As I look around the Internet for information on building EFHW UnUns, I see the ratios of 49:1 and 64:1 appear quite often. I get that these are the squares of 7:1 (21:3 or 14:2) and 8:1 (24:3 or 16:2) toroid windings, so I so know how the numbers are derived. What I have yet to see is someone make an UnUn with a 22:3 (7.3:1) or 23:3 (7.7:1) secondary to primary turn ratio, which would give a 54:1 or 59:1 UnUn ratio, respectively. I also see a fairly broad range for impedance values of an EFHW antenna as ranging from 2500-6000 ohms at the feedpoint, with 3000-5000 ohms being a more widely quoted range, so I get the fact that by the time that you reduce the impedance of the antenna on the transmitter side of the UnUn that it's "close enough" to 50 ohms that it doesn't much matter whether you're using a 49:1 or 64:1. I guess the question that pops up in my puny little brain is why our community mainly uses whole integer values for turn ratios. Does it give better results at the UnUn, or is it for a different reason, perhaps being that the math is just that much easier?