Digital Command Control signals aren’t shaped like normal AC waveforms found in house wiring. The rising and falling edges are straight instead of curved. When they’re sent through long track buses they can be distorted, which could lead to damaged decoders.
Some manufacturers suggest placing a snubber, as seen in fig. 4, at the end of each track bus wire pair to help dampen the distortion. This is a simple circuit consisting of a resistor and capacitor in series. NCE recommends, and Digitrax sees the merit of, a 0.1mF capacitor and a 1/2-watt resistor somewhere around 50 to 150 ohms.
Model Train Operations 