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!