This installation is for a HO-Scale Bachmann Spectrum K4 4-6-2 Pacific using a TCS WOW121 Steam Decoder, B-MB7 Motherboard with built in Keep Alive® and 28mm WOWSpeaker.
HO-Scale Bachmann Spectrum K4 4-6-2 Pacific shown prior to installation.
To start off this install, we must first remove the front and rear tender shell screws highlighted above. With these screws removed, gently pull upwards at each end and along each side of the frame, lift the shell off of the frame.
The Bachmann Spectrum K4 4-6-2 Pacific tender shown with the shell off. Remove the wires from the original lighting board and remove it from the chassis.
Trim to fit the wires and tin them as needed. Using small lengths of TCS 3/32" and 3/64" shrink tubing, insulate these solder lead if necessary. Be careful to make note of each wire function, to be able to connect them to the new board in the same way.
With the 28mm WOWSound speaker inserted face down into the frame enclosure, using hot melt glue, mount this assembly to the frame as shown. NOTE: You must be very careful to avoid getting glue on the speaker cone. Glue on the speaker will ultimately cause it to produce no sound and fail.
Attach the B-MB7 to the frame and solder the motor, track pickup, speaker leads and front light wire to it according to the included wiring diagram.
Shown with the wiring correctly soldered in place. Note that the rear track pick up and speaker wires have portholes preset into the board to facilitate tangle free routing. You can now plug in your WOW121 decoder. Now you can close up the tender and reinstall the coupler assembly to the locomotive. Be sure to be mindful of wire routing and reassembly of the shell as to not damage or foul the installation. Your Bachmann Spectrum K4 4-6-2 Pacific is now WOWSound equipped and ready to roll!
Note: this is an alternative installation for an earlier version of this same locomotive. In this case, we installed a TCS AK-MB1 motherboard with built in Keep Alive®, WOW121 Steam Decoder and a UNIV-SH4-C WOWSound kit. To accomplish this installation, you must trim off the upper portion of the tender shell support posts as shown above highlighted in red. This will allow space for the motherboard thickness in the installation.
You must also slightly enlarge the AK-MB1 screw holes to fit the tender shell screw spacing as highlighted above in blue. This is a very minimal opening as you will see in 'dry fitting' the board.Take care to trim carefully to the minimum need.
When the shell is reattached after the installation, the original screws will now fit down into the motherboard screws holes, allowing you to reattach the shell to the frame with the posts resting on top of the motherboard. To support the motherboard center, build up a small platform with double sided foam tape.
With the 25mm x 14mm WOWSound speaker inserted into the UNIV-SH4-c enclosure, using the same double sided tape, secure this into the top front of the shell. To provide venting for the sound to properly escape the shell, we drilled several small, inconspicuous holes into the coal load of the tender. They are invisible from the outside and provide a great sound!
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