Looking for base mount for a push up mast

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by AE7UT, May 3, 2012.

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  1. AE7UT

    AE7UT Ham Member QRZ Page

    What I have now:
    Old metal 30 ft. push up mast with a 3 ft metal strip lashed to the top. (total 33 ft)
    Held in place with a 6 ft metal pipe 3 feet in the ground and cemented down.
    Using "U" clamps to hold the push up pole to the metal post.
    Running a 138' OCFD and G5RV in two different directions.

    This was suppose to be a temporary situation until I got a tower.
    It's been 2 years of temporary. It's ugly, wobbly, and a PITA.
    It's rusted to the point it doesn't "push up" any more.
    It takes way to long to un-clamp it and lower it to mess with the antenna.
    There has to be a better solution.

    I live in rural Utah with no local mast, tower, antenna supplier.
    I would have to ship what ever I use and that is a problem with big metal items.

    What I've found:
    Rohn 34 ft Mast, Telescoping - UPS Shippable - ROH-9H50 http://www.dxengineering.com/Parts....-1B9E-47C3-8505-0BD8AFE1E78D}&PartNo=ROH-9H50
    I would also like to find a good base for this. It would be stand alone/guyed - not hooked to the house.

    I've not given up on the tower but my skills and resources are limited as to building a base for it and
    getting one up here in the sticks. Any ideas on who could put one up for me?

    Any help would be greatly appreciated. I just need more altitude and wire up.

  2. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I've installed a lot of these. Really a lot, probably more than a dozen at many locations.

    For temporary use, all sorts of things work since the guys really do all the work anyway. The base only needs to prevent the mast sinking into the ground and possibly hold the mast vertically for a matter of minutes while the first set of (lower) guys are secured and tensioned.

    For more permanent installations (where I think the mast will be in place years, not days) I always dig about a 15" diameter hole using post hole diggers, picks, shovels, etc., plant a footing mast about 3-4' into the ground, and pour concrete to hold that in place. The mast I use is 2" O.D. galvanized steel, and the H50 telescoping Rohn mast fits right "over" that (not clamped to it!), so the footing mast goes up inside the extendable mast. That way, there are no clamps or other hardware required at all and you can "let go" of the Rohn once it's planted over the footing mast, and it can't go anyplace at all. It can't tip over, and it can't sink in. The work to make the foundation takes about 30 minutes and takes maybe 2 bags of Quickrete, which will set up in 24 hours.

    Then, I install guy anchors at three locations 120 degrees apart, 30' out from the base. If you have good, solid earth (and not sand or clay), ordinary screw-in anchors work great and are very strong. For a 9H50 (which is a "shortened" version of the original H50 sold by Rohn for about 45 years, made of shorter sections so they can ship it cheaply via UPS), guying at three or four levels is absolutely required, so this is nine or twelve guys. When supporting wire antennas, I would never use wire for the guys: Only good ropes. I usually use double-braided Dacron 3/16" rope from Synthetic Textiles. It's strong, light, weatherproof, UV resistant, and hardly stretches. I use turnbuckles at the bottoms of all the guy ropes for tensioning.

    Such an installation including mast erection and securing and tensioning all the guys takes me about 60 minutes, working alone. It's not a big job.

    For wire antennas, I use a pulley at the top of the mast so raising and lowering a wire antenna is just a matter of untying a rope and letting it down, or pulling on the rope to hoist it back up -- no need to ever lower the telescoping mast. I usually attach a "cleat" near the bottom of the mast to tie the hoist rope around (like you'd do on a boat).

    Those cost about $3 from Home Depot, or a better one is about $25 from a marine supply store (where everything is either brass or stainless).
  3. AE7UT

    AE7UT Ham Member QRZ Page

    Thanks so much for the reply!
    Just what I was looking for.

  4. KF5FEI

    KF5FEI Ham Member QRZ Page

    In case anyone forgot to mention it -- just mount a pulley at the top of the mast and use a rope to raise / lower the wire antennas. Much easier than trying to un-telescope a mast to get things down.
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