Presented by Tim s Trains
This presentation will show you the basic steps required to install a sound decoder and speaker in a steam locomotive. This particular locomotive is a Bachmann 4-8-4 with a Vanderbilt tender. I will show the basic thought process and techniques I generally use doing sound installs. Obviously there are hundreds of types and brands of locomotives and decoders/speakers available. These ideas and techniques can be adapted for similar installs.
This install involves a TCS (Train Control Systems) WOWSound decoder with a KA-2 keep-alive. I generally try to fit the largest speaker and enclosure possible into the available space. This install will use a Tony s Dream Speaker and enclosure 1 in diameter.
FIRST and foremost How does it run? If it jerks and stutters or waddles down the track, DCC will NOT FIX it. Take the loco apart and repair any problems with the mechanics of operation before you start!! This loco runs very smoothly
Next step.. Let s take the loco apart to see what type motor and mechanism, and space we have to work with. This one took about ten minutes to locate all the screws to separate the drive mechanism from the locomotive.
Look over the chassis and verify what parts do what. Light? Motor Connections? Track Pickup? Smoke Unit? What is all this stuff attached to the motor?
Okay. Motor is all cleaned up and ready to go. Next?
What does this do.?
This a board that brings track power, motor leads, headlight, and the smoke unit all together. I left it in place to ID the different wires later.
Alright, we are pretty much down to bare bones. Let s see how the decoder, keep-alive, and speaker will fit in the locomotive. If at all.
The top of the motor at left is very near the top of the boiler cavity. Not looking too good. Let s look in the tender for additional space.
Uh oh. Tender without trucks reveals no screws to open it any further. It is a solid tube and the two weight plates inside are loose and rolling around. There is a tab up front. Hmmm.
A little gentle tugging and prying gets the front of the tender off and we have access to the inside!! Removed the block of styrofoam and both the weight plates. Sound Install Steam
The plates are secured to each other with double stick tape. However they are not secured in the tender. We ll address that later. They will make a great platform for all the decoder and sound equipment. Sound Install Steam
Perfect fit, everything is tied and soldered together and fixed in place with double sided tape. Sound Install Steam However there are no track power pickups or connections to the locomotive.
Now we have to establish the connections between the tender and the locomotive. Train Control Systems has a great tether solution with their JST6/7. We are going to need all seven wires!! Sound Install Steam
Now we are going to have to create a pathway from the tender to the locomotive while maintaining the ability to unplug the connector. The tender is completely closed! Thank goodness for Dremel tools and steady hands. Sound Install Steam
Once the opening and the female end of the connector fit snuggly together it is time to epoxy the connector into the opening and set it aside to harden. This is also a great time for a nap or snack to keep you going Sound Install Steam
When it has hardened completely, place the decoder assembly and the tether next to each other and connect all seven wires, color for color. Twist and solder, then heat shrink for protection. Sound Install Steam
There s the finished tender. There s a nice opening for the sound to get out directed right at the locomotive. A little black paint or permanent marker and it will hardly be noticeable. Sound Install Steam
Ok, I think this is where we left the locomotive half of the install. What s next? Well, we need to find a way to get this end of the tether up and into the loco to pick off all the existing wiring.
Sometimes I just plain get lucky. See the square opening in the bottom of the frame? There is nothing above it and it comes out right behind the motor!!
Some quick work with a drill and I have the perfect path for the tether!
Just like the tender it is now time to connect wires to their counterparts in the loco. Track power is black and red same as the tender connections.
Motor leads are orange and grey, same as the tether connections in the tender. Solder and shrink for protection. ALWAYS test the motor for direction.
Here I have already connected the function wires to the function they will control. White to the - of the LED and yellow to the left side of the smoke unit.
Remember, BLUE is always + 12volts from the decoder. I have both positive function wires soldered to the blue lead. The 12 volt feed for the LED has a resistor in line to take the 12 volts down to about 4 volts.
Solder and heat shrink for protection. The large diameter heat shrink on the left will cover the resistor and all the associated connections. Try to leave a little bit of slack for some wiggle room or corrections.
Finished with all the connections. Now we need to pack it all in without fouling any moving parts and/or gears.
This should eliminate any loose wire issues. Time to test our work!!
Remember how carefully I clipped the tether from the loco to the back of the cab so I would have plenty of wire to plug it in? Yep, it happens. I forgot the chassis fits snuggly about 1.25 from the back of the loco..75 isn t enough to reach the tender connector!!
The slack I had left for just a reason like this wasn t enough. I had to go back and reconnect the headlight and smoke unit for the extra wire necessary.
But, the extra wire allows for a nice relaxed connection between the locomotive and the tender. Too much wire might drag along the track. Not enough might cause restrictions while turning.
I have the loco setup to run on my test track up here. It has not had any adjustments made for operation or sound levels. It s pretty loud in my opinion. Questions and comments are always welcomed..tjl