I use BEL 2-3 cell lipo charger connected to an old computer ps.
For gyro, keep gain in center at first, take off and note which way it drift then make a tiny adjustment to get sweet spot. Make sure to pull Tx rudder all the way to left when making adjustment (this will reset your tail). You should get locked tail due to better tail ecs (pixie-7p) than mine (ics-50).