Today I experimented with building a 64:1 unun for an 80-meter EFHW.
My initial attempt involved 3 primary / 24 secondary windings, but I quickly found that this took up too much space on the small toroid I was using.
After some adjustments, I settled on a 2 primary / 16 secondary windings, adding a 100pF capacitor. This configuration was inspired by resources like KM1NDY’s DIY linked EFHW 64:1 antenna guide.
I’m now successfully running my home EFHW antenna on 40 meters without needing a tuner. On 17 meters, the SWR is a bit high, so I engage the tuner for that band.
This setup reminds me a lot of my previous 71-foot random wire antenna with a 9:1 balun. I’m noticing a significant increase in the number of signals I’m receiving, which suggests this new EFHW might be a considerable improvement over my old 107-foot EFRW.