Recently, I have begun to experiment with EFHW antennas again. I ran across YouTube videos from Steve Ellington as well as others describing matching transformers to match a 50 Ohm load to the ~2500 Ohm impedance of a EFWH. I built the matching transformer seen below by following materials from Steve Ellington (N4LQ) and Steve Nichols (G0KYA).
I located an old roll of 14 Gauge stranded wired, that I think I salvaged from my Dad's workshop many years ago, and cut a length of wire ~66 Feet long. After hoisting one end into a tree outback, I connected the antenna analyzer. After a few trims I was able to achieve a SWR of 1.2:1 on the low end of 40 meters and around a 1.9:1 in the SSB portion near 7.290 MHz.