This installation is for a HO Scale Proto 2000 GP20.
With milling of the frame, they have been able to utilize a
AS-MB2 NC motherboard, WOW121 diesel decoder, KA4 Keep Alive® and UNIV-SH4C WOWSound kit.
HO-Scale Proto 2000 GP20 shown prior to installation.
To start off this install, we must first remove the front and rear coupler screws highlighted above and their housings.
With the couplers removed, remove the screws located right behind the coupler location.
Next remove the single screw located on the bottom of the tank.
Finally, remove the two screws shown in red above located under the tank.
With these screws 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 Proto 2000 GP20 shown with the shell off. Remove the wires from the original lighting board and remove it from the chassis.
Show above with the motherboard removed. To allow a space for the motherboard and speaker, the frame must be milled as highlighted above to keep
all the components below the original top of the frame.
To remove the top frame from the chassis, locate and remove the two brass screws highlighted above in red and lift the top from the locomotive.
The frame shown post milling. Reattach this to the lower frame in the reverse order of the removal.
Attach the AS-MB2 NC to the frame using double sided foam tape and solder the motor and track pickup 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.
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.
We routed the rear LED lighting leads under the speaker enclosure to eliminate loose wires as shown below before installing the speaker.
The rear LED shown hot glued in place.
Using a small amount of hot melt glue, secure the front LED in the original bulb's location. Solder these leads to the the motherboard according to the included wiring diagram.
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.
Using the same double sided foam tape, secure the KA4 Keep Alive® to the frame as shown above. In this installation, we also used a small dab of hot melt glue to secure it.
Solder these wire leads to the motherboard.
You can now plug in your WOW121 decoder. We secured the wires with a length of Kapton tape.
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 shell screws coupler assemblies. Be sure to be mindful of wire routing and reassembly of the shell as to not damage
or foul the installation. Your Proto 2000 GP20 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. 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
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