If your tower is 48 ft, then it should be an HDBX and the wind loading for the antenna should be higher than 6 sq ft. , more like 18 sq ft at 48 ft.. I have the HDBX and an A4S on it. Talk to AES in Milwaukee or Cleveland, one of them had or has and BX type tower and have several Beam antennas on it. I know the sq ft rating changes as the height changes.
de Rick wn2c
According to additional articles that I've read, I believe that you might be right. And, there's a review in eham that supports your post, also. However, when I look at an image of the HDBX tower, I'm not sure if mine is an HDBX tower since there appears to be more cross bracing on the HDBX than what my tower has - I was going to add an image of the bottom section to this post but I didn't see a way to do it. But, if mine is an HDBX, then it would save me a few thousand dollars. I bought my tower used but my trusted friend said that it's a BX tower.
UPDATE: According to criticaltowers.com, my tower is an HBX-56 but I'm not using the top section. So, essentially I have an HBX-48. According to another source, my tower is actually an HDBX-48 since I'm not using the top section and since the bottom section is #8.
Anyway, this is probably moot since Rohn recommends that the boom length be less than 10 feet for all models even though there is no engineering data for booms greater than 10 feet. But, since I haven't had any problems or evidence of any impending problems I have to assume that Rohn is just being conservative.
But, I'm considering a 25G tower anyway.