[TX7A]

I'm wiring in a source select switch for GPS to A/P. Do the signal wires from GPS (lets say a 496) need to be shielded?

Thanks

 

[rleffler]

I'm wiring in a source select switch for GPS to A/P. Do the signal wires from GPS (lets say a 496) need to be shielded?

Thanks

All RS-232 and RS-422 lines should be shielded. Be sure only to ground the shield at one end and don't use the shield for a signal line.

 

[Walt]

I agree they "should" be, but with such short runs usually found behind the typical RV panel, I really don't think its necessary. I have seen and run many single wire RS232 lines in RV's, never had a problem.

 

[rv9aviator]

Mine isn't but it is only about 10 inches long. Could that cause any kind of noise in the audio?

 

[Wayne Gillispie]

None of mine are shielded. I will let you know how it works out soon.

 

[rleffler]

Mine isn't but it is only about 10 inches long. Could that cause any kind of noise in the audio?

Probably not, unless your audio lines are unshielded. RS-232 isn't used for audio. What would have a greater potential to add noise is ground loops. I would refer you to Bob Nuckolls book for more information. He may also have a white paper on his web site.

bob

 

[TX7A]

One more thing...

Thanks, Bob & Walt.
I'm seeing three wires that need to be switched (does not include the shield): ARINC A, ARINC B & RS232
Does that sound right?

 

[rleffler]

Thanks, Bob & Walt.
I'm seeing three wires that need to be switched (does not include the shield): ARINC A, ARINC B & RS232
Does that sound right?

Hard to guess without a schematic, but looks to be correct. Also look at your audio lines.