Measure 127.5cm down the cable. Strip the wires back to this point and solder the wires together. You should now have a piece of 300 ohm cable, 127.5cm long with the two wires shorted together at both ends. Measure down the cable 48.5cm from one end and cut through ONE of the wires. Measure another 2.5cm from this point (51cm from the same end) and cut through THE SAME WIRE. Remove the 2.5cm strip between these wires. You should now have a length of 300 ohm cable, 127.5cm long with both ends shorted and a 2.5cm strip missing from one of the wires only.
This antenna, as shown, is designed for indoor use or for outdoor use in dry conditions. Some designs specify the use of slotted black coloured 300 ohm cable for outside use but we have had reports, from club members, that the capacitance of this cable also changes during wet conditions and this adversely affects the performance. Conclusion: do not use 300 ohm cable for outdoor use unless you keep the cable dry. For example, you could mount the cable in a plastic tube.