Printable View
When connecting the oxygen mask microphone U173/U to the microphone cord with a U172/U connector, are these pins polarized or can they be plugged in either way? It is just grounding the mic. wires. I can't see how they could be polarized. However in some airplanes when I plug into the airplane all is good and on some airplanes when I plug into the airplane squealing results. Me or airplane?? Am I looking at the wrong thing? Could it be airplane wiring?
Seems like if polarity was important, they would have designed the individual posts differently. In this shot, they look identical
Attachment 9533
Oddly, on another shot I took, the posts are actually different...but STILL not different enough for a polarization guide.
Attachment 9532
If you can, in the squealing cases disconnect the U173 and turn it the other way.
Ron Wanttaja
If it's an old fashioned carbon or dynamic microphone, polarity shouldn't matter. If it's a modern electret mike, polarity will matter.