thongbong said:
No one knows for sure what it's for but my guess is that some of the h3-3d gimbals are prone to jello caused by ultra sonic vibrations in the motors due to a dirty power source. If you play guitar, I'm thinking its like the 60hz hum you hear, and the anti interference reinforcement board is like a power conditioner like a Voodoos lab.
Now everyone that says jello is caused by the gopro aperture only, its only half way true. Jello can be caused by vibrations in the frame, props or gimbal motors... I've actually had a controlled experiment where I can make my gimbal motors vibrate at a very high rate, causing the infamous JAY EE EL EL OH!
thongbong, you are partly right: The power filter is designed to filter out the interference to the video out signal from the gimbal for FPV purposes. It is NOT designed to deal with Jello, which is caused by airframe vibrations or wind buffeting the gimbal.
The filter board is connected between the 8-wire connection coming out of the P2 and connecting to the H3-3D. If you are using an FPV hub, the filter board should connect between the gimbal 8-wire cord and the FPV hub. This will only affect the analog video signal to the video TX. It has no effect on the digital Hero3/3+ recording, which remains in-camera.
Hope this helps