Remote Compass location

[David_Johnstone]

I am building an RV9A & am about to fit the remote compass. Before starting I would like to know if there are any problems associated by mounting the Whelan Strobe power pack anywhere near the remote compass.
Thanks

 

[dynonsupport]

Generally we have not had problems with strobe packs. Many people with RV's put the compass behind the baggage compartment near the strobe packs.

That being said, keep it as far away as is practical, avoid the power lines coming in for sure, and always remember that you can usea simple wet compass in whatever location you are considering. Turn the power on and see if it swings. If if doesn't move, you're good for sure.

 

[David_Johnstone]

Thanks for the fast response. I will advise you on the outcome, but it won't be for a few weeks yet.
David

 

[Etienne]

Just keep in mind that if you do put the remote compass where you would normally put a wet compass, don't put the two of them anywhere near eachother

I stuck my remote compass about 30cm's away from my wet compass with blue-tak just to see it working and it wasn't at all happy (obviously)!

 

[raspegren]

I am also in the final assembly of an RV-9A and am pondering whether to go to the wingtip or behind the baggage area with my compass. I have a whelan power unit in the wing as well as behind the baggage area. If the wiring from the 10A to the remote compass done with shielded wire can it bundle with the same wires as the whelan power wires? I have not completed the wiring so cannot test with a wet compass yet. If I hooked up the wires to run the strobe maybe I can then test with the wet compass. If it is steady I assume the location will be O.K., right?

Roger

 

[meljordan]

I have two remote compass modules in my RV-6A as I have a backup EFIS D10A. I had mounted the original EDC in the tail cone, half way back from the baggage bulkhead and the empanage. There is a convienent bulkhead that you can use for the mount. It has always worked perfectly, with a max error of +-1degrees for all cardnial headings.

Anyway, when I installed the second EFIS D100, I decided to mount the EDC in the wingtip. I checked out the various locations, and found that the strobes didn't effect the compass, but the landing light did if mounted forward, and the counterweight pipe used in the ailerons would effect it if mounted aft. So I mounted it right in the middle. Imagine my surprise the first evening I turned on my nav lights and saw the compass move 14 degrees! Seems I had not really understood that you can't have wires with high current in them anywhere close to the EDC. This past week, I moved the EDC back to be next to the first unit in the tail cone, and happily both EFIS compasses match exactly. I found that there was just too much going on in my wing tips and the tail cone had a nice open area with nothing ferris and no wires to interfere. A little more work to install, but a better locaton for me.

Just my experience for you to consider.

Best Regards,
Mel Jordan
Tucson

 

[dynonsupport]

The issue with the EDC is not the bundling of the communication wires with other wires. The issue is that the compass reacts to magnetic fields, and any wire with current creates a magnetic field. The field is porportional to the current in the wire.

Because of this, you can bundle the wires together however works for you, but you need to keep the actual EDC module away from wires that are not low current data wires. If you keep it 6"-12" away from the power wires you should be fine.

 

[marvminiely]

I want to install BOTH the remote compass AND the OAT probe in the tail cone of my RV6a. Can I bundle the leads and run them forward together to the panel? Also, do I need to keep clear of the transponder antenna and cable?

Marv

 

[dynonsupport]

Hi Marv,

If you are using the EFIS OAT (3 wires), it actually uses the compass to process its signal, and so its wires terminate there. If you are using the OAT that connects to the EMS (2 wires), you can indeed bundle the leads together and run them forward to the panel together.

You only need to mount the compass itself away from power, current carrying wires, and ferrous metal. The not the wires that go back to the panel can be next to anything. The connection over these wires is digital, not analog, so they are not susceptible to interference.

 

[13brv3]

If you are using the EFIS OAT (3 wires), it actually uses the compass to process its signal, and so its wires terminate there. If you are using the OAT that connects to the EMS (2 wires), you can indeed bundle the leads together and run them forward to the panel together.

Rats! I guess it pays to never assume I know anything :-[

I had good luck with the EDC under the empennage fairing on my old RV-3, that I decided to put it there on the RV-8 as well. The OAT is mounted on the side of the fuselage, below the right horz stab. This is where I had it on the RV-3 as well, and it worked great.

I've already mounted these items on the RV-8, but haven't wired anything up yet. The OAT wire was really long, and I cut it off, "knowing" that it only had to go to the EDC. Unfortunately, I have a D180 for the RV-8, and now realize that the wires are supposed to go to the D180, NOT the ECD like they did on my previous D10A.

It looks like this is a simple resistive temp sensor. One end is grounded, and the other goes to the D180. Would I be correct in assuming that I can just extend the OAT wire to reach the D180?

Thanks,
Rusty (never assume)

 

[dynonsupport]

Rusty,
The older OAT's could not be extended due to capacitance issues.

Any OAT that has been purchased from us in the last 9 months or so can be extended as far as you need.

If it's 3 wire, it still goes to the EDC, even on a 180. If it's two wire, it goes to the D180 or EMS. Either one will work on a D180, but the hardware is different between the 3 and 2 wire OAT's so they need to go to the right location.

 

[dynonsupport]

Additionally, the OAT that connects through the EDC can still be purchased for $65.

You can indeed extend the wire for the OAT that you already have.

 

[13brv3]

Thanks for the info. I'll just use the OAT that I already have, and extend the wires. This certainly isn't my biggest mistake to date

Rusty

 

[N747PW]

Can I mount two remote compasses next to each other? Is there any possibility of interference with each other?

Pat

 

[dynonsupport]

They'll be fine next to each other.

 

[Thomas_Schaad]

I am planning on a second D10A, being used as EHSI connected to a second EDC. Having 2 EDC's, will I use a second OAT probe as well or can the second set pick up the number trough the DSAB in order to have winds aloft?

Thanks for your reply and kind regards

Thomas  

 

[dynonsupport]

Thomas,
Sharing OAT's (and everything else) is something that we hope to do in the future, but sharing data between two EFIS units is way down on our list, since most customers have an EMS and an EFIS, so we're focusing there first.

Basically, we expect that you'll be able to do it some day via DSAB, but it could be quite a while before that is done.

What we would suggest today is sharing the OAT by wiring it to both EDC's. Hook the OAT up to one EDC normally, then split the yellow wire and run just the yellow wire to the other EDC. This will allow both EFIS units to share the OAT. The only tradeoff here is that if the EFIS powering the OAT dies, the other EFIS will loose OAT as well, but this would occur with DSAB sharing too.