I've been wiring up the headphone and microphone jacks for the pilot and co-pilot positions via my PS Engineering 1000II for the last few weeks (yes, I said weeks. It's -14 today.). Now I'm thinking I've been confused into doing it wrong. Yes, I used passive voice there.
I'm using the PS Engineering wiring harness tutorial, which you can find here, if you have Powerpoint.
Here's one of the slides.
It appears to tell me to connect one push-to-talk wire to the tip and one to Audio Lo, the barrel... ground, as I understand it. OK, fine.
Another slide shows this schematic:
So far so good? Good.
Notice that it says connect PTT to tip. Now look at this slide:
Notice the difference? In the first two schematics, it has the PTT wire on the top, indicating that it's the "tip." On the last schematic it identifies the tip as the middle.
Based on the last two images, it suggests one wire comes off the same pole as the ground (Audio LO) and the other comes off the same pole as the audio (AUDIO HI). It appears to me that the schematics in one indicate that audio_hi is the tip and on the other it seems to indicate audio_hi is the ring. In effect -- if you compare image #1 with image #3, it appears to identify a location as a "tip" in one schematic, and then as the "ring" in the other.
Or am I reading it incorrectly?
So, which is it? Let's look to Bob Nuckols of Aeroelectric Connection for help (click for larger image).
To me, that shows the AUDIO-HI wire attaching to the jack without any other wire. Which is too bad because, of course, that's not the way I did it. It's interesting to note that this particular schematic also connects at shield at the jack, which PS Engineering's tutorial says is a no-no. But that's another story for another day.
Update 7:39 p.m. - Armed with the knowledge that there are no electrical symbols here, only a physical reference, I went out to the hangar and got the jacks rewired properly. The -3 temperatures be damned.