This post documents pinouts of two 2.4 GHz modules, used in RC transmitters.

First one is Xtreme Link XPS-J1 / Graupner XM-J1 iFS module.

You can see pinout of XPS-J1 / XM-J1 at following picture:

As it is possible to know, connection needs only 3 wires to full function of this module:

1. Ground (-) pole = GND of supply voltage
2. +12V, which is switched by main power switch (Battery plus pole)
3. Signal wire, which is positive (to supply voltage) in idle phase

Second one is ASSAN X8F TX module.

Pinout of ASSAN X8F module is at the following picture:

The principle of pins is the same as mentioned above.