Couldnt explain to you all the electrical mumbo jumbo but I have had 2 castle systems with spektrum recievers need the caps(one was bought new 3 weeks ago),anytime u touched the steering wheel it would glitch(not enough power to the reciever when steering servo is working)...... its assinine that this day in age this would be required but its true, I have seen others need it also. Piss poor engineering imho.............