The Berg Microstamp 4-channel receiver is supposed to autodetect the shift of your transmitter and select it automatically. It is compatible with Airtronics/JR or Futaba/Tower/Hitec transmitters.

If the receiver isn't working as expected, you might want to make sure that your transmitter is set for PPM/FM instead of PCM. The Berg receiver will only work in PPM/FM mode. You'll also need a flight pack battery or your ESC and LiPo cell connected to the receiver to power it during testing.

When used with a four servo airframe, most pilots will simply use a Y-connector for the two aileron servos so a 4-channel receiver will be fine.