This antenna matchbox is available assembled from the Emergency Amateur Radio Club of Hawaii, or you can simply follow the construction details in the PDF. While the assembled unit appears weatherproof, I think it wold be best for temporary/portable applications.
This could be a good club build project, providing members with a pretty reasonable HF antenna, perfect for trying out FT8 or other weak-signal digital modes supported by Joe Taylor’s WSJT-X software.
The Assembled version, with a bit of wire for the radiator, is available here: http://earchi.org/proj_homebrew.html
Assembly Instructions are available here: http://www.earchi.org/92011endfedfiles/Endfed6_40.pdf