How to do this
Dont worry about the gain being 0%, in normal mode the servo goes to center all the time as soon as you let go of the stick.
Set the bellcrank to be vertical or centered. Adjust the pushrod length from the bellcrank to the tail rotor so that in a hover in normal mode at whatever speed you choose to hover at the tail holds without drifting. Different speeds make for different trims, so you need to pick a speed you want to use and go with that. I usually do this at my slowest speed normal mode.
Then go back on the bench and adjust the left/right limits on the gyro so that you get full throw without binding and you're done.
On the gain part, it should show 37 on the gyro screen. It doesn't matter what the TX number is, the gyro screen number is the number you want to go by.
P.S. You NEED to hover the machine and make the final adjustment. The measuring business is all meant to get you in the ballpark but you can skip all that as the bottom line hover test and adjustment is where you really need to be and nothing else really matters after that. Just get your servo centered, your bellcrank centered on the bench and then adjust the rod length in a hover to get the heli to fly with no drift.
MA 1005 Hanson 280, 4153 flts
Spectra 27 3DMax, 3226 flts
Whiplash V1 Hanson 300, 1485 flts
Whiplash V2 Hanson 300, 248 flts