160M Inverted L vs Base loaded 43FT Vertical

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by W5ZZ, Dec 13, 2019.

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  1. W5ZZ

    W5ZZ Ham Member QRZ Page

    Hello guys,

    Want to upgrade my 160m reduced length sloper with a better antenna for a top band.
    I been thinking about Inverted L or a base loaded 43 ft Vertical.
    Which antenna in your opinion will perform better for a long range DX ?

  2. W1VT

    W1VT Ham Member QRZ Page

    Tom calculates the voltages can easily be excessive with a 43' base loaded vertical.

    I have 134 countries with a 36' high Inverted L. Wider bandwith and less loss with the top loading wire than base loading.
    Last edited: Dec 13, 2019
    K8AI, K2XT, W5ZZ and 3 others like this.
  3. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

    You're going to have to use radials for either one of them, so I would definitely use a 1/4 or 3/8 wave inverted for 160. As long as you could at least 30 to 40 foot of it vertical, the more the better.
    N1LOU, W5ZZ, KU3X and 1 other person like this.
  4. AK5B

    AK5B Ham Member QRZ Page

    Like the first two responses I'd add wire to the top of the 43-footer and install plenty of radials (even short ones) as well as a good remote tuner at the base. What I'd do as well if I had the proper space for something like that...
    W5ZZ and KU3X like this.
  5. WA8OLN

    WA8OLN Ham Member QRZ Page

    Inverted " L "
    W5ZZ, AK5B, AI3V and 2 others like this.
  6. N8CMQ

    N8CMQ XML Subscriber QRZ Page

    I wasn't able to get an inverted L, so I did a sloping vertical to the top of a nearby tree.
    It does very well, and I am using over 140 ground radials 30 feet long.
    The nice part is, it has good bandwidth, and the pattern is supposedly near a true vertical pattern.
    W5ZZ and AK5B like this.
  7. WA7ARK

    WA7ARK Ham Member QRZ Page

    When building a 160m Inverted-L, think about all the things you can vary:

    H: Height of radials (ft)
    L: Length of RG8X coax (ft)
    N: Number of Radials
    V: Length of Vertical Part (ft)
    X: Length of Horizontal wire (ft)
    Y: Length of Radials (ft)

    I have created a parametric model of an Inv-L antenna which finds combinations of the variables listed above that makes a coax-feed antenna that has a low Swr50 at a given frequency.

    For example, if I specify that H=1ft, L=75ft, N=8, V=40ft, and then I solve for X and Y, my model shows that the following Swr50, R, and jX plots when X=132ft and Y=20ft:


    With a tuner at the station end of the coax, this should be quite usable from 1.8 to about 1.91MHz. Notice the ratio of the radial length to the total wire (Vvert+ Xhorizontal) length. With eight radials, this is the magic ratio. That ratio changes with more or less radials. I have previously written about these ratios, here.

    Let me know if you would like me to work up some other scenarios.
    WB5YUZ, W5ZZ, W1VT and 1 other person like this.
  8. W5ZZ

    W5ZZ Ham Member QRZ Page

    Thanks friends,

    Inverted L sounds like a winner!
    Ordered 46 ft fiberglass mast from DX Engineering.
    So, vertical part of the Inverted L will be approximately 45ft.
    Instead of the "normal" radials, I am thinking about building an K2AV`s FCP .
  9. K8JD

    K8JD Ham Member QRZ Page

    My Humble Opinion
    Inv L for 160 has to be 130 ft long for the low end (DX ?) .
    Everyone seems to forget the inv L is just a vertical with the top half (or more) bent over !, In a QW ant, the most of the radiation comes from the high current part of the wire and that starts at the feedpoint and tapers off toward the far end.
    I consider a 43 Ft vertical to be optimum for 20 M (5/8 wave), maybe good as a nearly QW vert for 60 M BUT, NOT the best for 80 or 160 , at all !!
    I have used a Halfwave Dipole here for many years and have no trouble working Coast-to-Coast with it in the winter months with just 100 W. I have heard European signals but there is usually a pile up of the 2 kW guys calling them.
    No radials is the best I can do and took down my vertical ant. I deploy the antennas in trees behind the house and just too many surface tree roots to gat any radials down, and low, elevated ones, would get snagged by deer running thur the woods.
    Last edited: Dec 15, 2019
    K0UO likes this.
  10. W9XMT

    W9XMT Ham Member QRZ Page

    For some insight based on a previous study of mine, below is a NEC4.2 analysis of a ~self-resonant inverted L for 160 meters, using an FCP.

    W5ZZ likes this.

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