Hover Tim
Sorry - I havn't quite understood the problem.
Your servo tester should produce exactly the same signal as your receiver does, so any problems should be the same (unless you have a computer Tx, in which case ANYTHING can be happening (literally) depending on what you have told the Tx it is)
What is the motor, what is the speed controller? My forward-only brushless ESC uses the Whole throttle stick for forward speed control, and so the whole turn of the servo tester dial. Depending on the motor and load on it they will do all sorts of starting, stopping, stuttering and sometimes sitting singing or buzzing, especially if used unloaded. (My ESC is a cheap non-adjustable one and I don't expect too much from it)
Tell us more, please - have you got an airscrew on it?
BobF - interesting, but difficult
Could you just sketch how and where the schottky diode goes on a brushless motor with 3 terminals all being fed with synthetic AC whichever way the motor is turning?
I agree with you in relation to big DC motors, but have NEVER understood how ESCs survive when used as forward/reverse but die when used forward only?
andrew