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Amateur amateur radio; my vertical antenna

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KN6CSB, Sep 14, 2019.

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  1. KN6CSB

    KN6CSB Ham Member QRZ Page

    I was tweaking the length of my vertical a bit and I realized it looked so beautifully ugly I had to take a picture and show someone.

    That is a scrap piece of 1/8 inch plate of aluminium into which I drilled some holes to add bolts to add radials. I have this radial plate lifted about 4 feet from the ground in an effort to have raised radials.

    The vertical radiator strings down from that tree, I know it's close to it but it's the best I can do for now.

    oh the joys of playing around with building first antennas .. funny enough I haven't built a dipole yet, the hams "first antenna" according to many. I also can turn this into an inverted L, which I will do next to get back on 80meters :)
    AJ5J, WA3GWK, KA0HCP and 2 others like this.
  2. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    Electrons don’t care about how it looks!
    WA8OLN, KN6CSB and AJ5J like this.
  3. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page should start an "ugly antenna" competition.:)
    N0TZU, KN6CSB, AJ5J and 2 others like this.
  4. WA6SW

    WA6SW Ham Member QRZ Page

    Good thing it doesn't rain in So. Cal.
    KN6CSB likes this.
  5. AJ5J

    AJ5J Ham Member QRZ Page

    Gabriel; Indeed you can---and there's something else you can do that is both easy and will continue to delight your team of electrons and all-important photons: add another wire element to the center conductor of your feedline for 20m (presuming that the element going up into your tree is cut for 40m from what I gathered looking at your QRZ page). Add that wire (@16.5' or so) and add a couple/few more elevated 16.5~ radials to your nifty plate and you will then have an elevated two-band fan Marconi that shouldn't require a tuner (which can add a bit of loss into the system). Space the two vertical wires a couple or more inches apart to avoid interaction and make it easier to tune to resonance on each band. (you could add more wires a la M0MCX's DX Commander for more bands but probably not worthwhile with the low sunspot numbers now).

    Once you do this there is still no reason you have to ditch this if you want to turn the whole shebang into an inverted L, either. Just add wire to where your antenna is going to become horizontal (probably around the top of the 33' element) so that it also resonates on the 80m frequency you plan to use the most---then you have a three-band fan inverted L (or parallel Frankentenna or "Square Root" antenna which is what I've seen others call this crazy mixed-up, multiple personality antenna) .

    Done halfway right it will still be kinda ugly but it's performance is very likely to please you---especially in this time of low solar activity. 20, 30, 40 and 80 meters are truly the best bands for dx now and into the next four or five years at least.

    I also really like your ambitious antenna experimentation---something rarely seen in today's new hams! As they say in VK land; "Good on ya, mate!"

    GL DX, too.


  6. KN6CSB

    KN6CSB Ham Member QRZ Page

    Yes I tried that and it worked.. physics is strangely amazing! I want to string up the inverted L but since I am now more interested in better efficiency I am unsure how long the horizontal part should be.. the Vertical part is about 33 feet long, the most i can get the horizontal out due to my other tree is maybe 75 feet.. honestly have to measure since I am just using eye to guess and i can be way off.
  7. AJ5J

    AJ5J Ham Member QRZ Page

    Great; I think that'll work---but KD6RF is the real inverted L guru around here. I seem to recall a total length including the vertical part of 90 feet is good for 80m and higher---perhaps others will correct me if I'm wrong on this soon.

    Got to run now, more later...
  8. AI3V

    AI3V Ham Member QRZ Page

    The inverted l is just a bent 1/4 wavelength Marconi.

    Make the vertical part as high as you can , and adjust the length of the horizontal part to resonate.

    Don't overthink it. :)

    WA8OLN likes this.
  9. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    If you use low-loss coax and a good tuner, I've found it best to make an inverted-L "non-resonant" to avoid the super high feedpoint impedances that can be encountered by resonant lengths when they're 1/2-wave, 1-wave, 1.5-wave etc.

    My 80m/160m inverted L was 165 feet long, and not resonant on either band but quite easy to match with a tuner; using low-loss coax the added line loss from mismatch was very, very small (on the order of <1 dB).

    Mine was 40' vertical, 125' horizontal. Worked quite well, based on comparative reports with other local hams using all sorts of antennas working the same stations.
    KE0EYJ and AJ5J like this.
  10. KN6CSB

    KN6CSB Ham Member QRZ Page

    ah yes thanks for this info, I have been searching for optimum lengths, they seem to be all over the place. I use lmr 400 coax at about a 30 foot run so I think my losses aren't too bad on HF, and will use a tuner with a 4:1 unun is the plan. the unun is optional since I think my tuner can hand up to about 1000 ohms and I have noticed the strange effect of my coax line reducing ohms to the tuner.

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