20m Roof Vertical
20m 1/4 wave vertical, using the Colorbond roof as the ground-plane.
This antenna has gone through several iterations, and is not currently finalised. The previous designs have included:
2x 3m sections of aluminium tube. Was considered to be not structurally in high winds.
3m section of aluminium tube topped with 2.7m stainless steel whip. Never properly tuned. Utilised split conduit insert into the base of the tube to isolate it from ground, however this was showing signs of fatigue.
Hamstick. Low efficiency.
Base-loaded 2.7m stainless steel whip. Reasonable efficiency.
Modified Station Master. Slightly too long and difficult to adjust (cannot be tuned in situ).
The next iteration is to replace the top sections of the Station Master with a 2.7m stainless steel whip. This will reduce the wind loading.
I'm also planning to install an ATU at the feed point of the antenna for multi-band capability.