with the GY401 gain is from 0-50% of servo output a gain of 100%-0% in normal mode, from 50-100% of servo output the gain is 0%-100% gain in heading hold.

that gives you 50% of servo travel covering 100% of gain in one or the other flight modes (normal or heading hold)

so a gyro sensitivity setting of 90 would be 90% of servo travel, which is equal to 80% gain in HH mode. a sensitivity setting of 10 is equal to 10% of the servo output which is equal to 80% of gain in normal mode.

0 would be 100% gain in normal mode and 100 would be 100% in HH mode. 50 would be 0 in either/or/both modes.

kc

EDIT: need to add All of the above assumes you have Aux 2 ATV set to +100/-100 and they should be, if not set them to that and do NOT adjust them to anything different as long as you use the 'gyro sensitivity' function.