A friend had an old GPO 300 series phone (or more likely an Indian knock off), that he asked me to fit a BT plug to. It had a woven fabric lead on it that seemed to be a kind of highly flexible litz wire - lots of very fine strands mixed in with the fabric. It took a surprising amount of effort to solder a length of more modern 2 pair flat PVC cable to the end so that I could actually terminate it into a BT plug!
However it worked nicely once done.
The way to strip litz wire is to light a small amount of meths in a tin lid, burn off the insulation of the strands in the flame, then extinguish the burning wire in the meths. (I don't see why litz would be used for a telephone (if that is what it was), as it's usually needed for high frequencies.)
ISTR I used a flame to burn off some of the fine fabric strands. Attempting not to burn back the very fine copper or oxidize it too much in the process.
I thought the idea was to burn off the insulation on the individual strands, which may be some sort of enamel, though sometimes wire for winding coils has insulation that is melted with a soldering iron.
This did not have insulated strands as such, it was more like a woven cord where some of the strands were copper, and others a file jute like material. Most of it being non metallic.
Have something to add? Share your thoughts — no account required.
Ask the community — no account required