Autopilot symptoms --- EDC-10A Magnetometer DB-9

[Alfio]

Just discovered I was using a metal housed DB-9 connector on the EDC-10A magnetometer. While a magnetic survey of the area (rear deck of an RV-9A) revealed no magnetic anomalies, the compass would swing mildly when very close to that connector.

A call to Dynon support confirmed that there is an all plastic connector that is to be used with the magnetometer. I must have accidently substituted another connector when I did the install... almost 5 years ago.

My symptoms were wallowing in roll, or we had to use higher sensitivity settings which induced twitchiness. I settled for the dumbed down settings (roll rate = 0) and that worked for the most part. Also when capturing a track it showed as an underdamped system and was in need of some pilot guidance.

It will be a few weeks until we fly again so I will not be able to confirm that the connector is the issue. Meanwhile though, I thought I would alert those that may see some strange autopilot behaviour with the EDC-10A magnetometer so they can check that they have the correct connector installed.

Alfio

 

[dynonsupport]

Just discovered I was using a metal housed DB-9 connector on the EDC-10A magnetometer. While a magnetic survey of the area (rear deck of an RV-9A) revealed no magnetic anomalies, the compass would swing mildly when very close to that connector.

A call to Dynon support confirmed that there is an all plastic connector that is to be used with the magnetometer. I must have accidently substituted another connector when I did the install... almost 5 years ago.

My symptoms were wallowing in roll, or we had to use higher sensitivity settings which induced twitchiness. I settled for the dumbed down settings (roll rate = 0) and that worked for the most part. Also when capturing a track it showed as an underdamped system and was in need of some pilot guidance.

It will be a few weeks until we fly again so I will not be able to confirm that the connector is the issue. Meanwhile though, I thought I would alert those that may see some strange autopilot behaviour with the EDC-10A magnetometer so they can check that they have the correct connector installed.

Alfio

Slight clarification - the DSUB 9-pin connector SHELL that Dynon Avionics has supplied for several years now is flash-plated plastic. As part of the connector, the thumbscrews are metal, and the two small bolts and nuts are also metal, and there is metal in the connector. But in our experience, those small metal pieces are easily compensated for during a Compass Calibration. But a metal DSUB shell could have enough of a magnetic signature to cause problems to the EDC-D10A.

 

[Alfio]

I was referring to the metal in the connector:
http://t1.gstatic.com/images?q=tbn:...oBhASaJrV_KIwkt24Q0QeUkNMMNsg7daNK8zob-oHWWSQ

I did not install the backshell nor the screws, instead I used tie-wraps to keep the connector attached to the EDC-10A.

In that case, I will try to use a small degausser and try to demagnetize the connector. I thought I was on to something.

Back to the drawing board....
As Emily Litella would say "Never Mind...."

 

[JTD]

Also: Dont use a magnetized screwdriver when working with the metal screws. They can take on some residguel magnetism