On the old Tsunami TSU-1000 sound decoder, there is a large cylindrical Capacitor (or at least, that's what I think it is) attached by 2 wires to the decoder with a plug. What does it do in the scheme of things.
Not something you can easily do away with then, as I suspected, if you want things to work smoothly. In my case it's going to use up valuable speaker space. Have to come up with a custom Cell phone setup..Correct, except the Keep-Alive is not only for the sound, but also to keep the locomotive moving if it encounters a brief interruption in power (dirty rails, insulated turnout frog, etc.). Generally, most of the capacitors will supply power for about 10 seconds, which should be long enough to get the loco over the bad spot. Soundtraxx Tsunami has a small plug that will connect to the main decoder (TSU-1100, TSU-2200-2, etc.). IIRC, TCU's WOWSound keep-alives have to have the wires soldered to other wires coming from the decoder.