axlr8r

axlr8r

Well Known Member
I wired a D Sub connector for two sets of jacks for my RV 8 today.
I was trying to keep the shielding close to the connector (I'm using pins)as possible, but I think the distance from the shielding to the pins is too short. As a result,there was not a lot of room to easily place the pins in the correct sockets, and in fact some of the wires going into the sockets have way too much strain on them. I all works OK, but it looks awful and is not a job I'm proud of. How much room can I reasonably have between the shielding and the connector without causing any problems. I plan on doing the job over again.
Thanks
Steve
 
What are connectors for Steve? Shielding might or might not be all that important.

Making good D-Subs takes years of practice and lots of patience - along with small fingers and good eyesight.
 
I try not to have more than 1 to 1 1/4" unshielded

but again it all depends on what it is and how close it is to other sensitive wiring.
 
D Sub

I'm making the wire runs from two sets of mic/hdph jacks to a Flightcom intercom (into a 25 pin D Sub). The distance is approx. 6 ft. After looking at Bob N's article I can see it would be a lot easier to use single stranded, shielded cable for the whole job to reduce the amount of unshielded wire at the intercom end. However, I'm using 2 lengths of 3 strand shielded for the mic and 2 lengths of 2 strand shielded for the phones. It looks stripping the shielding back about 5 in. (on the intercom end for each cable) will allow me the necessary wiggle room to alleviate strain on the D Sub pin and still have a neat job. One complication for me is having to daisy chain six grounds into one pin connection on the rear of the D Sub. I'm using solder sleeves to do that job.
I'm just worried that the 5 in. of unshielded wire might cause me some interference problems down the road.
Thanks for the info. Sorry the first post was not complete. I would have posted a pic, but I did not want to expose such lousy workmanship.
Steve
 
I think that 5" unshielded is pretty much going to give you the same results as not using any shielding at all. It sounds like you are using the correct stuff - solder sleeves and twisted pairs/triples - to do the job - it is just finicky. Daisy-chaining the grounds works well, it just takes an extra hand now and again to assemble the pieces - those little alligator clip/vice things for soldering help.

The Garmin harnesses we just assembled called for no more than about two inches of unshielded length from the pin (very little unshielded outside of the back shell).

Paul
 
For what it's worth, here's a little tutorial showing how I typically deal with shielded wire. This doesn't show how I splice multiple shields together, but if the actual process of stripping and soldering the shielded wire is what's giving you trouble, perhaps it will help: Shielded Wire Tutorial



good luck,
mcb
 
As Matt's article illustrates, you need some of these which can be purchased from SteinAir and many other suppliers:

SS2.jpg

This link will take you to SteinAir's order page.​
 
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Great tutorial

And easy to understand. Thanks for the help guys. I used the solder technique today and was able to keep the unshielded wire sections under 1 1/2 inches. It just took some time and patience and most importantly planning. It was a lot easier the second time around after getting all of your comments.
Thanks
Steve
 
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