hf 40 meter 3 ele yagi

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by 9M6BZ, Jan 17, 2013.

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  1. 9M6BZ

    9M6BZ Ham Member

    Hi there you guru of antenna builders.I would appreciate if you cold help me with some info and specs on my 2013 project . Trying to built meself a 40 meter yagi ( 3 ele) what i need would be the specs.. like the ele length,the ele tube size, tge ele spacing and what sort of antenna matching do i need.. I have a very big yard at my home QTH I also have a tower ie 60 feet high and i would to operate say 1 kw power from it. thanks guys. De 9M6BZ
     
  2. KO6WB

    KO6WB Premium Subscriber

    There's this one which seems a bit unusual but it'll work; http://www.hamuniverse.com/na4lquagibeam.html.
    Then there's the one made by M2 and this gives you all the details on how to make it yourself; http://www.m2inc.com/pdf_manuals/40M3L.pdf. Good luck doing that.
    On this site there is a calculator that will give you the dimensions for a four element beam measurements. Just enter the frequency in MHz and have it calculate; http://www.packetradio.com/antennas.htm. Just ingnore the second director and it'll be the proper dimensions for a three element 40 meter beam. This is really a handful to take on.
    There are other variations that'll work as well.
    Here's a loaded Moxon; http://www.moxonantennaproject.com/IK0GDH/IK0GDH.htm.
    Then there is a switchable dipole array that goes up quick and doesn't need a rotator; http://www.oe5.oevsv.at/opencms/technik/antennen_dl/sloperen.pdf. You can make the dipoles full sized and you can add more of them. The ARRL Antenna Book has this same antenna in their publication except it uses 5 dipoles and they are full sized. Perfect for a tower installation.
    Just more thoughts.
    BTW you can take any HF mono-band beam of known dimensions and scale it to work on any frequency you want. Just figure out the multiplier ratio of the antenna and then apply that to your end results. Example: You find a three element beam for 20 meters that is centered on 14.2MHz but you want to make an antenna for 40 meters centered on 7.05MHz. Take all the dimensions of the 20 meter beam and multiply them by 2.014. Instant antenna dimensions just that easy.
    Hope this helps
    73
    Gary
     
  3. K4SAV

    K4SAV Ham Member

    The links Gary gave you are not for full size Yagis. Not many people make full size 40 meter Yagis. M2 has one and Telerex had one. Here is information on the 40M3FS.
    http://www.m2inc.com/pdf_manuals/40M3FS.pdf

    Building this is a major task and a major expense. At 180 lbs and elements lengths close to 65 ft on a 47.5 ft 3.5 inch diameter boom, it takes a big tower and rotator to handle it. It's not a job most people would attempt.

    Price for this antenna is over $4000. I'm not sure what it would cost you to build it, but it won't be cheap.

    Jerry, K4SAV

    edit: ON4UN's Low Band DXing Book has complete design plans for a 40 meter 3 element Yagi.
    The ARRL Antenna Book also has some limited information on a 40 meter 3 element design.
     
    Last edited: Jan 17, 2013
  4. W9GB

    W9GB Ham Member

    From your web page, it is clear that you are experienced in dealing with large antenna arrays.

    A 40-meter 3-element Yagi antenna DIY build amplifies the issues to address -- due to significant size, weight, and costs for such an antenna as well as tower and rotator system.
    For 40-meters, you are doubling the wavelength (elements) from 20-meter antennas. A 3" to 3-1/2" aluminum boom would be expected.

    STEPP-IR offers their DB-18 series of 3-element antennas for 40 to 6 meters (lighter in weight),
    but costs $3,000 to $3,500 USD.

    Fixed wire beams for 40 meters have been successfully used, at substantially lower costs.
     
    Last edited: Jan 17, 2013
  5. KO6WB

    KO6WB Premium Subscriber

    The folks at Ultrabeam also have offerings that will do very well. As might imagine their very expensive as well. The first thing that shows up is their new UB-1040. Make you just want to win the lottery that much more.
    You can see what they offer here; http://www.ultrabeam.it/site/index.php?lang=en.
    Not sure but it definitely looks to be full size calculations given here; http://http://www.packetradio.com/antennas.htm. The only thing is the value is in inches. Divide by 12 to get feet.
    Still sorting through their site trying as I may to find their price list.
    Be back in a few
    Okay I think I found one spot listing the UB-1040 but still not sure because they define it differently but it appears to be 5000 Euro's which about 6700 USD. As expensive as that appears to be amateur radio still has a long way to go to catch up to the cost of amateur astronomy.
    73
    Gary
     
    Last edited: Jan 17, 2013
  6. K4SAV

    K4SAV Ham Member

    I don't think you will find that antenna for sale in the US. SteppIR holds the patent in the US. They must have figured it was too expensive to patent it in other countries.
     
  7. KA7NIQ

    KA7NIQ Ham Member

    Why not build a 40 meter Hex Beam :p
     
  8. WA7PRC

    WA7PRC Ham Member

    I have 2 linear loaded elements on 40m that work FB at 22m AGL but would love to have 3 fullsize elements.

    It is worth reading the notes of L.B. Cebik W4RNL (SK) on 40m yagis: http://w4rnl.net46.net/40wb.html.
    Also, many folks on the Tower Talk Email Reflector build and use larger yagis. You might try searching the archives, or ask your question there as well.
     
  9. KC8VWM

    KC8VWM Ham Member

    Too light... Not as much trouble to put up.. where's the heck is the challenge in that?

    Besides, a hex beam wouldn't have the same dramatic effect as 180 lbs. of aluminum, when it comes crashing down from the sky above. :p
     
  10. KO6WB

    KO6WB Premium Subscriber

    You can get them shipped in and they have made a point of alerting US amateurs of their product line. They are more expensive then SteppIR. That withstanding the OP is in Malaysia and I doubt that's a big problem over there. I mean, wow, not three but four elements on 40 and full size to boot. and then even more elements on all the other bands as you go higher up in frequency. One of these days when I win the lottery. I think you have to play the lottery to win it unless you mysteriously were entered in the ones in Nigeria like I was. I'm waiting for my e-mail conformation that my deposit to release the money has been received by my good friend Magomo via Western Union.
    73
    Gary
     
    Last edited: Jan 18, 2013
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