What's the requirement for a separate annunciator backing a 430W? I recall there's some max distance measurement between the 430w and the EFIS (a Dynon D100 in my case) beyond which trips the requirement.
It's not the distance between the 430 and the indicator head, it's how far the 430 is off the centerline of the pilot's instrument scan.
For a WAAS 430, if the unit is 11.8 inches or more from the centerline, you need a VLOC/GPS annunciator. But the Dynon EHSI covers this requirement, so you never need it with a Dynon, assuming the Dynon is in front of you.
If it's more than 13.41 inches, you need all of the annunciators. The Dynon doesn't do them all, so you'd need an annunciator panel.
