Matronics Email Lists Forum Index Matronics Email Lists
BBS Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Degaussing

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List
View previous topic :: View next topic  
Author Message
tshort



Joined: 21 Oct 2017
Posts: 10

PostPosted: Wed Apr 25, 2018 12:44 am    Post subject: Degaussing Reply with quote

The aft mounted magnetometer in my RV 10 has failed interference testing, only when the rudder moves.

Garmin tells me I need to degauss the rudder cables.

Anyone have suggestions on how to do so?


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
View user's profile Send private message
rv10pro(at)gmail.com
Guest





PostPosted: Wed Apr 25, 2018 1:22 am    Post subject: Degaussing Reply with quote

Start with a simple  (Free)Android phone app
Such as Gauss Meter by Keuwlsoft.  It will help locate or confirm the item that becomes mangetized.

A degauss process is a coil of wire which creates a demagnetize field when switched on.  They were commonly used by TV techs in the 60s -70s to remove interference in Cathode Ray color picture tubes back in the day.

John Cox

On Wed, Apr 25, 2018, 01:50 tshort <tmshort(at)gmail.com (tmshort(at)gmail.com)> wrote:

Quote:
--> AeroElectric-List message posted by: "tshort" <tmshort(at)gmail.com (tmshort(at)gmail.com)>

The aft mounted magnetometer in my RV 10 has failed interference testing, only when the rudder moves.

Garmin tells me I need to degauss the rudder cables.

Anyone have suggestions on how to do so?




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=479541#479541






===========
-
Electric-List" rel="noreferrer noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
===========
FORUMS -
eferrer noreferrer" target="_blank">http://forums.matronics.com
===========
WIKI -
errer noreferrer" target="_blank">http://wiki.matronics.com
===========
b Site -
          -Matt Dralle, List Admin.
rel="noreferrer noreferrer" target="_blank">http://www.matronics.com/contribution
===========





- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
user9253



Joined: 28 Mar 2008
Posts: 1291
Location: Riley TWP Michigan

PostPosted: Wed Apr 25, 2018 4:52 am    Post subject: Re: Degaussing Reply with quote

Try a soldering gun (NOT a soldering iron). Remove the two screws that hold the heating element. Put the heating element around the rudder cable and reassemble the soldering gun. Turn on the soldering gun and slowly move it along the rudder cable, being careful not to burn yourself or anything else.
I have never done this and have never heard about others doing it. But hey, it is worth a try.


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

_________________
Joe Gores
Back to top
View user's profile Send private message
BARRY CHECK 6



Joined: 15 Mar 2011
Posts: 720

PostPosted: Wed Apr 25, 2018 5:35 am    Post subject: Degaussing Reply with quote

Hello Shorty:
Very Interesting!
In the good old days it was very easy to make a Degaussing Coil (D-C), actually the coil was already made for you and all you had to do was hook up 110 VAC.
The Coil was the DEFLECTION COIL on the back of the old TV's...  It is the large coil that slipped over the shank of the CRT... Cathode Ray Tube.   
All that a D-C is, is a very long length of a coil of wire.  To the ends of the coil you apply 110 VAC through a PUSH BUTTON switch.  It continuously reverses the magnetic fields at the rate of 60 times per second (60 Hz).  The coil is then slowly moved in ONE DIRECTION along the length of the item you wish to demagnetize.
OK, lets prove the cables are magnetized.  I doubt it!  Why?  Because the cable are made of a low ferrous metal.  The cables are advertised as Stainless Steel (S/S).  True, not all S/S is non-magnetic.
Start with a COMPASS - Move the compass along the length of the cables and of course the STEEL pivot points.  The Compass will point directly to the magnetized item. 
Sounds like you are installing a G5 system?

ALSO...  Go back and watch your DG/HSI as you move the rudder peddles.  The Heading should change as the peddles are moved.  Move them slowly from stop to stop.  My SWAG is:  If the Heading does NOT change - Don't worry about it, you are good to go!  The test procedure is way more sensitive/selective than the Magnetometer and the DG/HSI.
If the DG/HSI does move then YES - Use the D-C.
Side Note:  You can also do as ships do:  Fly a course in direct Opposition to the magnetic fields of the earth.  This is used to Degauss the ship...  in your case the plane (ship).  Look up Ship Degaussing procedures - Check out "The Chapman's  Manual".
Since there are very few old TV's which you can steal a coil from let's move to your next options.
1 - Look for a place where you can purchase or rent a D-C.  Look at the old electronic shops.
2 - Obtain a ROLL of INSULATED wire - 24 to 34 AWG about 1,000 Ft.  You will have to have access to BOTH ends of the wire.  Then all you have to do connect a 110 VAC line and a Push Button Switch to the ends.  The go GAUSS!
Best of luck,
Barry


On Wed, Apr 25, 2018 at 4:44 AM, tshort <tmshort(at)gmail.com (tmshort(at)gmail.com)> wrote:
Quote:
--> AeroElectric-List message posted by: "tshort" <tmshort(at)gmail.com (tmshort(at)gmail.com)>

The aft mounted magnetometer in my RV 10 has failed interference testing, only when the rudder moves.

Garmin tells me I need to degauss the rudder cables.

Anyone have suggestions on how to do so?




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=479541#479541






====================================
-
Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
====================================
FORUMS -
eferrer" target="_blank">http://forums.matronics.com
====================================
WIKI -
errer" target="_blank">http://wiki.matronics.com
====================================
b Site -
          -Matt Dralle, List Admin.
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
====================================





- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
View user's profile Send private message Send e-mail
BARRY CHECK 6



Joined: 15 Mar 2011
Posts: 720

PostPosted: Wed Apr 25, 2018 5:36 am    Post subject: Degaussing Reply with quote

WOW!  GREAT TRICK JOE!!!  GREAT TRICK!
Barry
On Wed, Apr 25, 2018 at 8:52 AM, user9253 <fransew(at)gmail.com (fransew(at)gmail.com)> wrote:
Quote:
--> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com (fransew(at)gmail.com)>

Try a soldering gun (NOT a soldering iron).  Remove the two screws that hold the heating element.  Put the heating element around the rudder cable and reassemble the soldering gun.  Turn on the soldering gun and slowly move it along the rudder cable, being careful not to burn yourself or anything else.
I have never done this and have never heard about others doing it.  But hey, it is worth a try.

--------
Joe Gores




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=479544#479544






====================================
-
Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
====================================
FORUMS -
eferrer" target="_blank">http://forums.matronics.com
====================================
WIKI -
errer" target="_blank">http://wiki.matronics.com
====================================
b Site -
          -Matt Dralle, List Admin.
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
====================================





- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
View user's profile Send private message Send e-mail
nuckolls.bob(at)aeroelect
Guest





PostPosted: Wed Apr 25, 2018 11:37 am    Post subject: Degaussing Reply with quote

Try a soldering gun (NOT a soldering iron).
Remove the two screws that hold the heating
element. Put the heating element around the
rudder cable and reassemble the soldering gun.
Turn on the soldering gun and slowly move it
along the rudder cable, being careful not to
burn yourself or anything else.

I have never done this and have never heard
about others doing it. But hey, it is worth a try.


It works. I've used the soldering gun to
demag small tools. There are several articles
on the 'net for doing similar tasks.



Here the author made up a coil of longer
wire (gives stronger field with less heating).

One could take a piece of bare 12AWG copper
and form it 4-5 turns around the target
material before reconnecting to the soldering
gun. I've measured the current in stock
Weller tips at over 200 amps. So using
the single-turn of a stock tip would
give you 200+ ampere-turns of flux.

Fabricated coils will be higher
resistance but if you can get 150A
through 5 turns, your degaussing flux
rises to 750AT.


Bob . . .


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
skywagon



Joined: 11 Feb 2006
Posts: 184

PostPosted: Wed Apr 25, 2018 11:51 am    Post subject: Degaussing Reply with quote

. . . any chance there is other electronics "back" there that are operational, such as tail strobe and power supply causing interference with flux..??


[quote] ---


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
View user's profile Send private message
nuckolls.bob(at)aeroelect
Guest





PostPosted: Wed Apr 25, 2018 6:51 pm    Post subject: Degaussing Reply with quote

At 02:49 PM 4/25/2018, you wrote:
Quote:

. . . any chance there is other electronics "back" there that are operational, such as tail strobe and power supply causing interference with flux..??

Excellent question. I am skeptical of the notion
that control cables have become magnetized . . .
and if they were, they would have to carry
flux lines longitudinally . . . i.e. little
to no discernable changes in magnetic field
as the cables operate to affect rudder
position.

But if moving the rudder has an observable
effect, then there has to be a foundation
in physics for the observation.

On the other hand, does it matter? If
the magnetic compass feature is 'swung'
with the rudder centered . . . what
is the probability of introducing a
critical error into the system's magnetic
nav data with a large rudder excursion?
Most autonomous attitude tracking involves
very small excursions of flight controls.
If rudder motion was a source of error, just
how often and under what conditions would
that error manifest?



Bob . . .


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
ronaldcox



Joined: 24 Jan 2008
Posts: 16

PostPosted: Thu Apr 26, 2018 7:52 am    Post subject: Re: Degaussing Reply with quote

nuckolls.bob(at)aeroelect wrote:
Try a soldering gun (NOT a soldering iron).
Remove the two screws that hold the heating
element. Put the heating element around the
rudder cable and reassemble the soldering gun.
Turn on the soldering gun and slowly move it
along the rudder cable, being careful not to
burn yourself or anything else.

I have never done this and have never heard
about others doing it. But hey, it is worth a try.


It works. I've used the soldering gun to
demag small tools. There are several articles
on the 'net for doing similar tasks.



Here the author made up a coil of longer
wire (gives stronger field with less heating).

One could take a piece of bare 12AWG copper
and form it 4-5 turns around the target
material before reconnecting to the soldering
gun. I've measured the current in stock
Weller tips at over 200 amps. So using
the single-turn of a stock tip would
give you 200+ ampere-turns of flux.

Fabricated coils will be higher
resistance but if you can get 150A
through 5 turns, your degaussing flux
rises to 750AT.


Bob . . .


I wonder if an old magnetic tape eraser would work.

I have one that I used to use to erase magnetic tapes, and I'll bet that would work. If you can find one in a second-hand shop, that might work. Might even be easier to find than a soldering gun!
Mine looks like a small clothes iron encased in a plastic box with a handle and a trigger.

Used to use it for VCR tapes, audio tapes, and computer backup tapes when the need arose. I've seen them in the aircraft aisle at the local Salvation Army store. Confused

Also, it wouldn't have to be the cable that's magnetized. As others have said, that's unlikely. But it could be a steel bolt, or possibly bell-crank or swaged-on fitting.

I'm trying to think of other things in that area that would be ferrous metal, but there isn't much in most planes. There's the hinge pin, but that wouldn't change position with rudder movement.

Just another possible solution.

Ron


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

_________________
Ron Cox
Glasair Super II F/T
Under Construction at C77 - Still just about to fly!
Back to top
View user's profile Send private message
tshort



Joined: 21 Oct 2017
Posts: 10

PostPosted: Fri Apr 27, 2018 2:28 am    Post subject: Re: Degaussing Reply with quote

Thanks for all the replies.

I am virtually certain it is the cables:

- the test passes on all other parameters (turning off / on all the equipment in the tailcone, etc etc). The test shows significant error as soon as I move the rudder at all.

- I downloaded an app for the phone (per the suggestion above), and it does detect magnetic fields near the cables.

Since we had already reassembled things and had the bag wall back in, I used the solder iron technique on the cable ends and cable outside of the tailcone. Measurements before and after with the phone app did show less detected.

Finally, I calibrated the magnetometer as per Garmin's instructions. With ground testing and test flying yesterday, I saw zero movement of the indicator with any rudder input.

Since I am flying VFR only, I am going to continue to monitor / test fly, and next time I have occasion to get back in the tailcone I may make some additional efforts at degaussing.


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
View user's profile Send private message
BARRY CHECK 6



Joined: 15 Mar 2011
Posts: 720

PostPosted: Fri Apr 27, 2018 6:31 pm    Post subject: Degaussing Reply with quote

Shorty:
A COMPASS will literary Point at the problem.
And, if the magnesium is very high you should be able to do it from the outside of the plane.  The aluminum will offer very little shielding.
Barry
On Fri, Apr 27, 2018 at 6:28 AM, tshort <tmshort(at)gmail.com (tmshort(at)gmail.com)> wrote:
Quote:
--> AeroElectric-List message posted by: "tshort" <tmshort(at)gmail.com (tmshort(at)gmail.com)>

Thanks for all the replies.

I am virtually certain it is the cables:

- the test passes on all other parameters (turning off / on all the equipment in the tailcone, etc etc).  The test shows significant error as soon as I move the rudder at all.

- I downloaded an app for the phone (per the suggestion above), and it does detect magnetic fields near the cables.

Since we had already reassembled things and had the bag wall back in, I used the solder iron technique on the cable ends and cable outside of the tailcone.  Measurements before and after with the phone app did show less detected.

Finally, I calibrated the magnetometer as per Garmin's instructions.  With ground testing and test flying yesterday, I saw zero movement of the indicator with any rudder input.

Since I am flying VFR only, I am going to continue to monitor / test fly, and next time I have occasion to get back in the tailcone I may make some additional efforts at degaussing.




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=479589#479589






====================================
-
Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
====================================
FORUMS -
eferrer" target="_blank">http://forums.matronics.com
====================================
WIKI -
errer" target="_blank">http://wiki.matronics.com
====================================
b Site -
          -Matt Dralle, List Admin.
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
====================================





- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group