Also often abbreviated as Tx, this is what really has their commands and sends your receiver the commands of the servos and motors.
There are many transmitters (transmitter) available on the market today, and the cheapest start around $30. However, controls away from RC plane or helicopter, with programmable functions, memory model, and simulation software can start around $150 and go to almost $3,000.
All remote RC have some frequency operating on. Older, analog controls operate at frequencies lower, which were determined by a crystal. Modern, digital, remote controls usually operate in the GHz, often to 2.4 GHz range.
RC planes and helicopters remote controls have control levers, which are mostly self-explanatory. In general, one of the two levers of control in a remote control plane is the throttle control lever, and does not have a spring in the vertical direction, which means that it will not bounce back when you released. Remote controls are generally available with this stick from the left or right, and sold as mode 1 or mode 2. remote control RC cars have a trigger and a knob to control different things.
RC remote controls most have something next to the control sticks called molding. This basically slightly alters the position of the levers of control, and is useful to finely alter the position of the servos, or the starting point of a motor controller. Transmitters (transmitter) also often have reverse, reversing the output signal of the control sticks this is normally controlled by a series of switches on the bottom of the transmitter.
The number of channels in a remote sample has the amount of things you can control. For example, a three-channel remote control could handle three things, such as three servos, three engines, or a combination of any of them. Motors and servo drivers receive the same type of signal.
Expo, telemetry, travel Limited and memory model is all things better, transmitters more expensive, but are not necessary for the average project. Expo means exponentially, so that linear movement of their control sticks will lead to a curve of exponential output signal. Telemetry transmitted information of the vehicle (such as voltage of battery, the altitude, the temperature of the engine, etc.) back to the transmitter and displays them in the transmitter. Means Travel Limited that by moving levers of control to its maximum only sends a signal of 30%, or whatever it sets in. These two features are beneficial to sensitive mechanisms and aircraft, so that one can keep better control over them. Memory model simply allows you to store your crop settings in the transmitter, so that you can remember for later use, or eliminate the need for having to readjust all the time if you have multiple devices. Remote control RC cars are often equipped with dual rates, expo, memory, and even the telemetry.
The majority of the transmitters (transmitter) have to join your receiver to ensure appropriate communications. The way to do it depends on your transmitter / receiver.
Many transmitters need 12v to operate, usually supplied by batteries 8AA. This is 8 batteries too for me, so I got a small, 0.8Ah battery and hooked up to my remote control, so I only have one battery that worry, instead of 8 small.