Sound Decoders with Motor and Function Control

These are the Function buttons for sound control:

SDN144K0A installation question about the capacitorIs the 100microF capacitor needed? Or is it only for use in the Kato E8B unit when both LEDs are removed? If it is part of the installation, what size hole doesit need for mounting? The 100uF capacitor is required for all installations.  The capacitor provides keep alive voltage to the decoder.  This is important when the locomotive runs over a section of dirty track or is traveling through a non powered (insul-frog) turnout.  On non-sound equipped locomotives, typically you will not see the locomotive hesitate or lose power when it encounters dirty track.  With ...