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Comparing Elevated 1/4w Vertical vs. Link Dipole with WSPR

Discussion in 'Amateur Radio News' started by K5ACL, Nov 15, 2017.

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  1. NK9Y

    NK9Y Subscriber QRZ Page

    In the 80's, each winter for several years, I compared a quarter wave vert on top band, gnd mounted, with over a hundred radials buried. The other was the same antenna, only raised feedpoint, single counterpoise. Regularly noticed stronger reports on the much simpler antenna. Also noticed, if the counterpoise was angled downward a touch, the feed point would approach 50 ohms. Good enough for me, and plan to try it again soon.
     
  2. W1YW

    W1YW Ham Member QRZ Page

    Not relevant to my points.

    Your gain differences are caused by launch angle differentials.

    Carefully designed grounded systems outperform raised, sparse counterpoises. Having 100 radials doesn't mean you have accommodated ground losses, for example. The mirror image assumption is still not appropriate: the ground plane is not sparse close in, but is still truncated..

    For most hams, raised radials are advantageous, no doubt. For me, I knew how to control ground losses and enhance the (true)surface wave. My launch angle was very low. No reason to use raised 'radials' as the launch angle would go up 5-10 degrees here.

    73
    Chip W1YW
     
  3. NK9Y

    NK9Y Subscriber QRZ Page

    Yes, I get that. Antennas are my hobby, not my business. And I am not trying to diminish your accomplishments, as they are very well documented. That being said, a dxpedition to VK9, calling CQ, an hour before my grayline peak could not hear my 100 watts into my non accommodated ground loss system after numerous calls. The simple, and much cheaper elevated counterpoise got in the log on the first call. My comment about the wet noodle with the can of peas was intended as a joke. I hope you understand that.
     
    W1YW likes this.
  4. W4HM

    W4HM Ham Member QRZ Page

    Chip be careful you might confuse some with facts about how antennas really work. :D
     
    Last edited: Nov 20, 2017
  5. W1YW

    W1YW Ham Member QRZ Page

    You know, I came out too strong. My intent was to convey the facts; it gave the impression I don't respect the practical efforts and the results obtained, and that is unfortunate.

    You guys are doing what's right for you, and having fun. That includes Chet. Keep it up.

    73
    Chip W1YW
     
    NK9Y likes this.
  6. NK9Y

    NK9Y Subscriber QRZ Page

    I forgive your backhanded arrogance.
     
  7. W4HM

    W4HM Ham Member QRZ Page

    You can't raise the feed point of a 160 meter 1/4 wave inverted L/vertical high enough to overcome RF ground current losses. I always had to put at least 60 1/4 wave radials on the ground to overcome most of the RF ground losses.

    I did find that the length of the ground radials didn't have to be any longer than the antenna was tall. So if my 160 meter 1/4 wave inverted L had a 60 foot vertical section then 60 foot long radials would be passable.

    In experiments many decades ago by the FCC, they discovered that laying down more than 60 1/4 wave radials they started seeing diminishing returns. But then in their infinite wisdom they decided to say that 120 radials on the ground was going to be their golden rule of thumb for AM broadcast band verticals.

    There is no magical free lunch with antennas.

    BTW I've always laid my wire radials on the ground surface and then tacked them down with home made metal staples. By the time the staples rust away the grass has grown over the radials.
     
    VK6APZ likes this.
  8. NK9Y

    NK9Y Subscriber QRZ Page

    When I tried the system you have described, it was over ancient peat bog soil. (good farm land) Four ground rods about 15 feet long, which is to say two 8 footers, bonded together, times four. They were connected to the screen of over 100 radials, 60 feet sounds about right, I really don't remember. They were 3 or 4 inches below surface. We have trouble with frost heaving this far north. Do remember the feedpoint impedance to be somewhere around 37 ohms.

    The next game was same thing with feedpoint at about 20 feet, the single counterpoise dropped to about 8 feet at the end. Feedpoint was near 50 ohms. All I know is it worked, and I usually kept the legal limit amp off line, just for kicks.

    Am eager to put up 130 foot of aluminum, on top of a 42 vacant electric pole now though. And there WILL be a counterpoise under it. Only problem will be finding enough room to put up the half mile long beverage again. Only 17 acres on this place.
     
  9. W1YW

    W1YW Ham Member QRZ Page

    Again, an absense of the facts. Please look up the word 'arrogance'. You shouldn't confuse a 'front' of knowledge with the reality.

    No forgiveness requested nor accepted. Nor relevant as per your specious premise.

    Please listen to Tom and you may learn something. Obviously it didn't work for you when I tried.

    73
    Chip W1YW
     
  10. NK9Y

    NK9Y Subscriber QRZ Page

    No one will ever take away my enjoyment of playing with antennas. If my results have been fact/science based, or just simple luck, it still has been a fun ride.

    This thread has gotten away from its original intent, so this will be my last post on the subject. Not really the hill I care to die on.

    For those following, who are now curious about the inverted L antenna, check up on the "coaxial inverted L". It has much greater bandwidth over the traditional design.

    73 to all, and fear no "techno-bullies"

    NK9Y
     

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