Servo jitters on the bench

Setting up a new pixracer from mRobotics with ArduPlane 3.8.1 and have a servo connected to the aileron port 1.

After it boots up, I place the system into manual flight mode. The servo jitters. Also, it does not respond smoothly to aileron inputs from the transmitter; it seems to jump around a bit.

In RTL mode it operates little more smoothly in response to me changing the attitude of the flight controller, but still has some jitters.

I cannot find any parameters to set the PWM rate for servos, except for what seems to be a hard-coded parameter set at 50.

Is there something else I am missing? Thanks,


Do you have a telemetry radio module close to that servo or it’s wires?

It is likely Graham - the whole setup was in a clump on the bench. I moved things around, and then tried a different servo and the condition is no longer present.