if your gyro does not offer HH or you have a HH gyro but have it in norm mode then revo mixing is very useful. on non computer helicopter radios they have pots to adjust the revo mixing, one is called up (works from mid stick to full stick) the other is called down (works from mid stick to low stick). computer radios call it 'revolution mixing' and you can scroll through your radio menu and find it if you don't have an instruction manual. on computer radios people who are not familiar with how revo mixing works will often put in a + value on both up and down, this is incorrect, you want a + for one and a - for the other or your will be adding right (or left) tail input in both directions of stick deflections.always visually check the tail pitch slider for correct deflection in both directions prior to flying.

Up revo mixing adds right t/r as the stick is advanced from mid stick (hover) to full stick as you progress into forward flight or vertical ascent, this prevents the engine/blade torque induced yaw you get as you advance throttle collective.

Down revo mixing adds left t/r as you move the stick from mid stick (hover) to low stick as your descending. this is most often a much lesser value of mixing.

kc