Headphone Jack Insulation

Taildrgr · #1 11-08-2013, 07:21 AM

Most people reading this post will think this is very obvious to them, but I hope posting this will help someone like myself learn something they did not know.

I am working on my panel installation and recently purchased my headphone and mic jacks.

I had read on the forums about the need to insulate the jacks when mounting using fiber washers.

The jacks I purchased had fiber washers sandwiched in the layers of metal between the pins, and I thought that was what was being talked about. Also, the jacks came with the nuts and metal washers to mount them so I thought that they were ready to mount.

Lo and behold, I found out that I was supposed to order the fiber insulating washers separately! I did not know that. I assumed the jacks came with everything needed to install them.

You have to order two washers as shown below:

INSULATED FLAT WASHERS
Insulated flat washer for headset. microphone jacks. ACS P/N 04-00975

INSULATED SHOULDER WASHERS
Insulated shoulder washer for headset/ microphone jacks. ACS P/N 04-00976

I am glad I found this before I finished my installation as the shoulder washer required drilling a slightly larger mounting hole.

I am sure this has prevented many hours of troubleshooting noise issues later.

bpattonsoa · #2 11-08-2013, 08:45 AM

I think that the correct washers came with the jacks I ordered from Stein. Be sure to verify they are properly installed with an ohmmeter.

I don't use them in any case. I mount the jacks on a piece of 1/16" printed circuit board material and then mount it in the aircraft. In my -10, both the front and rear seat jacks are in the Aerosport center console. The P.C. Boards have nut plates so the console can be removed leaving the Jacks mounted to their boards.

I got the board material ( without copper) from Digikey. PC6-UNCLAD-ND

rleffler · #3 11-08-2013, 09:02 AM

I'm probably stating the obvious, but to help some of the newcomers......

For those using Aerosport Products carbon fiber products (or any other vendor's carbon fiber products), carbon conducts electricity. Be sure your jacks are isolated.

Get an ohm meter out during installation to validate that the jacks are isolated. I had one strand of carbon fiber that managed to get by the fiber insulators. This will save you many headaches later. Trying to find a ground loop after you have everything back in the plane is a royal PITA.

bob

Tumper · #4 11-08-2013, 09:35 AM

I got this tip from the VAF site a few weeks ago so the credit needs to go to someone else. It saved me the problems described above.

Go to PS Engineering?s web site and on the support page there is a PowerPoint titled ?AudioSys Installations? under the ?Harness Building Training? paragraph. It was very helpful.

Good Luck

Rupester · #5 11-08-2013, 10:24 AM

I got my headphone jacks and comm wiring from Stein. He included detailed instructions and jack wiring diagrams, including where the fiber washers go. Otherwise I was clueless.

dhmoose · #6 11-09-2013, 01:26 AM

Bob...you saved me some headaches! I just finished my jack installs in the Aerosport arm rest. The entire time, I thought about how I didn't need the fiber washers since I wasn't installing in the metal airframe. I totally forgot about the conductive nature of CF! I took my ohm meter out to the shop and sure enough, I need the washers.

Thanks again!

rleffler · #7 11-09-2013, 04:54 AM

Quote:

Originally Posted by dhmoose

Bob...you saved me some headaches! I just finished my jack installs in the Aerosport arm rest. The entire time, I thought about how I didn't need the fiber washers since I wasn't installing in the metal airframe. I totally forgot about the conductive nature of CF! I took my ohm meter out to the shop and sure enough, I need the washers.

Thanks again!

I'm glad my post was of assistance.

The other good news is that the composite material that the arm rest insert is made out doesn't conduct electricity.

The only issue I'm having is locating a source for a fiber washer with a 1/8" ID for my music jack. I may have to end up making one. Fortunately I've got until I finish Phase I before anyone needs music in the back seat.

Bob

Snowflake · #8 11-09-2013, 08:36 AM

Bob, you might have better luck with a teflon or nylon washer for your music jack. We have shoulder washers in both materials at my office, they're a standard off-the-shelf part from McMaster. They're also too small for this application, but I know they are available in many sizes...

dhmoose · #9 11-09-2013, 09:14 AM

Interestingly enough, while the mic and phone jacks all grounded to the composite of the arm rest, the music jack did not and I'm not sure why.

rleffler · #10 11-09-2013, 03:51 PM

Quote:

Originally Posted by Snowflake

Bob, you might have better luck with a teflon or nylon washer for your music jack. We have shoulder washers in both materials at my office, they're a standard off-the-shelf part from McMaster. They're also too small for this application, but I know they are available in many sizes...

duh...... I should have thought of that. I have a whole drawer of them at the hangar too.

Thanks,

Bob