Making a box section mast telescopic

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by M0JTL, Mar 31, 2021.

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  1. M0JTL

    M0JTL Ham Member QRZ Page

    Hi all,
    I want to build myself an antenna mast for my garden here in the UK, however I am wondering how I would make it telescopic so once the 2nd section raises fully then the top section raises up to maximum height, I have seen some that both sections raise at the same time, however unless I have to I don't really want to do this, unless it's easier and cheaper to make of course.

    As the mast is only going to be a maximum of 10 meters (33 Feet) tall, I want to have it as low as possible when completely lowered to comply with planning regulations.

    Does anyone have or know where I can find plans on how to do this?
     
  2. AK5B

    AK5B Ham Member QRZ Page

    1) Order concentric aluminum tubing with a 0.058" wall thickness. You'll need at least 6-7 six-foot long sections for a 33' mast depending on how much overlap you use. Shop around for suppliers in the U.K but check out Texas Towers and DX Engineering here in the States to get an idea of what you need, cost, etc.

    2) Once you have the tubing, drill holes all the way through each tube near the top so you can run a bolt or lynch-pin through to hold in place. Alternatively, you could use Jubilee clamps to accomplish the same thing.

    3) Figure out how much guying you'll need and lay it out, ready to go .

    4) Nest all the tubing together and start raising and guying as you go along. A helper or two would be best, but it can be done solo if well-planned. Once each section is extended, slip in the bolt or tighten the Jubilee clamp to hold it snugly.
    Repeat this until complete. Stand back and admire your new mast!

    73,

    Jeff
     
  3. RW4HFN

    RW4HFN Ham Member QRZ Page

  4. M0JTL

    M0JTL Ham Member QRZ Page

    Hi Jeff
    Thank you for your reply

    Maybe I didn't explain myself properly, I wish to make the main mast out of square box section then have the last section tubing either 1.75" or 2 inch thick tubing, I want to be able to raise and lower it by means of a winch system, I would like the 2nd section to raise first out of the 1st section when turning the winch then once that section has reached maximum height the top section will then start to rise until full height has been reached, I am unsure how I can do this and would like some advice or plans on how I can achieve this.

    The first section of the mast, which will also tilt over, will be connected to a base post (square box section) which will be about 6 feet in length (2 meters) with approximately 1.5 feet ( 0.5 Meters) that will fit into a concreted ground post
     
    AK5B likes this.
  5. AK5B

    AK5B Ham Member QRZ Page

    OK, Ian; Sorry for my misunderstanding of what you wanted to do. Looks like RW4HFN nailed it! Ambitious project but very cool once completed.

    Ron, NI7J, did something similar at his Arizona HOA QTH; dug a 10' ~ hole so his 10m tall telescoping tubular mast with a pair of Scorpions (in a remotely-tuned multiband dipole configuration) could be fully lowered to ground level when not in use.

    Good luck on everything and feel free to post us pix for us to drool over later on.:)

    73,

    Jeff
     
    RW4HFN likes this.
  6. VE7BPB

    VE7BPB Ham Member QRZ Page

    Ian, you are trying to do something that is unnecessarily complicated.

    Every telescoping mast, and every mobile crane for that matter, extends all of the sections simultaneously. This is the easiest and cheapest way to do it. There is no performance disadvantage to doing it this way. All it requires is a winch, some appropriate pulleys, and steel cable.

    If you really must raise each section sequentially I suggest you start saving up your pennies, because hydraulics are not cheap. Or easy.

    regards, Roy
     

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