This installation is for a HO Scale Bachmann 2-8-4 Berkshire using a TCS WOW121 Steam Decoder, B-MB4 Motherboard with built in Keep Alive®
and 28mm WOWSpeaker. Shown prior to installation.
To start off this install, all the work is to be done in the tender. We must first remove the front tender screws highlighted above in red.
Next, remove the two rear screws. With these removed, gently pulling outwards at each end and along each side of the frame and lift the shell off of the frame. Take care with the handrails as you lift off the shell so they don't break.
The Bachmann 2-8-4 Berkshire shown with the shell off. Remove the two screws on top of the lighting board and remove it from the chassis, keeping all but the tender track pickup wires attached to the board. Release the rear LED from the socket on the inside of the tender.
Next, remove the two screws found on the top of the plastic platform. Then remove the two screws that are holding the weights in place. Set all these components and screws aside for re-installation.
With these components out, remove the speaker and disconnect it from the original lighting board. This will be replaced with the new 28mm WOWSound speaker. Set the original lighting board aside intact
Insert the 28mm WOWSound speaker into the frame opening face down and secure it with the two original metal tabs in place.
With the speaker securely mounted, replace the weights and plastic platform back onto the chassis with the saved screws. Trim the right rear tab as shown to create a 'flat' surface for the B-MB4 motherboard.
Using one of the original screws, mount the B-MB4 to the chassis platform on the front right of the board. Although not necessary, on this installation, we added a small dab of hot melt glue to the rear posts underneath the motherboard to secure it down. With the motherboard in place, solder the speaker wire leads to it. 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.
With the original lighting board as a reference, transfer the wire leads to the new motherboard. We kept this board in place to be able to remove and place the wire one at a time, to be sure the connections are correct and ease installation.
The B-MB4 shown with all the wire leads soldered in place. Insert the rear LED back into the original socket.
You can now plug in your WOW121 steam 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
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 Bachmann 2-8-4 Berkshire 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