[TowerTalk] HDBX-48 figures for 90 mph zone

jcjacobsen at q.com jcjacobsen at q.com
Wed Dec 7 14:50:38 PST 2011


How do to all, 

All this HDBX-48 at 90 mph talk got the old Grey matter/hard drive working. First off: YMMV........ Also, this is all from my feeble memory. 

BUT with that said, I remember back in the '90's a local ham paid a local engineer to run the numbers on a HDBX-40 with a Hy-Gain 391S at the top. The 391S is the "Famous" TH-7dx, 9.4 sq ft area with a 24' boom. 

The numbers he came up with "proved" survival at 80 MPH........and the engineer said the antenna would probably fail b4 the tower did. It was also pointed out that the restriction of "booms no longer than 10' on BX series towers" was just that. It was printed on the page for the BX-64 64 foot tower, or any BX tower. No numbers were provided for HBX or HDBX towers. 

I myself had a KLM KT-34A on a HDBX 40 for a few years with no problems. (abt 7 sq ft and 16' boom). 

Like I said, YMMV, I have nothing to prove this, and even if I did, the paper probably wouldn't be valid today. As others have said, you just may have to pay a local engineer to run the numbers on your installation to be safe, and to satisfy the local building dept........ 

Later 
73 es GDDX 
K9WN Jake 




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