EMI interference or what?

[saghirmann]

Has any one experienced waves in the background during engine operations with change in pattern with change in RPM? What are possible causes and remedies?

 

[dynonsupport]

Not exactly sure I'm understanding what you're seeing. Can you elaborate?

 

[saghirmann]

So to elaborate, When the engine is operating at high RPM, say above 2000 for a Lycoming 540, one can notice dim waves travelling across the display especially PFD. May be during daytime it is not very prominent but it is definitely at night time quite prominent.

 

[dynonsupport]

We've noticed cases of panel vibration interacting with the way the display backlight , which can create the illusion of interference. This is similar to the effect of a TV screen recorded with a video camera - you see lines because the frames that the camera captures aren't exactly timed with the frames that are being recorded. Vibration can create this same effect. Try touching the display itself (lightly) when you see this, or pressing on the bezel or the panel around the display firmly. Does that change the character of the "waves"?