Small Scale Cards 3

In many instances, installing the soundcard in a locomotive is not feasible. There may be insufficient space in the locomotive. Or perhaps you have so many locomotives that it is just too costly to install a soundcard in every one.

A better option may be to install the soundcard in a sound trailer which can then be easily run behind whatever locomotive you choose at the time. Box cars, container cars, express cars, baggage cars or any similar rolling stock, which would commonly be seen behind the locomotive, would all be suitable. The picture below shows an installation in a Hornby full brake coach and the method can be used on both DC and DCC layouts.

Before fixing the major components to the coach floor, it is necessary to organize an electrical pickup from the track for the soundcard. In this case, Phosphor bronze strips were purchased from the local hobby shop and were glued in place inside the truck side frames so that they were in contact with the inside of all eight wheels. This ensures a continuous contact with the track when the train is passing over turnouts, etc.

Wires were then soldered to the phosphor bronze wipers and were threaded up through the truck pivots. These wires should be very thin and flexible so that they do not restrict the movement of the truck and cause derailments.

The soundcard, speaker and a 3.6 volt NiMiH battery were attached to the coach floor using double sided tape and the track inputs from the trucks were connected to the M1 and M2 terminals of the soundcard. You may want to paint the battery and other components matt black before installation so that they are not visible through the windows.

The battery has a Panasonic connector and has been plugged directly into the soundcard. This avoids the need to solder the leads from a live battery and risk a short circuit during soldering.

The method of connecting and using the sound trailer on a DCC layout is shown here.