Does anyone know if a non-metallic pole approx. 4 m long is available that i can use to mount a vertical 10 m 4 element yagi ? that is not wood, PVC or fiber glass as these are either too heavy or not strong enough. My location is Melbourne in Australia.
You could use a metal pole broken up with a few insulators.
One at the boom itself, and one near the ends of the elements, perhaps one more 2.5 m below the antenna, or at the base of the pole.
Don't forget to route the feed cable out around the back of the antenna far from the reflector, or cover it in ferrite beads if it runs down the pole.