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Tom Waid
12-12-2012, 04:28 AM
Nice panel Tom.
I was at that point about 1.5 months ago and figured I have it wired in a few weeks. Its now 1.5 months later and I'm still not done wiring, but close. Allow plenty of time, the intercom wiring is a bear. I scrapped out my first intercom wiring harness and started over due to some poor solder joints. In hindsight I think buying the PS Engineering factory made wiring harness (at about $350) would have been a good deal, plus it is the only way they will give you a warrenty.

Jim

Thanks, I won't be wiring for a few months. After reviewing most of the wiring issues with a good friend who is my avionics guru I became convinced that it's going to take some time. Your post confirmed that.

jiott
12-12-2012, 12:29 PM
Having a friend or resource who is an avionics guru will really help and save time. I had no one except an electrical engineer friend (not avionics).

I previously posted how great the Sumitomo solder sleeves were for this kind of work with shielded wire. I have to back off on that post and say that they were the reason I had to scap out my first intercom wiring harness. I found that there is not enough solder in the little ring to saturate the shield and some pigtails you insert into the sleeve, so the solder joint becomes kind of questionable. By pulling on the pigtail I found that some of them came loose rather easily. So I redid the whole thing. The second time around I made sure my pigtail and any bare wire was pretinned and then added solder to the joint before I put on the solder sleeve. This gave very strong joints but kind of defeats the purpose and convenience of the solder sleeve. Being a beginner at this I probably wasn't doing something right the first time around. Just be aware that there isn't much solder in the ring in the solder sleeve. I think hand soldering the joints the old way and then covering with shrink tubing is still a good way to go. Good luck.

Wiring everything else (other than the intercom & headset jacks) is pretty straightforward.

Jim

DanB
12-13-2012, 02:52 AM
I made this thread moving a soldering discussion from the "Show Us your panel".

DanB
12-13-2012, 03:04 AM
You may want to reconsider making solder terminations for your build. You should find much information on using wire crimpers with pidg connectors made specifically for our applications. Do a search here as well as the internet. Many of the builders who have much more experience than I may want to chime in with a little help / tips. John P, I think I remembered you discussing the approach earlier.
Best wishes.

Dorsal
12-13-2012, 04:20 AM
I did not use any solder in my panel (at least when it comes to wire connections). In general using solder on a connection that has the potential to flex is risky. I was always told that solder will make the joint rigid and prone to breaking.

jiott
12-13-2012, 10:25 AM
The solder joints I was referring to are on the PS Engineering intercom at the 25 pin D-sub connector. You have to terminate the wire shields to one of the wires in the 3-conductor cable and also to a ground pigtail which daisy chains to about 8 other cable shields at the D-sub connector. There is very little room here for crimp terminations. The installation info from PS Engineering says to solder these joints and shows the use of solder sleeves. I agree about avoiding solder terminations and have used crimped terminals everywhere else for the reasons Dorsal gives. But in this one area I was just following the book.

I also soldered my wires to the headset jacks because that is what the PS book showed. I really wanted to use the crimped pidg faston terminals here but couldn't find a size that fit the jack spades. The female spade terminals were either too wide or too narrow. Is there a special size made for headset jacks? Or maybe the PS Engineering jacks are oddball?

Jim

n85ae
12-13-2012, 12:11 PM
If you must use solder connectors, you should solder fill all the cups first,
then wick out all the solder with de-soldering wick. Tin your wires, and trim
them so fully inserted in the cups you have 1x wire diameter between the
cup and the stripped insulation. Insert the wires in the cups, and then
heat the tinned portion of the wire AND the cup at the same time with
your iron. Adjust you iron so it will melt the solder quickly, but no hotter
than that. Quickly flow in enough solder to create a nice fillet between
the wire and the cup, and get off the wire with the iron asap. If you heat
too long, or too hot, or move the wire while it's cooling you will get a
poor solder joint. Then you should scrub the connector clean of all flux
with alchohol. You should then put heat shrink sleeve over the solder
connector and wire to support the wire at the joint.

If your solder joint after cleaning is nice and shiny you're probably good.
If it looks like aluminum color it needs rework for sure. IF you can pull ANY
of the wires you soldered out .... Then you should abandon the wiring
project entirely and seek help from a builder who knows how to do it
correctly. EVEN a poorly done solder joint should never be able to pull
the wire out :)

I was an avionics tech before I discovered computers pay a lot better.

Regards,
Jeff

jiott
12-13-2012, 01:28 PM
Thanks for the info on solder cups, but my problems occurred about 1" outside the connector housing where I was terminating the wire shields to ground pigtails. Inside the connector housing I crimped the D-sub pins to the wires.

Jim