Dear Possibly Informed Person:

I have looked at several online pages that describe calculations involving Yagi antennas. However, when I apply these methods to the cubical quad (my antenna of interest) I get numbers greatly higher than those listed by commercial manufacturers. For example, a Cubex 3-el, 5-band gives me 10 sq ft, just counting the boom and spreader arms with no wire, spiders, or Dacron support line, and I'm using the 2/3 multiplier for round members. They report only 7.4 sq ft. I've read that manufacturers exaggerate, but this seems more than that. What am I missing?

Thanks,

Dan N8PPQ