is a short helical antenna for the 160 metre amateur
radio band. The top hat is just 12 feet above the ground.
It is loaded against two 3 foot earth rods.
Inspiration for this antenna came from the book
On SSB running a power of 30 watts PEP, I have had good signal reports from Somerset, Cornwall, South Wales, and Scotland.
Of course reports are a couple of s points or so less than a full quarter wave but it's a perfectly usable antenna given fair conditions.
If you want to know how I made it click next.