Here are the key 'tricks' that we have evolved to enable the Supra mains cable to be effectively constructed with a MK Toughplug and Wattgate 320 IEC. They are all to do with dealing with a cable that is considerably 'fatter' than a conventional 13A cable.

The first thing to do is to make 2 modifications to the standard MK Toughplug shown below.

You will need to remove and cut down the nylon cable retainers which leave a gap too small to enable you to insert the Supra cable. Some people suggest removing them altogether but then you have no retention of the cable which we feel is dangerous.

You cut a strip off with a knife or or sharp wire cutters as shown on the right. If you leave a rough surface then clean this up with a file or sandpaper.

You next need to remove a nylon post with the plug cover which will stop the cover from being fitted later as it will foul the Supra cable.

This is cut off with a pair of wire cutters.

You are now ready to prepare the cable. At the MK end you should cut the Earth to 4cm and the live and neutral to 2cm. Then remove the insulation for about 5mm.

We find it best to remove the brass fittings, attach these to the cable ends and then refit the brass fitting. It is a tight fit and you need to place the cables carefully. It is possible to arrange the cables neatly so that the cover can screw on without being under pressure.

When preparing the Wattgate end, we cut the conductors to an equal length of 2cm, again with 5mm of insulation removed. We fit the cable in the Wattgate cover before removing the insulation in order to avoid splaying the conductors.