W5QJR antenna

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This topic contains 3 replies, has 3 voices, and was last updated by  om0aao 7 months, 2 weeks ago.

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  • #18800 Reply

    om0aao
    Keymaster

    Someone tried the W5QJR vertical antenna? http://rfanat.ru/s8/w5qjr2.htm

    if yes, with what results?

    #18940 Reply

    OM800AB
    Participant

    I did not try the W5QJR antenna. I read the article about this antenna and I got the impression, that the author praises a broken vertical, as the optimal antenna for the bands 40, 80, a 160 m. It's such an alibi description of an antenna. The author did not compare this antenna at all with the second antenna, for example dipole. I have good experience with a dipole. I use it in the form of Inverted Vee, the oblique dipole is also good, or more dipoles per power supply, for multi-band operation. I recommend building a vertical antenna at least a quarter-wave with raised quarter-wave radials.

    YOU 73! Fairy, OM3CAQ

    #18957 Reply

    Ron
    Participant

    The antenna works, but optimally it is only a single-band antenna, of which coaxial is a component, which serves as an impedance transformer.

    Determination of this antenna, your wrecker, or an oblique beam from the mast.

    The disadvantage is, that if used stretched at the house, or next to the wall of a bigger house, this antenna radiates into the house and there is also interference in it. Tuning the antenna is not a big problem, but it is very narrow-banded, out of tuning range, the transformation element from the coaxial cable itself also appears to be problematic, too high a voltage starts to appear, which can damage the coaxial dielectric.

    The antenna does not have galvanically connected braids for braiding, if there is a large level of interference next to this antenna, this interference also gets out of range, to the device.

    Far better, but more complicated, are antennas such as today very preferred end fed, or its older versions of the so-called. City windom.

    There is a need for a different impedance transformation, the antenna is significantly longer, but it did not depend on the counterweight.

    It's a lot of inspiration.

    W5QJR antenna, The flood is really designed for installation on a mast, not suitable for apartment building.

    In practice, however, it will probably be better, like no antenna.

    #18967 Reply

    om0aao
    Keymaster

    TNX Vilo and Ron,

     

    at the end a powered antenna like endfed will have high efficiency. It's a very walkable antenna (I tested in the previous QTH). But it's good, to be stretched, for example, from a block of flats, where “stop” against the country. I had it stretched out in the open space and VFka traveled all the way to the facility.

    According to the simulation, it seems, that the maximum current at W5QJR is in the base of the antenna. Simulation with 8x radial in the heel, average conductivity of the earth. It should be a vertical antenna, thus, that part of the antenna is critical to operation. Dimensions should be an advantage, direct power supply by coaxial cable and absence of any loss element in the antenna circuit. It quite resembles inv.L, but where the impedance ratios are different (equally high inv.L has a much lower impedance at the heel). The files are attached.

    According to the possibilities and weather, I would build it and compare it with the used antennas.

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