Initial setup and tuning questions

Hello,

If this is not the place for this post can it please be moved somewhere as I think I’m going to have allot more posts like it as I try to understand this flight controller.

From ardupilot documentation here:
plane.ardupilot.com/wiki/roll-pi … er-tuning/

in “Tuning Overview” it says that I must…
:black_medium_small_square:You have done your radio calibration”

What is this? I have seen a radio calibration screen but I didn’t see any calibration, only a display of my transmitter movements.

in “Initial Assessment” it says to…
"1.Take-off in manual and adjust the trims and throttle to a cruise position so that the plane flies straight and level at a speed that you are comfortable with. This will normally be somewhere between 30 and 60% throttle depending on how overpowered your model is.
2.With the plane flying away from you switch to FBW-A. It should continue to fly wings level and at a fairly constant height (it may climb or descend slowly). If it wants to roll or pitch more than a small amount then there is a problem with the models trim, autopilot level or radio calibration and you need to solve that first before proceeding further.
"
Step #2, if using my usual flight controller, I would expect my plane to roll/pitch depending on how much trim I had applied during step #1. I would need to land and save my trim settings. Does APM somehow know what is trim and what is me on the sticks?

Also, on this page…
plane.ardupilot.com/wiki/ardupla … OWER_INPUT
It shows the telemetry radio specifically powered by the bec and not from APM telemetry port.

In my HK APM 2.7 I used the supplied splitter cable which powers both radio and minimosd from APM telemetry port. Is this likely to be a problem?