Headphone/mic jack mounting

Hi guys,

A couple of quick questions. I bought the harness for my comm pre-made from ACS.

1) When mounting these, do you drill a hole for the size of the threads, or a larger hole for the boss at the base of the threads?

2) The photo shows how all the various washers were mounted on the jack. When installing, does it go nut/metal washer/fiber washer/panel/shoulder washer/jack? And does the shoulder portion fit up inside of the hole, or point toward the jack?

If it makes any difference, the harness is wired with PTT ground leads.

I was Googling this like mad, trying to find a simple drawing, but couldn't find a thing.

Thanks!

Drill the hole to fit the raised portion on the black washer. The shoulder fits inside the panel hole.

When correctly done, the shell of the jack is electrically insulated from the panel.

rightrudder said:

When installing, does it go nut/metal washer/fiber washer/panel/shoulder washer/jack? And does the shoulder portion fit up inside of the hole,

Click to expand...

Yes.

rightrudder said:

or point toward the jack?

Click to expand...

No.

Exactly as mike said. No part of metal on the jack should be grounded to the airframe, hence the shoulder washer and fiber washer.

Thanks, guys. That all makes perfect sense. Now here's a wrinkle: the Mic jacks have what looks to be an index or anti-rotation tab, oriented so the collared washer won't sit flat at the base of the threads. ????? Should I grind it off or bend it flat?

grind it off.

or slipping a standard 3/8 (or 7/16) washer on it will work also.

Thanks a ton, guys. I appreciate the quick and knowledgeable responses.

Yeah I bought those same jacks from Aircraft Spruce. I used my diagonal cutters and a couple of quick hits with the file and no more anti-rotation tabs.

Insulating Washers

If you drill the mounting hole to the standard 0.50 inches and then find that the raised portion of the washer is too small for the 0.50" opening, B&C Specialty Products sell insulating washers for 50 cents a set that will fit the standard hole size. Their part number S892. The ACS washers were 7/16" for the raised part of the washer and too small for the 0.50 hole.