Unsual radio spikes

I´am having some trouble with my rc radio calibration. I´am using a Dx6e transmitter and a AR620 receiver. To connect it to the navigator I have used a PWM to SBUS encoder and connected the output to the RC pins on the navigator. When I try to calibrate my radio the bar of each channel moves on its own. I´am using mission planner for my calibration but have encountered the same problem in QGC. My connections seem correct because I have tried connecting this configuration on a Navio flight controler and I don´t get this error. In the navigator I have changed three parameters.

  • RC_PROTOCOLS = SBUS
  • SERIAL1_PROTOCOL = RCIN
  • RC_OPTIONS = 36
    ¿Is there any other parameter I should change? Any kind of help would be appreciated.