RC TRANSMITTER: price range a lot.  It’s possible to buy one from U$40.00 to over U$1,000.00 depending on the number of channels and features that it has. Each channel allows one individual action on the aircraft that can be controlled. It’s something like one channel for throttle, one channel for turning right and left, one channel for pitching forward and backward, one for rolling left and right. Four channels are the minimum for a Quad. With more channels it’s possible to have switches to change settings while flying. Some specialists recommend using transmitters that have at least 5 channels. The extra channels are useful for switch among different flying modes (see example diagram above). Other experts say that Quads guided by GPS require at least an 8 channels transmitter. 

MODES: there are two different modes, mode 1 and mode 2. Basically, it’s different configuration for each stick. The Mode 1 configuration has the elevator control on the left joystick and the throttle on the right one. The Mode 2 is the most easy and common for Quads because the stick represents the movement of the aircraft. It has the elevator control on the right joystick and the motor throttle on the left one. The right joystick self-center in the both axis, whereas the left joystick only self-center in left |right axis and clicks in the up | down axis in order to allow the throttle setting