Jonathan, I am not an electronic engineer either but I read elsewhere on this forum that those caps do not power the motor in case of a momentary loss of power. So adding a larger one wouldn't help. To have capacitors as back up power the decoder must have a port or terminal for the caps to hook up to. You can't put the caps across the input power because it would filter out the DCC. When the square wave drops to 0 volts the cap would discharge their voltage which is exactly what the user wouldn't want. I'm not sure what it would do to the DCS signal but my guess is it would degrade it.
The newest ESU Loksound Decoders have a port or terminal for capacitors called Power Packs that will power the locomotive through dirty track. Unfortunately, it looks like they may be expensive as their smaller HO unit is lists for $57. The larger unit (the Maxi) has 5 times the capacitance. I think we discussed this on another thread. Anyway, it would have been nice if MTH had designed this option into their system but, (and I am just guessing here) that they would have had to change a lot on their boards to accommodate it and they probably felt that most of their customers don't want that option so it wasn't worth it to them financially. I'm not knocking them in any way. I am very appreciative that MTH has offered the upgrade kits. I just finished my first upgrade in 11 years and it was almost like getting a new locomotive. It has the same whistle as the locomotive in your video. She runs great and since she has the old fashioned tether she should run great for a very long time.
