For those of you that have converted your layouts to DCC, and want sound in your engines, you may have discovered that installing sound is not as difficult or mysterious as it may appear. In fact, for diesels, the whole trick is finding room under the shell to locate a sound decoder and a speaker. For high hood diesels, this is usually not that hard, because there is usually a fair amount of free space under the shell. However, I model the Long Island Rail Road (LIRR) around 1964, and RS-3 diesels were a large part of the LIRR diesel roster. These engines pose a bit of a challenge because the shell snugly fits around the motor and flywheels. However, loud, clear diesel sound can be installed in these engines relatively easily.
I started with an Atlas RS-3 diesel. The first step is to remove the railings and shell, exposing the motor and flywheels and the circuit board that sits on top of the motor. Carefully remove the circuit board by clipping the wires that come from the front and rear wheel pickups at the circuit board. Carefully bend out of the way the copper straps from the motor that wrap on top of the circuit board . The circuit board can now be removed by gently pushing forward on one of the two plastic clips that hold the circuit board to the engine and lifting up on the end of the circuit board. Once one end of the board is free, the other end should easily lift off.
Now, carefully cut back the copper strap
coming from the side of the motor, so only a short stub is left with
sufficient area onto which to solder a wire. Solder a short length of
fairly fine wire (#22 or smaller) to the copper stub on the side of the
motor. Similarly, clip off the excess copper strap on the top of the
motor, and solder a short length of wire to the remaining copper stub
(see figure 1). As a precaution, before I install the sound decoder
board, I usually cut a small piece of electrical tape and put it over
the motor and top motor terminal, just to better ensure no shorts if
somehow the circuit board were to come in contact with the motor.Installing the Sound Decoder
Soundtraxx makes a sound decoder for Atlas engines that has the ALCO locomotive sound. It is model DSD-AT100LC820042. Install the sound decoder on the engine by snapping it into place over the two plastic clips that held the original circuit board in place. Make sure you locate the end of the decoder with the speaker terminals on the cab end of the engine (the instruction sheet that comes with the sound decoder will show where on the sound decoder board the speaker terminals are.
Carefully strip off a short piece of insulation from the ends of each of the four pickup wires coming from the front and rear trucks. Using a small soldering gun with a pencil tip, carefully solder the pickup wires coming from the front and rear trucks to the two outer terminals on each end of the sound decoder board. Now, on the side of the sound decoder board, right about in the center, there are two solder terminals. Solder the two wires that go to the motor to these terminals. It doesn’t matter which wire goes to which terminal.
At this point, if you want to check out the decoder portion of the sound card, you can put the engine on your layout, program it like you would any decoder-equipped engine, and make sure it works. The engine should respond like any decoder-equipped engine.
Installing the Directional Lights
The Atlas RS-3’s have front and rear lights that are made from pieces of clear plastic, and act as light pipes” that run from the headlight to the center of the engine. As manufactured, Atlas engines had a single light in the center of the circuit board that, when lit, transmits light to the headlight via the plastic light pipes. Since the Soundtraxx sound decoder provides for directional lighting, I found it best to cut off the headlight section of each light pipe very close to the end (about 1/8’ or less) and then glue the headlight portion into place in the shell. I then glued small 12 volt dc bulbs in front of each headlight (Miniatronics makes a small, 12 volt dc 30 milliamp bulb that works fine for this purpose). Because the older Atlas RS-3’s come with weights that fit into ends of the shell, you may need to trim the weights with a file as necessary to make sure they don’t interfere with the lights.
Installing the Speaker and Hooking up the Sound
I have experimented with several different
speakers, such as Soundtraxx, Miniatronics, and TDS. I have found that
the TDS Mini Oval Speaker and the TDS Mini oval speaker enclosure give,
by far, the best and loudest sound. The speaker and baffle enclosure
are available from Tony’s Train Exchange (800-978-3472;
www.tonystrains.com) and
