1. You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
    Dismiss Notice

Is the Sirio Gain Master really a good DX vertical ?

Discussion in 'CB Antennas' started by RadioDaze, Oct 2, 2015.

  1. Shockwave

    Shockwave Sr. Member

    Joined:
    Sep 19, 2009
    Messages:
    3,161
    Likes Received:
    1,884
    Many vertical antennas can work well close to the ground. However, once you mount an 11 meter horizontal 5 feet off the ground, you have lost most of the horizontal component and directional characteristics. The close ground reflections force the signal up into the vertical plane.


     
    Marconi and AudioShockwav like this.

  2. Unit 75

    Unit 75 "TRAINMAN"

    Joined:
    Jul 29, 2014
    Messages:
    424
    Likes Received:
    661
    Just for clarification, Are you are referring to a beam antenna mounted horizontally 5 feet off the ground? If so, Why? Because most people I know mount their horizontal orientated antenna higher than just 5 feet. Thanks.
     
  3. Jay Mojave

    Jay Mojave Well-Known Member

    Joined:
    Nov 17, 2015
    Messages:
    156
    Likes Received:
    225
    Hello Shockwave: Is this elevation angle info measured data? Or maybe computer generated data??

    Jay in the Great Mojave Desert
     
    Marconi likes this.
  4. Shockwave

    Shockwave Sr. Member

    Joined:
    Sep 19, 2009
    Messages:
    3,161
    Likes Received:
    1,884
    I'm not sure where this is documented but anytime I've placed a dipole on this band that low to the ground, it was sensitive to signals from more than just the broadside directions and also gained vertical sensitivity at the loss of horizontal signal. On that note, all I have to go on is memory here so if someone has had a similar or different experience, please share.
     
  5. Unit 75

    Unit 75 "TRAINMAN"

    Joined:
    Jul 29, 2014
    Messages:
    424
    Likes Received:
    661
    I found this at the ARRL dot ORG site but it was referring to a horizontal antenna over flat ground
    "The dipole is a straight length of wire (or tubing) into which radio-frequency energy is fed at the center. Because of its simplicity, the dipole may be easily subjected to theoretical performance analyses. Further, the results of proper analyses are well borne out in practice. For these reasons, the half-wave dipole is a convenient performance standard against which other antenna systems can be compared. Because the earth acts as a reflector for HF radio waves, the directive properties of any antenna are modified considerably by the ground underneath it. If a dipole antenna is placed horizontally above the ground, most of the energy radiated downward from the dipole is
    reflected upward. The reflected waves combine with the direct waves (those radiated at angles above the horizontal) in various ways, depending on the height of the antenna, the frequency, and the electrical characteristics of the ground under and around the antenna. At some vertical angles above the horizon, the direct and reflected waves may be exactly in phase—that is, the maximum signal or field strengths of both waves are reached at the same instant at some distant point. In this case the resultant field strength is equal to the sum of the two components. At other vertical angles the two waves may be completely out of phase at some distant point—that is, the fields are maximum at the same instant but the phase directions are opposite. The resultant field strength in this case is the difference between the two. At still other angles the resultant field will have intermediate values. Thus, the effect of the ground is to increase the intensity of radiation at some vertical angles and to decrease it at others. The elevation angles at which the maxima and minima occur depend primarily on the antenna height above ground. (The electrical characteristics of the ground have some slight effect too.)"


    Reference https://www.arrl.org/files/file/antplnr.pdf

    You can scroll down to page 5 under Horizontal Antennas Over Flat Ground
     
  6. Shockwave

    Shockwave Sr. Member

    Joined:
    Sep 19, 2009
    Messages:
    3,161
    Likes Received:
    1,884
    Well that explains why there are so many variables and different results with this. It just depends on where you are talking and how the direct and reflected signals are in alignment (or not) at that location. Thanks for providing additional information on the subject too.
     
    Unit 75 likes this.
  7. Mudfoot

    Mudfoot Elmer

    Joined:
    Jun 17, 2009
    Messages:
    10,130
    Likes Received:
    5,018
    I had an Antron mounted about 3'. It did better than I thought it would.
     
    2NC995 likes this.
  8. Mark Malcomb

    Mark Malcomb Member

    Joined:
    Nov 27, 2019
    Messages:
    48
    Likes Received:
    54
     
  9. Mark Malcomb

    Mark Malcomb Member

    Joined:
    Nov 27, 2019
    Messages:
    48
    Likes Received:
    54
    I'm all Maki bro. Don't know how to navigate this site. I fell dumb. Thanks for response. Buddy I'm lost on posting, or anything. I do have radio probs. dont want to be rude to the site
     
  10. DXman

    DXman Sr. Member

    Joined:
    Apr 5, 2005
    Messages:
    1,546
    Likes Received:
    556
    Good ole Bruno, I have talked with him and his wife Luna several times, she is one funny lady on the radio!!
     
    2NC995 likes this.
  11. L2

    L2 Well-Known Member

    Joined:
    Mar 3, 2018
    Messages:
    131
    Likes Received:
    142
    I have a few friends that use Gainmasters. I can talk the same dx with my Imax.
     
  12. Boat Anchor 63

    Boat Anchor 63 New Member

    Joined:
    Jan 4, 2020
    Messages:
    2
    Likes Received:
    0
    The gain master has beaten alot of 5/8 vertical and people still don't believe how good it is.
    Put it up against a maco 3 element on the vertical side then after it beats it then leave it alone.
     
  13. Shockwave

    Shockwave Sr. Member

    Joined:
    Sep 19, 2009
    Messages:
    3,161
    Likes Received:
    1,884
    The Gain Master has an edge on other 5/8 wave antennas for sure. It works DX well with virtually no RFI. However, if it ever outperforms a 3 element vertical beam, that beam was definitely not working correctly or the test had other, unconsidered variables skewing the results.
     
  14. Supspt454

    Supspt454 Member

    Joined:
    Sep 10, 2012
    Messages:
    56
    Likes Received:
    23
    Great antenna. Only problem is they don’t like Oklahoma wind. I came home from work one day and mine was broken at the lower shaft. Coax was all twisted up and damaged before I could get it down. Sad day
     
    Slowmover likes this.

Share This Page

  • About Us

    The WorldwideDX Radio Forum was originally established in 2001. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. We are working every day to make sure our community is the best Radio Hobbyist's site.
  • Like us on Facebook

  • Premium VIP Member

    The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Care to buy us a beer? We'd really appreciate it!

    Donate to us!