KFC-225: If it uses the same servos as the KFC200 &
KFC150, etc, it is not a PWM system.

In the KFC 200: They have a bridge of power transistors in the
servo along with a couple of low level buffers. The input to them is a
linear signal on two lines: + right and + left. Only one at
a time is energized. The op-amps that
runs it are in the main box. The summation of the tachometer output
that is located in the servo actually happens in the main box.

Donno... ARE they different? Like KS-270A, etc? (The A model
servos have IC buffers instead of the discrete ones used in the
earlier servos). I have a hunch they did use the same servos...
they would have saved a ton of certification costs by doing that.

BTW: What happens to these is the brushes wear and the motor
back end gets packed with carbon. Makes them start in a jerky
manner. If enough carbon gets packed in, the bearings can fail.

Way to observe: The FD bars move, but the control wheel does
not. They are regular Globe motors, so the brushes for the same
size can be found.

Bill Hale