Ok let me explain a few things.

When you enter programming mode for the 9c you have basic menu and if you press the mode/page button again that gives you the advanced menu. If you have the super, the ACRO function gives you a gyro option. If you have the original 9c you set the gain with the atv's that the single wire is plugged into, usually channel 5.

The easiest way to explain how the gain works (in english) is to visualize it on a rotary knob. Any time the knob is turned to the left of center we are in avcs (heading hold or HH) mode. Any time its turned to the right of center its in normal mode. 1/2 way is the cut off point to change modes. When the knob is fully left you are in HH mode with 100 percent of the available gain, as we turn the knob slowly to the right we are still in HH and the gain value is decreasing until we get to the half way point where its at 0, as we cross 1/2 way we switch to normal mode and start increasing the gain till the knob is at full right when we are in normal mode and 100 percent gain. So with ATV's and a toggle we are simply setting the stop point of the knob either way. From 50 to 100 left is 0 to 100 gain in HH mode, a value of 75 yields half the available gain so 75/75 for the end points would give toggle up 50 percent gain in HH and toggle down would give 50 percent gain in normal. Thats about where you want to start your experements.

As for the rudder and hh mode you have to understand what's happening. The gyro is giving a command to turn (which it got from the stick) at a given rate. On the ground the airplane just sits there and it isn't obeying the command to turn so the gyro patiently waits for it to do so. If you yaw the nose in the direction the plane should be turning you will see it go back to neutral. Also if you move the airplane w/o a rudder command you will notice the rudder stays put till the plane returns to its original heading (desireable in a heli)

In normal or rate mode as we call it the gyro simply gives a correction to stop the rotation and return to neutral to await something else to do, if you were to spin the airplane in the yaw axis it would continue to give correction till it stops.

Now some other things you need to know. Make sure there is no rudder trim or subtrim in the model, mechanically center everything. Dont use the transmitter to change the trim after the gyro is initialized or your're going to have problems because the gyro memorizes center when it boots, any trim is taken as a command to turn. Also make sure you have the transmitter on first and the toggle in avcs mode, the gyro should flash for a few seconds then come on steady, make sure you don't move the rudder stick or the model till the lights on, you will hear the tail servo lock in but like I said, its a 3 second process. Then you can flip to normal mode (light off), any time there is a stick input it will double flash, thats correct too. If it just flashes 1 flash slowly its not gettting an init signal from the channel its hooked up to or the single wire isnt hooked up.

As for end points, set the end points on the rudder channel to 100 and adjust the throw with the limit pot on the gyro while the gyro is initialized correctly and in normal mode (light off). If you want to de sensitize the rudder reduce the atvs and it will reduce how fast the gyro tells the plane to turn, trust me it looks strange but it works.

As for delay since you are presumably using a standard servo, set DS MODE OFF or you'll burn up your servo and the dlay to about 1/4 turn from 0. If your rudder wags coming out of turns turn up the delay a bit at a time, if it wags in flight reduce the atv values to reduce the gain.

Do the following test, give right rudder and note correct movement.

Set AVCS mode on the transmitter and move the nose LEFT, (as viewed from above counter clockwise yaw) and note the rudder correcting to the RIGHT, if thats backwards flip the NOR-REV switch on the gyro.

I pm'd you my number call me if you have any questions.