What to use for a Mast on a Rohn HDBX48 Tower

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by W4MRP, Apr 17, 2019.

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  1. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    As long as it's a 2" OD or larger diameter with .120" or thicker walls it should work fine for your application.

    If you haven't already, inspect the aluminum rivets on all the crossbar supports and replace any broken or missing ones.

    I would not add "more sections" not made by Rohn specifically for the purpose; these things have to taper to be structurally sound, so another base section needs to flare wider than the original one. Tilting it up with a heavy load at the top might do some damage; I'd install the tower with only the rotator and mast installed, tip it up, bolt it in place, then use a bucket truck to add the antenna(s) if at all possible. Once that large beam is installed, tilting it back down will never allow it to tilt all the way down, anyway.:)
     
    W4MRP likes this.
  2. W4MRP

    W4MRP Ham Member QRZ Page

    Very good. Thanks!

    Amazingly, there are no loose rivets! None. They are all tighter than a ... well, they're tight. That was one of the first things I looked at because I had read about that problem. IIRC, it's caused by torsional stress (i.e., twisting force from big antennas).

    Yeah. Given up on that idea. But mine was going to be made out of 1.5" 11 gauge square tubing with rebar cross bracing. It would weigh more than all the Rohn sections combined. I wasn't concerned about the fabricated bottom section. I was concerned about where the bottom section joined to the Rohn sections. But I think it's best all around to just use the Rohn unmodified (except for my tilt base).

    Yeah. Been thinking about how that would work. First step is get the tilt base working with just the bottom tower section. Then a few more sections. Then all the sections. Then with the mast and rotor. If all is well, then with the antenna. Hope it works out. It should. Here are some videos of this specific tower on tilt bases. The first one is actually an HBX tower (not HDBX) and it looks closer to 70' tall and it has a Mosley Pro67 on it. Has a custom tilt base. I think this guy has 4 HBX towers total. The second video is the HDBX on a tilt base with some other decent yagi on it. Looks like Rohn tilt base with custom raising fixture.






    --- W4MRP
     
    Last edited: Apr 19, 2019

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