Athearn CF7 Decoder Installation featuring the RTR-MB1 Motherboard with Keep Alive®, WOW121-Diesel Decoder, and UNIV-SH1-O Speaker Kit by TCS.
First, remove the coupler box screws and the coupler boxes from both ends of the locomotive.
With the couplers removed the shell should lift right off the chassis.
Remove the wires from the board tabs on the original lighting board.
Then lift the lighting board up from the back of the engine to remove it.
Next, clip the RTR-MB1 onto the motor just as the original lighting board had been.
Solder the two violet wires to your 35mm x 16mm WOWSpeaker, glue the speaker into the UNIV-SH1-O (we used hot glue, but CA would work as well) speaker housing and mount it under the fan housing at the rear of the engine.
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.
Next, solder the various wires in the locomotive to your RTR-MB1 motherboard in accordance with the wiring diagram in your motherboard manual.
Though there are thru holes on the the tabs on the mother board for track power and motor power we do not recommend that you thread the wire though them. Please use the preferred method which is to tin the tab using rosin core solder only, tin the wire, then solder the wire to the tab by aligning it laying it straight down. Make sure the wire is short so that it does not go beyond the boundary of the solder pad. Please carefully note how neat and cleanly the wires are soldered to the tabs in this photo. There is no exposed wire off the edge of the the solder tabs. Never use flux for this solder work. Use only rosin core solder approved for electronics.
All the original 1.5volt bulbs supplied with the Athearn loco were used. The white wire solder pad is the forward 1.5v solder pad for the front lights. The yellow wire solder pad is the reverse 1.5v solder pad for the reverse lights. The solder pad marked "1.5V" is the common power source for the bulbs. This motherboard can be configured for LED operation as well, the mother board has built in current limit resistors for LED use. Consult the wiring diagram for LED use.
Now, install the WOW121-Decoder to complete the wiring of your installation.
Finally, you can replace the shell (it should slide over the installation easily, but be careful to avoid pinching one of the wires) and replace the couplers on the engine.
Your WOWSound equipped engine is now ready to run!
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