ILS CDI needle shake and poor autopilot tracking

[HXG]

Recently, I have noticed the CDI needle to shake and dance on an ils approach with up to 1 dot deflection getting worse as the runway nears. This is a new problem in my rv8 with dual skyviews and garmin gtn 650. The autopilot has also had difficulty tracking the ils course. I believe these problems are related. Antenna? I cleaned antennas but problem persists.
The GPS approaches are perfect in autopilot mode with no hsi cdi needle dancing. Any thoughts?
Thanks

 

[dynonsupport]

Fundamentally, this is a radio issue, which you'll need to chat with a Garmin tech/dealer about. SkyView essentially gets a digital representation of the needle position, which it then plops onto the screen. Ie, SkyView can't do anything to influence the behavior of the needle.

 

[dynonsupport]

GPS approaches use fundamentally different technology to navigate (satellites vs ground stations), and are a lot less susceptible to antenna issues in the same way ILS/VOR receiving systems are.