Both Analog servo and Digital servo, use plus width signal. Which is Analog, Not Digital!!


The plus width is 1300(us)ns as the center point. The range is from 1000us-2000us, servo moves from one end to another for Digital Servo.


Even a "written" AM system today uses PPM modulation as its in a FM system, so even most AM system can be use with digital servo. as long as the center plus width is within range. Old AM system use a different plus range, so they may not work because out of range signal.


The Digital Servo, which is called because it uses a digital control board to continuously move the servo motor back and forward to hold a better/stronger center point and have much better initial torque when the servo start movement. it has nothing to do with the FM or AM system.


Digital Servo have much better Holding Power, but it’s very Power Consuming even with no outer servo movement. Digital servo is mostly used when torque and respond which are important.


Some racer like to use a Analog servo, because it’s more smooth while initial steering moment (less wheel hopping on lower traction surface).