On 12/14/2012 11:04 AM, wrote:
Hello all EEs.

What is standard operating procedure for when and where to use shielded wire in cockpit wiring?

What is standard operating procedure for when and where to use ferrite sleeves?

Do both the positive and negative lead need to pass through the ferrite sleeve?

Thanks for the education.

The simple answer: whenever the equipment installation manual tells you
to use it.

Typically use shielded wire for antenna cables (ie, coax) and microphone
cables.

Newer equipment usually comes with sleeves on the cables they supply.

If the equipment installations done properly, nothing additional is
needed in an unpowered glider. Powered gliders can have interference
generated by the engine running, but again, if the engine electrics are
installed properly and in good condition, there usually isn't a problem.

Generally, I'm amazed at what people can get away with doing!

Most electrical noise problems come from specific problems in the
installation, and can be tough to track down. Ferrites can be an easy
fix sometimes; shielded wiring isn't so easy to install, and it's often
hard for even an experienced EE or technician to know exactly which
cable(s) is the problem and should be replaced.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)