Originally Posted by Roto Rob
Yes, to use a simple device like the servo tester, it would need a gyro that does not need a gain signal, like a Futaba GY240.
Most likely that will work somewhat
.... but it will not stabilize, only slow down roll tendency. And probably not enough.
As far as I know, there are no heading hold gyro's without a "remote gain imput", and with a rate gyro, you cannot stabilize an indifferent object, let alone an inherent instable one.... For that you definitely need an PI(D) controller that will keep correcting until the deviation is completely compensated.