Problems soldering 2.1 mm DC line socket

That's the problem. You need a 60 W iron and you need to work FAST! Anything you can do to make the solder stick faster will help.

The trick to soldering any of these small connectors - DC power, audio or RF - is to fit a mating plug or socket to the item you are trying to solder. Then, with it all held still in a small vise or helping hand, tin the connections. Even if the centre insulation does soften, the pin / socket will be held in place by the mating connector that you've fitted. After tinning the contacts, tin the wire ends, then solder the wires to the contacts as 'touch' joints. Although the conventional soldering wisdom is that a good mechanical joint should be made, before applying solder, in the case of small connectors, a touch joint is good enough, as the plug's strain relief will normally supply enough mechanical stability to the joints.

Arfa

I have a 40 W iron and a 75 W iron too. The 75 W is far too unwieldy, so I'll try the 40 W next time.

I thought of this just a few minutes ago while I was looking at the melted plug. Neat idea. I wish I had thought of it earlier!

By the way, does anyone know of any 2.1 mm line sockets made from heat resistant plastic?

Thanks for the help.

Best wishes,

Chris

No reason they aren't made but if you can buy the original connectors, someone somewhere is soldering them OK.

Hello, Christopher! You wrote on 13 Nov 2006 09:32:48 -0800:

CT> I recently bought a 2.1 mm DC line socket from Maplin (part no. JK11M) CT> so I could power a project using a plug-in power adaptor (wall wart). CT> Soldering a lead to the outer coaxial contact was no problem, but when CT> I tried to solder a lead to the inner contact, the plastic insulation CT> melted!

CT> I'm not a novice to soldering and I wasn't using an inappropriately CT> large iron. The iron I was using is an Antex rated at 18 watts, CT> although it isn't a regulated iron. I didn't touch the plastic CT> insulation with the iron. The joint clearly didn't get hot enough to CT> melt the solder, so I reckon the plastic must have melted at less than CT> 180 deg. C.

CT> The Maplin socket design is bad in two ways. Firstly the insulator is CT> made from a thermoplastic, and secondly the solder bucket for the inner CT> contact is right next to the plastic insulator.

CT> So I have a few questions. Are all 2.1 mm line sockets like this or are CT> there better designs out there? If there are better ones available, CT> where can I get one from? And how are you supposed to solder these CT> sockets with thermoplastic insulators?

CT> Suggestions would be appreciated.

CT> Best wishes,

If you have space, use of a small crock clip positioned just a little downstream of the intended soldering point, can act as a heat sink and carry some of the heat away, give yourself just enough free metal to make a quick joint.

With best regards, 3T39. E-mail: snipped-for-privacy@hotmail.com

"3T39" wrote in news:4558e933$0$18053$ snipped-for-privacy@news.zen.co.uk:

Yes, a heat sink is a good idea, but as Christopher originally stated, the point he is trying to solder is right next to the plastic that melts, so there's no room for a clip.

The idea of inserting the mating connector probably provides a little heat sink. If you want a larger one, try suspending the connector (solder connection up) in a cup of water, so the water covers the plastic, but the solder connection is out of the water. That should keep the plastic cool while you solder. Just dry out the connector before you use it.

I bought two more sockets from a different supplier and tried again. This time I used a 40 W soldering iron and a mating plug as a heatsink. The results were acceptable, but only just. These sockets also use thermoplastic insulators, and both suffered a little damage. Because the solder bucket is right next to the insulator, it seems that the insulator will inevitably be softened, and that the mating plug is essential to hold the central pin in place. For anyone trying to solve the same problem in future, the mating plug is the key.

It's a pretty pitiful piece of design really. An extra 5 mm between the solder bucket and insulator or a change to a heat resistant plastic would make all the difference.

Thanks for the help.

Best wishes,

Chris

Turned, solid brass pins, used as a plug will help ! Mine are 2" long and provide a good heatsink for the centre pin ! It also helps that you can clamp the brass pin into a vice to hold the assembly steady.

But I do agree, a better plastic would help. I also get this softening on SO239 connectors that do not use teflon or similar, as the insulator.

I have recently made up 6 leads using these connectors and have not run into any problems - a hot iron, tin the tags and the wire first, and add just enough heat to sweat the wire to the tags. If I was worried about too much heat I would just hit the joints with some cotton wool dipped in metho to get a rapid cooldown

My connectors come from DSE/Tandy - nothing special

David

Bar> Christ>