If this is a repeated question, please let me know. I'm a hobbyist electronics person, and ran across symbols on a diagram I didn't recognize. I've attached the image below:

Wiring diagram

What I'm trying to figure out is what the different rings around the wires mean. For example, Earphone Pilot has a connection that shows a ring around one of the wires, and then that hits a T connection where all of them have rings around the wires, too. I've been trying to look it up, but I'm having a really hard time finding info. The full diagram is part of the wiring diagram for a Becker Avionics AR620X transceiver, and the diagram is on page 77 of the PDF here.

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    I'm pretty sure it's shielded wire. – Felthry Oct 17 at 15:35
  • Gotcha, so it doesn't have anything to do with actual wiring, just type of wire? I'm just trying to understand what I do with one wire connecting to the ring that circles another wire – johwiltb Oct 17 at 15:50
  • That wire is connected to the shield around the other wire, then. – Felthry Oct 17 at 15:53
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    @isdi: That's an answer, not a comment! Post it with pride. – TimWescott Oct 17 at 16:01
  • Done! Didn't realize I hit the comment button, links don't work in those btw, hence the silly look at the end. – isdi Oct 17 at 16:37
up vote 12 down vote accepted

That's shielded wire. The ring around it is the outer shield around the cable linking the two parts together. The shield also provides the low side of the signal, so it needs to be connected to the ICs as well; it's the other half of the complete circuit. That T connection you mention is just showing that the shields for all the wires are connected together.

  • Awesome, thank you so much for the help! – johwiltb Oct 17 at 16:00
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    No problem. This does seem like something that would be hard to search for without knowing the answer. – Felthry Oct 17 at 16:01

Felthry is correct. Normally this would be either small gauge coax cable or shielded hookup wire. Note that the shields are connected to various terminals, jacks, etc. The shield is not just 'floating' and surrounding the central wire. The note regarding isolation is to prevent noise from getting into the system from the airframe. An example is:


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