How to solder wires to connectors

To know how to solder wires to connectors you need to know the basics of soldering which are covered in how to solder a circuit board. You may find a helping hand useful for this task. By helping hand I mean the device, not a friend to help but if you have one around they could also prove useful.

The advantage a helping hand has over that of a friend is that they hold things completely still and don’t scream when things get hot like my friend did. This is the biggest problem of how to solder wires to connectors. If everything is held still and in place the rest is relatively easy.

If you look at soldering a lead to a jack plug you will learn a few of the techniques of how to solder wires to connectors. You will also find a bigger tip will make the soldering job easier.

If you have a soldering station as opposed to a soldering iron you will probably find the job easier if you turn up the temperature by about 20C.

The task of stripping the cable may also cause a few problems if you’ve never done it before. Depending on the thickness of the cable it may be easier to use a sharp knife to take off the plastic insulation rather than a cable stripping machine. I lightly score around the circumference of the cable where I want it stripping to. You have to be careful not to go through to the copper shield under the plastic. Then lightly score from this line along the length of the cable to the end. You should use more pressure as you get to the end until you cut through the plastic. Then pull apart the two ends of the plastic. This should separate along and pull off as you get to the circumference score.

Under this will be the shield. This will usually be woven so you should unravel it with the tip of a small screwdriver to reveal the insulated core in the middle. You don’t need to take this back to far, in fact the less you take back, the better the screening properties of the completed lead will be. Just reveal enough so you can strip off some insulation off the middle core.

Twist the strands together and tin the end. Twist the unravelled screen and tin the end of that.

Now comes the helping hand. Use one part of it to hold the unscrewed jack plug. Don’t forget to put the other end of the plug over the stripped cable. It’s not a good feeling to complete a perfectly good soldering job only to have to unsolder it because you forgot to put the other half of the plug on!

Hold the cable with the other half and position the shield and core wires of the cable to the respective connections. I solder the shield connection first. I apply the soldering iron tip and the solder to the metal tag near to where the tinned sleeve wire touches it and gradually introduce more solder until the molten blob touches the cable and melts. Then take the iron away and don’t touch anything. It can take a good ten seconds for everything to set and cool and if you move anything too soon you’ll ruin a perfectly good joint.

You need to apply the heat to the metal part on the plug because that takes the longest to heat and melt the solder. If you did the cable and the tag at the same time, by the time the solder properly melted the wire insulation would have started to melt. The core can be soldered in the same way. This has a smaller metal area so won’t need as long to melt the solder .This time I usually put the wire through the hole in the tag and bend it slightly inwards. That way the joint won’t touch the screw on body of the plug. Sometimes there’s a plastic transparent PVC sleeve that slides over this to stop it shorting on the body if it’s metal. After years of trial and error this is the best way I have found of how to solder wires to connectors of the jack variety. These techniques can be adopted to solder connectors of most types.