HOW TO TERMINATE PLAITED CORDS
Platted cords were, as you know too well, cut off at the wall box by
the 1000s, leaving collectors with a problem. Leads are valuable but how do you effect a
good repair? Crimps...waste of time, solder...won't wet the copper.
If you have a copy, look at page 170 of J Atkinson, Telephony Vol 1,
by Pitman & Sons published 1948 last reprinted 1964, which shows the make
up of a typical lead. This gives some clue, together with an inspection of an intact
lead, of how to make a termination.
It may seem complex from my description, but with practice it takes
about 20minutes to re-terminate a wrecked three core lead. I can say that having
terminated not less than 250 leads this way, it most definitely works and the failure rate
is about 1 in 100. Clearly, the finished job can never match the GPO termination, which
was machine done, but it is close and as I state above, it does work.
Tools and Equipment Needed
Note! My description
assumes that a brown lead is being re-terminated.
Then, to stop everything coming undone, hold the three cores together
at the point were the plait stops and wrap about 50-100 turns of brown cotton around to
hold it all together. Then with 3 or 4 half hitch knots tie off your wrapping. You should
now have a smooth wrap of brown cotton at the end of the plait, with three 75mm tatty
ends! To finish off the wrapping and to make sure it does not come undone use melted
beeswax (used on the originals, applied by brush), or Evostic, smelly but effective!
Strip about 50mm of the 0.75mm2 copper cable using the
strippers, but leave the 20-25 exposed conductor strands attached to the cable. The
technique is wire wrapping, bend about 8-10 strands of copper on the cable
away from the others. Then select your tatty end and place the 8-10 strands against the
exposed tinsels/silk strands and wrap the copper cable strands around them about 6-8
Very carefully place your wrapping on a heat resistant mat ready for soldering. The secret of soldering is a clean hot iron, which is already lightly tinned. Place the iron against the wrapping at the same time as the solder, capillary action will pull solder onto and into the wrapping. Dont worry about bits of silk, they burn away and a good copper/copper contact is made.
By Peter Bailey
Last revised: December 04, 2010