How to Connect Turnigy receiver or Flysky R9b receiver to Pixhawk (Ppm encoder)?

Hi guys!

I am trying to connect one of my radios to Pixhawk but none of them have the ppm output. Does anyone recommend any receiver with a ppm output that works with one of these radios or a ppm encoder I can use?

Thank you in advance!

I have purchased 5 (or so) of these PPM encoders and all have worked as desired: