Last year for Field Day I built a 6 meter, 4-element Yagi-Uda antenna for the W5YA team. I never tried to match the antenna for 50Ω, and it compared poorly to Doc’s Hex Beam antenna. This weekend, in anticipation of FD 2014, I decided to finally try and match the antenna. I tried several designs. My initial try was a hairpin match, which brought the 100Ω impedance up to 200Ω. Then, I tried a 75Ω, 1/2 wavelength coax transformer as a 4:1 Balun. I played with this a lot, but could not get it to match well enough.
Today I tried a parallel 75Ω match based on this page. Based on my Yagi dimensions, this showed a resonant frequency around 48 MHz. I shortened my driven element whips about 2″ and brought the antenna to a perfect (enough) match!