Where to install a magnetometer ?

[jamesm]

I guess I used a poor choice of words  but section behind  just  behind the hat rack  in the tail cone section is. It ~24" x ~ 24"  inspection panel

[ArtVandelay]

My current one is mounted in the tail midway back on it's own shelf, by 30 point in diagram above, that will be my first choice.

[N6758N]

11 hours ago, jamesm said:

I guess I used a poor choice of words  but section behind  just  behind the hat rack  in the tail cone section is. It ~24" x ~ 24"  inspection panel

Mine is mounted right between point 27 and 30 in the tail on its own shelf I built. 

[HRM]

On 8/24/2017 at 10:21 AM, N6758N said:

Mine is mounted right between point 27 and 30 in the tail on its own shelf I built. 

Photo would be nice 

[N201MKTurbo]

I ran the magnetic interference test three times today and get three vastly different results.

If it passes once are you good to go?

[ArtVandelay]

I ran the magnetic interference test three times today and get three vastly different results.
If it passes once are you good to go?

I would say no, just the opposite. I try to figure out the discrepancy. Get yourself an old fashion handheld compass, use it like a divining rod to figure out what's causing the problem.

[N201MKTurbo]

6 minutes ago, teejayevans said:

I would say no, just the opposite. I try to figure out the discrepancy. Get yourself an old fashion handheld compass, use it like a divining rod to figure out what's causing the problem.

That won't work. The interference I'm seeing is very short duration. The biggest is when I turn on the strobes. It will make a big deviation and then settle down within a few milliseconds. Luckily there is only a small deviation when the strobes fire. Nothing seems to make a static error.

[ArtVandelay]

That won't work. The interference I'm seeing is very short duration. The biggest is when I turn on the strobes. It will make a big deviation and then settle down within a few milliseconds. Luckily there is only a small deviation when the strobes fire. Nothing seems to make a static error.

You have a strobe power supply in the vicinity? Could try shielding It and any wires close by as well.

[N201MKTurbo]

I just calibrated it and took it for a test flight. It appears to work absolutely perfect. 

The power wires for the strobe run through the leading edge of the wing, about 3 feet in front of the magnetometer. I think the current needed to charge the input cap is creating a magnetic field around the power wires. I could isolate the power supply from the airframe and run a separate ground wire back to the wing root. This way the returning ground current would cancel the magnetic field around the power wire. Even better if I ran a twisted pair out there for the power. 

But concidering that it works perfect, I think I will leave it alone.

[N201MKTurbo]

So, yesterday when my avionics guy came over to do the transponder and static cert so I can fly with my new toys. He asked "How long did it take you to install all this stuff?" I said it took me about 70 hours. He said that sounds about right. He said that people are always bitching about how much it costs. Now I know why it takes so long.

The job involved removing all the old avionics, building two new radio racks with new dimmers switches and idiot lights. Cleaning up the airplane wireing behind the panel. Installing IFD550, AXP340, Skytrax100, G5 HSI, KX155, KN64 and EC200.

There is nothing like spending long hours laying upside down under a dark hot Mooney panel trying to focus your 60 year old eyes on small delicate wireing devices in 100 degree heat.

When I would get to the hangar the plane would read an OAT of around 120. If I got both swamp coolers going it would eventually get the hangar down to a cool 100.

[ragedracer1977]

54 minutes ago, N201MKTurbo said:

So, yesterday when my avionics guy came over to do the transponder and static cert so I can fly with my new toys. He asked "How long did it take you to install all this stuff?" I said it took me about 70 hours. He said that sounds about right. He said that people are always bitching about how much it costs. Now I know why it takes so long.

The job involved removing all the old avionics, building two new radio racks with new dimmers switches and idiot lights. Cleaning up the airplane wireing behind the panel. Installing IFD550, AXP340, Skytrax100, G5 HSI, KX155, KN64 and EC200.

There is nothing like spending long hours laying upside down under a dark hot Mooney panel trying to focus your 60 year old eyes on small delicate wireing devices in 100 degree heat.

When I would get to the hangar the plane would read an OAT of around 120. If I got both swamp coolers going it would eventually get the hangar down to a cool 100.

When you do my panel for me, I'll make sure it's in February or something that's a little cooler.  

 

[jamesm]

16 hours ago, N201MKTurbo said:

I ran the magnetic interference test three times today and get three vastly different results.

If it passes once are you good to go?

After first location failed  for  the Garmin G5  GMU 11 magnetometer  I have never seen it fail since. Only thing I did different was I used the the  divided on concur approach for  the magnetic survey . I did full survey but did it in 2 parts. 1st part was flight controls, 2nd part was electrical loads .

I have ran the magnetic  interference test  3 or 4 times or so.   I think the first location  it failed because  I didn't remove all my tools  when I ran the test the first time. So  that is  probably  why it failed the first time.

James '67C

[jamesm]

Not sure  if this picture helps....  I may have remount it autopilot servos  cause the Magentometer  too much grief.

 

 

[Bob R]

Hi Everyone,

I'm looking for clarification, advice, etc. I have a 530W and a G5 primary display. At some point, I want to install an autopilot, possibly the TruTrak if it ever gets released. Regardless, I do not have an HSi at this point but I believe I will have to install at GAD 29B for the eventual AP.  I am confused as to what I will gain from adding the GMU 11 at this point. Can anyone enlighten me?

Thanks, Bob

[EricJ]

3 hours ago, Bob R said:

Hi Everyone,

I'm looking for clarification, advice, etc. I have a 530W and a G5 primary display. At some point, I want to install an autopilot, possibly the TruTrak if it ever gets released. Regardless, I do not have an HSi at this point but I believe I will have to install at GAD 29B for the eventual AP.  I am confused as to what I will gain from adding the GMU 11 at this point. Can anyone enlighten me?

Thanks, Bob

You cannot set the compass rose heading on a G5 HSI like you can a DG, i.e., you can't align it to your compass manually.   The GMU11 does that for you.   So, basically, you can't have a G5 HSI without a GMU11 as that is what aligns the directional heading display.

 

[Stanton R]

21 hours ago, Bob R said:

Hi Everyone,

I'm looking for clarification, advice, etc. I have a 530W and a G5 primary display. At some point, I want to install an autopilot, possibly the TruTrak if it ever gets released. Regardless, I do not have an HSi at this point but I believe I will have to install at GAD 29B for the eventual AP.  I am confused as to what I will gain from adding the GMU 11 at this point. Can anyone enlighten me?

Thanks, Bob

Currently the TruTrak only hooks to your GPS. No connections will be made to the G5. The Gad 29B or GMU 11 will not be required

Edited May 11, 2019 by Stanton R

[kortopates]

Currently the TruTrak only hooks to your GPS. No connections will be made to the G5. The Gad 29B or GMU 11 will not be required

Independent of any AP, he’ll still need a GMU 11 for his G5 providing heading info, i.e. HSI mode.


Sent from my iPhone using Tapatalk

[Bob R]

Hi Everyone,

I probably should have told you my end game. Currently, I have a G5,530W and GI-106B as primary, Secondary is another GI-106B and SL30. Also present is a vacuum attitude indicator and vacuum DG. My intent is to rid myself of the vacuum gyro and backup attitude indicator as well as provide for AP expansion. From what I know, adding a second G5 (in HSI) with the GMU 11 will allow me to disconnect the old attitude indicator and DG. Correct? Then by adding the GAD 29, will afford me the expansion for the TruTrak AP, if ever released. I am thinking my assumptions are correct but am surely wanting to verify.

Thanks!!

[Capt.Joe]

On 7/23/2017 at 7:18 PM, carusoam said:

If you are looking for the one you have...

It is hiding behind the access panel that has brass looking rivets(?) not sure why my rivets on that panel are brass looking.

Best regards,

-a-

Brass is non ferrous won’t cause deviation

 

[carusoam]

10 hours ago, Capt.Joe said:

Brass is non ferrous won’t cause deviation

 

Thanks Joe.

indeed brass won’t cause mag deviations…

my quirky response comes from the fact I didn’t know if the rivets could actually be brass…. Or some other fancier alloy… that only appeared to be brass…

PP thoughts only, not a mechanic…

best regards,

-a-

[FoxMike]

I just installed the magnetometer about 2' behind the oxygen bottle (right side of the tailcone).  Not easy to install but seemed to have little interference in that area.  Wiring not done yet so it will be next week before we can text and calibrate it.

[skykrawler]

3 hours ago, carusoam said:

Thanks Joe.

indeed brass won’t cause mag deviations…

my quirky response comes from the fact I didn’t know if the rivets could actually be brass…. Or some other fancier alloy… that only appeared to be brass…

PP thoughts only, not a mechanic…

best regards,

-a-

Maybe they used brake pad rivets