Hi all,

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

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

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

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

Suggestions would be appreciated.

Best wishes,

Chris Tidy