5 PIN XLR Removal/disconnect
 

Good afternoon,

im trying to figure out how to remove/disconnect the ‘5th’ pin. My company requires the 5th pin be disconnected for an XLR 5 pin.Can anyone shed any light?
Many thanks

My cheat sheet for headset connections shows pin 5 of an XLR-5 being used for the headset + DC feed for noise cancelling (if the headphones are so equipped). Lacking an aircraft DC supply, the headset would need internal batteries to power this. Some are equipped with a switch (battery/aircraft power). Switching to the battery position would disconnect the pin 5 feed from the aircraft. If they trust you to keep this switch in the proper position, this may suffice. If not, you will have to open the connector backshell (assuming it's not a molded plastic plug), locate pin 5 and unsolder or cut that wire.

It might be possible to have someone with a modicum of electronics tech skills to put together a male to female XLR-5 adapter with pin 5 not connected. So, no modification to the headset. But again, they would have to trust you to plug the adapter in line. If they didn't trust you to flip the battery switch ....

In the U.K. “Flightstore” (Other suppliers are probably available ) supply an XLR to 2 plug adaptor with pin 5 already disconnected. I’ve been using one of these on B737 for the last 15 years with a Telex 850 ANR headset which runs off the aircraft mic bias current.
Headset works fine, and four airlines I’ve worked for have been happy with it, all with the same requirement as yours.

I have an answer. When the company ask if you have disconnected pin 5 in your headset, you say yes.

Pardon my ignorance, why would your airline demand the fifth pin be removed?

This avoids inadvertently short-circuiting the aircraft XLR socket which can lead to Remote Electronics Unit failures on the 737.

I asked FlightStore the exact same question but they could only read what it said on the box. They past me on to the boss there and same thing they knew nothing about anything. In fact the first guy I’m not sure could actually read! Adams aviation will know