M

mantry

Well Known Member
After an enjoyable trip to Oshkosh this year when my lovely wife surprised me by telling the BOSE guy "They sound nice....We'll take 2!" left me speechless. They haven't been delivered yet even though we paid for them at Oshkosh(Another story)

The current headphone jacks are mounted on the sides behind the seats so it would make the most sense to mount the LEMO jacks right next to them. Here are a few pics to show my mounting ideas:

9u6814.jpg

and
dgqz5f.jpg

and
sngk8j.jpg


I am going to mount the Bose power jacks right next to the existing jacks. On the pilot side the tie down ring storage spot is kind of in the way but that is ok. If I have to remove the BOSE jack prior to removing the tie down ring that will be just fine. I will try to get them as close to the others as possible and hopefully that will let the tie down ring clear.

I do have some questions that I would like some additional input on:

My plan is to get the jack as close to the others as possible.

Then I will dress the shielded wires and solder them right on the adjacent jacks.

Q1. I wonder if the shields are grounded on the existing jacks?(somewhere on the other end? I didn't build the aircraft) Do the shields on the new jacks need to be grounded or because they will only be 6" long and won't be near any other electrical it won't be a problem?

Q2. The Adel clamp that is the strain relief for the existing jacks, should I get a bigger one to contain the new set of wires? Source? ASP?(Aircraft Spruce) Anyone know the size of the existing one? and how bigger I should go? (I'm not even sure how they are sized...)

Q3. If I buy a bigger Adel for the existing jacks, should I use the old clamp and put it on the new wires? Or who cares about a 6" loop of wire? If I add a clamp should I stack the two clamps on the existing bolt or drill a new one?

Q4. I need to get power and ground to the new jacks. Should I run both sets all the way forward to the fuse block and the FOT or would it be ok to crimp them together where they meet in the center tunnel or run one side over to the other and splice there and then run forward?

Q5. Looking at the jacks again maybe I need to just pull the wires from the shield and make a 2-4" loop and solder the phone/mic wires to the existing Jacks and then sneak the power and ground through the existing Adel clamp.

Thanks in advance guys, so nice to have the resources of this group available to us newbies.
 
See the answers to your questions below:

mantry said:
After an enjoyable trip to Oshkosh this year when my lovely wife surprised me by telling the BOSE guy "They sound nice....We'll take 2!" left me speechless. They haven't been delivered yet even though we paid for them at Oshkosh(Another story)

The current headphone jacks are mounted on the sides behind the seats so it would make the most sense to mount the LEMO jacks right next to them. Here are a few pics to show my mounting ideas:

9u6814.jpg

and
dgqz5f.jpg

and
sngk8j.jpg


I am going to mount the Bose power jacks right next to the existing jacks. On the pilot side the tie down ring storage spot is kind of in the way but that is ok. If I have to remove the BOSE jack prior to removing the tie down ring that will be just fine. I will try to get them as close to the others as possible and hopefully that will let the tie down ring clear.

I do have some questions that I would like some additional input on:

My plan is to get the jack as close to the others as possible.

Then I will dress the shielded wires and solder them right on the adjacent jacks.

Q1. I wonder if the shields are grounded on the existing jacks?(somewhere on the other end? I didn't build the aircraft) Do the shields on the new jacks need to be grounded or because they will only be 6" long and won't be near any other electrical it won't be a problem?

A: Shields are not grounded at the jacks end. You can forget about shields when you splice in the LEMO connector

Q2. The Adel clamp that is the strain relief for the existing jacks, should I get a bigger one to contain the new set of wires? Source? ASP?(Aircraft Spruce) Anyone know the size of the existing one? and how bigger I should go? (I'm not even sure how they are sized...)

A: Look on the Adel clamp at the last number, it should be a 4 or 5 or 6. This is the diameter of the grip in sixteenths. So a 4 would be 1/4". Use that as a guide to see what size you need to replace it with to grip all the wires together. Aircraft Spruce is good for the clamps.

Q3. If I buy a bigger Adel for the existing jacks, should I use the old clamp and put it on the new wires? Or who cares about a 6" loop of wire? If I add a clamp should I stack the two clamps on the existing bolt or drill a new one?

A: See #2 above. You really only need one Adel clamp. The loop will be fine.

Q4. I need to get power and ground to the new jacks. Should I run both sets all the way forward to the fuse block and the FOT or would it be ok to crimp them together where they meet in the center tunnel or run one side over to the other and splice there and then run forward?

A: Whatever is most convenient. Just remember, the fuse is protecting the wires, so make sure all the wiring is downstream of the fuse.

Q5. Looking at the jacks again maybe I need to just pull the wires from the shield and make a 2-4" loop and solder the phone/mic wires to the existing Jacks and then sneak the power and ground through the existing Adel clamp.

I would splice the new wires from the LEMO right to the jacks as you suggested. (Use the Bose schematic that came with the LEMO connector.) I would pull out both existing jacks, remove all the solder connections and re-solder with the new wires. The most difficult part will be to figure out where all your little pieces of shrink tubing will go before soldering. Bring in your power and ground wires, splice to the LEMO connector wires and you're done.

Thanks in advance guys, so nice to have the resources of this group available to us newbies.
Click to expand...

Don't forget to reinstall the jacks using the phenolic washers with the little shoulder that keeps the jacks isolated from your panel ground.
 
Last edited:
Thanks Pat!
Q5. Looking at the jacks again maybe I need to just pull the wires from the shield and make a 2-4" loop and solder the phone/mic wires to the existing Jacks and then sneak the power and ground through the existing Adel clamp.

I would splice the new wires from the LEMO right to the jacks as you suggested. (Use the Bose schematic that came with the LEMO connector.) I would pull out both existing jacks, remove all the solder connections and re-solder with the new wires. The most difficult part will be to figure out where all your little pieces of shrink tubing will go before soldering. Bring in your power and ground wires, splice to the LEMO connector wires and you're done.
Click to expand...

I'm not sure if you are talking about removing the existing Mic/Phone jacks... I would like to have both sets of jacks available. If that is the case are you saying it would be easier to desolder/remove the existing wire from the existing jacks and then solder them back on along with the new wires going to the LEMO? That is a thought, otherwise you know it is just going to be to "tin" the new LEMO wires and piggy back them on to the existing lug on the jack.

ROGER on the shrink tube! I noticed that right off the bat!

Also a sideline question... I've seen butt splices with just 2 wires and the butt splice crimped in. Then I've also seen the same butt splice and then a piece of clear(or non clear) tubing over the top of that and either zip tied or thread laced. What is the best practice for that? Reasons?
 
Yes, I would remove the existing jacks just to make it easier to de-solder and re-solder with the new wires and work all the heat shrink in. Just makes it easier if you can get the jacks mounted on a pin vise or something similar to do the work, then put everything back.

I'm not a big fan of butt splices, I would rather use a small solder sleeve or just solder splice and shrink tube. But using butt splices as you describe is pretty standard. If you need to reverse the direction of the wire, put both wires into the same end of the butt splice. The shrink tube is to protect the other end from a short, and then the zip tie is just for support.

Absolutely you want both sets of jacks available! That's how I have my airplane set up--gives you a lot of flexibility. Mostly for other pilots who come along that don't have LEMO headsets.
 
I was studying the BOSE LEMO jack install, specifically the wiring diagram as supplied by BOSE. They are tying the BLACK - PIN 2 GROUND (which I assume runs the ANR) to the HEADPHONE JACK's AUDIO Ground. Anyone have comments on this? I was assuming/planning on running both the POSITIVE and the GROUND up to behind the panel and putting the POSITIVE on a un-used fuse tap and putting the GROUND on a GROUND TAB on the FOREST OF TABS.

Any comments on which way is the best/easiest to accomplish? I have the wire and if I plan on running the POSITIVE all the way up, running the ground along with it won't be a big deal. But, better if I don't have to! :)
 
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