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.

ASTROPLANE best vertical antenna ever?

Discussion in 'CB Antennas' started by nosepc, Oct 6, 2013.

  1. w9cll

    w9cll
    Expand Collapse
    W9WDX Amateur Radio Club Member

    Joined:
    Jan 19, 2013
    Messages:
    2,866
    Likes Received:
    1,481
    Everyone says 59 copy even if you are barely readable. It's amazing how many times I hear someone say they are 59 and keep asking them to repeat what they said.


     
    Needle Bender likes this.

  2. HomerBB

    HomerBB
    Expand Collapse
    Sr. Member

    Joined:
    Jan 4, 2009
    Messages:
    2,863
    Likes Received:
    615
    I'm not 5-9. I'm 5-7, but what does my height have to do with anything..?
     
  3. Needle Bender

    Needle Bender
    Expand Collapse
    ...he thinks it's funny that I stepped in it

    Joined:
    May 15, 2010
    Messages:
    1,401
    Likes Received:
    282
    I loved your post, Homer, but have to disagree.

    We've talked via DX conditions, and though it's been a couple years since our contact on Lsb-38, I recall you were 5 OVER. 9.

    [​IMG]
     
    HomerBB likes this.
  4. HomerBB

    HomerBB
    Expand Collapse
    Sr. Member

    Joined:
    Jan 4, 2009
    Messages:
    2,863
    Likes Received:
    615
    I was standing on a bucket that day.
     
    tecnicoloco and Needle Bender like this.
  5. PD0G

    PD0G
    Expand Collapse
    New Member

    Joined:
    Jan 17, 2017
    Messages:
    3
    Likes Received:
    4
    JAF0 and 2RT307 like this.
  6. Riverman71

    Riverman71
    Expand Collapse
    Well-Known Member

    Joined:
    Nov 12, 2013
    Messages:
    849
    Likes Received:
    270
  7. HomerBB

    HomerBB
    Expand Collapse
    Sr. Member

    Joined:
    Jan 4, 2009
    Messages:
    2,863
    Likes Received:
    615
    Awesome!
     
  8. 2RT307

    2RT307
    Expand Collapse
    Sr. Member

    Joined:
    Nov 22, 2011
    Messages:
    2,177
    Likes Received:
    650
    That's pretty darned cool. Now you need to make a PDL II for 70cm, too. :)

    73,
    Brett
     
  9. The DB

    The DB
    Expand Collapse
    Sr. Member

    Joined:
    Aug 14, 2011
    Messages:
    1,586
    Likes Received:
    673
    Putting a set of radials below the basket area? That thought hadn't occurred to me... Lets play...

    Doing some initial modeling, I got a some amount of additional gain by adding radials and putting them 51.5 inches below the ring (dimension for CB sized antenna, not the 70 cm version with radials shown above). This distance was the distance that gave me the best results...

    [​IMG]

    Now I haven't played with this model much, so I am not sure if the benefit of adding radials has to do with the mast length (that goes all the way to the earth below the antenna in the radials model). I have not yet looked at this antenna with other mast lengths or antenna heights. However, for those who would have issues isolating a mast at a given location for optimal performance, adding a set of radials at a specific location *might* be an alternate solution...

    Unfortunately I don't have time to play with this idea at the moment...


    The DB
     
  10. PD0G

    PD0G
    Expand Collapse
    New Member

    Joined:
    Jan 17, 2017
    Messages:
    3
    Likes Received:
    4
    Thank you .... Have the astroplane signed in Mmana.
    21586783_456498904744291_5871971967640675690_o.png
     
    JAF0 likes this.
  11. The DB

    The DB
    Expand Collapse
    Sr. Member

    Joined:
    Aug 14, 2011
    Messages:
    1,586
    Likes Received:
    673
    A few days ago I was talking to bob85 about the Vector antenna and the ability to steer where the signal goes in freespace models. The Astroplane patent also refers to this concept, so I am looking to put that to the test.

    So according to the patent, changing the diameter of the ring, and the adjusting the elements that support the ring to compensate, you can change the "take off angle" of this antenna. In reality, the "take off angle" will not change as in the presence of an earth the earth and the height of the antenna above said earth are what actually controls said "take off angle". However, is it possible to control the antenna's angle of radiation before the earth is in play? The quote above from the patent suggests that this is a possibility.

    To start with, we model the Astroplane antenna in freespace.

    [​IMG]

    Here we can see that peak gain is actually at a downward angle. When it comes to local communications, this would be a benefit as it is pushing its signal down towards the earth, instead of straight out or angled upwards like many other antennas.

    In one model I added five inches to the ring radius, and in another I made the radius 5 inches shorter. I did some modeling of ring sizes within this range as well, but those are not shown here. Here is a comparison of the three models.

    [​IMG]

    The sr model (in green) used the smaller ring, and the lr model (in blue) used the larger ring.

    As we can see, the results are very similar, even with such a large change to the ring diameter. This likely is because the ring does not carry much current, and includes a current null as well. Because of this it takes a larger change to to this area of the antenna to affect the radiation pattern of the antenna than if a current node or higher current was present on said portion of the antenna.

    I was able to achieve said RF steering with these changes, however, as we see their isn't much of a difference. Adding five inches to the radius was able to steer peak gain up by one degree, and removing five inches from the radius was able to steer peak gain down by a degree. On its own I would say that such a large change to the antennas dimensions for such a small change when it comes to the radiation pattern on makes this, as far as rf steering goes, a pointless endeavor. However, that is not all that is in effect in these models.

    The larger ring, in addition to steering rf up a degree, also increased the antenna's peak gain. This change in gain was enough that despite the angle of peak gain being further away from a desired angle pointing further down for local contacts, their is actually more gain pointed at said lower angles.

    That was definitely not what I expected.

    This is a preliminary result, however, it is suggesting that using a larger ring, and shortening the elements that connect said ring to the antenna to compensate, actually increases both the local and DX potential of this antenna.

    Anyone want to try this out with a real world test?


    The DB
     
  12. Marconi

    Marconi
    Expand Collapse
    Usually if I can hear em' I can talk to em'.

    Joined:
    Oct 23, 2005
    Messages:
    5,442
    Likes Received:
    585
    DB, what does this FS antenna look like?

    How did you handle the mast inside the antenna for this Free Space model that generated this pattern?
     
  13. The DB

    The DB
    Expand Collapse
    Sr. Member

    Joined:
    Aug 14, 2011
    Messages:
    1,586
    Likes Received:
    673
    Its the same model I used before, the one with the optimal length isolated mast. I forget the dimensions offhand and am out camping at the moment, so if you need specific dimensions let me know and I'll get them to you when I get back home.


    The DB
     
  14. Marconi

    Marconi
    Expand Collapse
    Usually if I can hear em' I can talk to em'.

    Joined:
    Oct 23, 2005
    Messages:
    5,442
    Likes Received:
    585
    DB, my Old Top One model shows what I consider a more traditional Free Space pattern and I can't explain the difference from your model.

    upload_2017-10-14_2-0-45.png

    Here is the A/P pattern in the Patent 3.587.109 which shows a similar tilt for the lobes. Neither pattern resembles your model.

    upload_2017-10-14_2-57-49.png

    This is not to suggest that a modified antenna of this type can't be made to show different results.
     
    #239 Marconi, Oct 14, 2017
    Last edited: Oct 14, 2017
  15. JAF0

    JAF0
    Expand Collapse
    New Member

    Joined:
    Oct 2, 2017
    Messages:
    24
    Likes Received:
    5
    Hey where are you camping and did you take a radio & antenna with you?
     

Share This Page