| The type of modulation that is often referred to as FM modualtion in the RC airplane world is actually pulse position modulation. When PPM is used a series of square pulses are sent out. The distant between the pulses corresponds to the control on each of the different control channels. For example if a 4 channel transmitter were being used 5 pulses would be sent out followed by a sync pause. This series of The distance between the first and second pulses then corresponds to the control on channel one. |
