate these solder leads if needed.

You can now plug in your WOW121 decoder. Secure the shell wires with small pieces of Kapton tape.

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

Now you can close up the locomotive. Be sure to be mindful of wire routing and reassembly of the shell as to not damage 
or foul the installation. Your Athearn Alco PA 1 is now WOWSound equipped and ready to roll!

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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