I have built several of these, found most of the hardware and wire(used thermastat wire instead of enameled) at a big box hardware store , sourced my toroid and pl-259 elsewhere. Used a 4x4x2 outdoor junction box. They work great with a tuner.
OK for the money, I suppose. But in rainy environments, it will definitely leak water and see condensation form. But you can grease the connections up to limit ingress, and I would always drill a modest hole in the lowest point of the box, however it's mounted, to allow moisture out.
I think half of the stuff in the "kit" is unnecessary. Just get the wire and a ferrite core with a known value, and spray it with flex-seal. I made a 64:1 with a type 52 core for $10.......
Hi, If you build a random length end fed wire then you could use your kit to build a 9:1 balun for it but the EFHW needs a 49:1 transformer to work. The half wavelength wire has a very high impedance on it's end and requires the 49:1 to bring it down to match your 50 ohm coax. Some use a 64:1 xfmr. Don't forget to use a 1:1 to help block CMC on the feedline. Install it in the feed line at the outside entrance to the shack. You can buy a 4x4x2 wx proof electrical junction box at Lowes or Home Depot (or online) for using a FT240 size core. It works great. You can also build your 1:1 on a FT240-43 and use a electrical junction box for it. Another good place for a kit or kit parts is HF KITS which is in Europe. They have good stuff but the exchange rate in currency and shipping means it gets a little expensive. Still there on line instructions for their kits may help someone. 73 and keep up the good work! Experimenting with antenna design is a great part of being a Ham! I love it!
They were much less than $10. My entire sha-bang was $10. Smaller size 1.5" cores. Ham-fests are your friend......