Wagging VOR Needle

[birddog486]

Wondering if anyone else has experienced this. I've got dual Skyview HDX's and an IFD440. I've been doing CFII training recently and found the VOR needle wagging back and forth. I haven't used VOR navigation in the plane until recently but I assume it's had this behavior since initial install.

When Navigating on an ILS the needle is steady and doesn't have this behavior.

So far I've tried, removing the diplexer and hooking the antenna direct with no change. Tried another antenna with no change. Tested the installed Archer antenna with an antenna analyzer and it appears to be a high quality install with an SWR under 1.5

When tuned to a Localizer the needle is steady and receives at about 18 miles. When tuned to the VOR the Morse code comes in loud and clear at more than 40 miles but the needle wags continuous from 1 mile until you cant receive the signal anymore.

Today I landed at an airport with a VOR checkpoint and the wagging needle was really active. I've been in contact with Avidyne and there looking into whats happening but I'm wondering if this could be caused by anything in the Skyview system.

I've taken two poor quality video's to show what's happening. Flying with some turbulence at about 25 miles here

and on the ground at a VOR checkpoint here

 

[Carl_Froehlich]

There is nothing here to suggest any root problem other than your VOR receiver.

Carl

 

[VIFlyer]

I have been training for my IFR and have the IFD 440 also. When doing VOR approaches, my needle jumps a bit also, but at an airport with a VOT it was rock steady, maybe check your antenna. I had a problem and it turned out the balun (spelling) was broken on one side, touching but not connected which gave me poor reception.

Eric