Shawn, the 3 pin connector port is for a remote 'satellite' receiver (SPM9645-discontinued - replaced with SPM9745). The 4 pin connector port is for an XBUS remote module like the Vario (altitude,) or Airspeed Module. There may be other XBUS modules like a GPS but from what I've seen they've all been discontinued and/or unavailable from Horizon Hobbies. Hope this helps a bit.
All ar636 receivers have 3 solder pads on PCB where a satellite port would be mounted on some of them. It's possible to solder 3 wires directly to the PCB to run an external satellite with all ar636 receivers. It's a job for people who are confident in their elections skills but well worth it.
Thanks for sharing. I have Dxe-AR636A combo from my old 230S RTF Kit and i wanna use my both TX & RX for Deltawing Plane and as far as i know i need ELEVON B setup for the RX. Which firmware and/or model setting that i should use for this. TIA Subscribed by the way :D
Solved. Added two mixes. Mix 1 : Pitch to Roll (Master Rates -100%) Mix 2 : Roll to Pitch (Master Rates +100%) Switch ON for both mixes Finally reversed channel 2 on TX Hope this can help you too