This antenna is made from either an old CB whip or a stripped-down 2m 5/8 whip. When you strip down and re-shrink an antenna, be careful because some heat shrink tubes can change the antenna’s resonance, especially with helical windings. You can use a piece of 20mm conduit for the former of L2 with a few adjustments. Start by building the antenna roughly to size and adjusting the 6m section below L2 first, then move on to the 10m adjustment above L2.
Article by VK5AH