Nav/Strobe Light wiring...any noise issues?

[mulde35d]

I was curious and emailed AeroLED about how much amperage runs through their Sync wire. They said it is about 10 ma or 0.01 Amps (if I did the conversion correctly). Definitely not enough to effect a magnetic field.

[JDA_BTR]

My setup is stock. Shielded 18G 3 strand in the fuse for nav, strobe, and sync. Unshielded to the tips connected at the wing root. Strobe ground and light ground connect together and run to the wing root where it attaches to fuse. Shield in fuse length grounded at wing root fuse.

Heated pitot with no controller has twisted 14g in the wing with a ground at the wing root.

No noise in my GMA245 audio from lights or strobe. All AeroLED. Gmu22 in the left wing doesn’t blip at all. Probably will help to look at your audio jacks and make sure they aren’t grounded in any way and that your shields for audio are exactly per plans.

[Mudfly]

Thanks guys for the info and ideas.
Jon, I like the idea of keeping the sync wire separate and using the third conductor in the shielded wire for the ground. The only reason I was going to use the shield as ground is because I believe I remember reading that method "may" reduce the magnetic field better. I may need that capability due to the location of my magnetometer in the left wing. However, I'll need more information as to whether using the shield as a ground return is an accepted practice in the aviation world. Using the shield as "shield only", if I recall correctly, provides better reduction of external noise..radio interference , etc. Based on that info, your plan seems solid since you are mounting the magnetometer in the tail cone.
This seems like one of those areas where there are a few right answers. I just need to make a decision and move forward.

[JDA_BTR]

You should use the third wire for ground. It is twisted with the other two so will mitigate any magnetic flux effect of the varying DC current. If you make the shield the return ground you don't get that benefit.

[Mudfly]

JDA_BTR . You talked me into it. I'm going with the shielded 3 conductor, and will use the 3rd wire as a real ground vs using the shield. Final answer!

[M McGraw]

Good morning,

I updated post #2 to explain where I found my strobe, wig-wag noise in my system. Short answer is it was getting in via a metallic panel mounted PTT.

[JDA_BTR]

I used the standard wing wiring since I didn't know any better 3 years ago. I use the ground wire provided for the landing light to bring the nav/strobe ground back to the fuselage ground point, as showed somewhere in the AeroLED instructions. I didn't use any shielded wire in the wing. Nothing is grounded out in the wing.

G3X system with GTR45, GTR 20, GTN 650 and GMA-245; Zero noise anywhere in any combination of equipment/radios/anything.

I also grounded per the plans with the screw point at the fuselage next to the wing root.

I did make one change and my pitot wiring is ground/12V twisted pair, but still grounded at the wing root.

I think that the biggest item to prevent noise is single-point grounding every audio cable exactly as shown in the docs, and making very sure the mic/phone jacks are not grounded by using the proper fiber/rubber washers made for that.

[JDA_BTR]

I'm curious why you have a panel-mounted PTT? I wish I had a speaker sometimes.....