The link I’m sharing here is about as technical as I get. But I imagine it will help many of you as you try to improve antennas and your station’s range. The credit for this goes to VE7BQH. He must have done a ton of work creating this.
http://www.sm2cew.com/gt.htm has detailed performance tables on well over 100 2 meter and 6 meter yagis. Make sure to take your time, and scroll down and read the detailed notes. The 2m yagis are on the top half of that link, and the 6m beams are below.
Newer guys might think, “Where can I go and buy these yagis?” In many cases, you can’t. The SSB/CW/EME side of V/UHF has a very high concentration of technically proficient guys. Many of these yagis were built by hand. But there are commercially-available yagis in these tables. Like I said, scroll down to the “notes” portion to see “Manufacturers/Designers Legend” I’m sure if you use Google to search for the other antennas, you will get some promising leads.