RE: DX7 Mixing question
I recently made the mix you describe on my JR 7202 which is quite similar to the DX-7. The mix is a thro to elev mix. Under rates, I have the upper number 0 and the lower number -4%. I have the sw setting on as I want it on at all times. The offset is 0.
The effect is to adjust the pitch attitude trim down slightly for power off.
Note: While I was playing with the numbers, the mix was left on the mix switch so it could be turned off to prevent being locked into something unwanted. Once happy with the number, it was changed from 'mix sw' to 'On' least one forget to turn it on and expect it to be on during landing.
btw... rmh is very correct, you certainly don't want any 30% number. My plane suffered what I'd describe as a moderate trim need at low power and I started with -3% and added one percent more for the magic feel. A slight trim need would be between 1-2 percent and I'm guessing a strong need would be in the range of 5-7 remembering of course that the number should be a negative number if trimming for down.