End Fed Wire - 40m high swr suggestions

Discussion in 'Ham Radio Discussions' started by KC2IEB, Sep 24, 2020.

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  1. AF2Z

    AF2Z Ham Member QRZ Page

    You might want to try a dedicated receive-only antenna. I use a small loop, mounted on a pvc pole at ground level, located well away from my and neighbors' houses. The signal levels on the loop are less than with my wire antennas but so is the noise; sometimes (not always) the signal-to-noise ratio is noticeably better on the loop. I use a LZ1AQ preamp, mounted on the loop pole. If you check the LZ1AQ site you'll find lots of details. This preamp is quite robust & fairly cheap. There are a number of other receive loop systems available; some are pretty expensive.

    With a receive-only antenna you might need to use some T/R switching. My rig has a separate receive antenna port. Also, no RF protection is required with my arrangement (I checked the signal levels carefully on all bands while transmitting up to my maximum 100 watts output). So, it was pretty simple to set up.
     
    Last edited: Sep 28, 2020
    KA4DPO likes this.
  2. W7IMM

    W7IMM Ham Member QRZ Page

    I would tend to disagree. A "dipole" antenna can be fed at the center, "off" center, or at the end. An all cases, it's still a dipole.

    I'll also add that if you do actually feed a half-wave antenna at the end, there's other considerations due to the high impedance and resultant high voltage at the "feedpoint.

    Radiation pattern won't be exactly like a dipole unless the coupler is right at the physical end of the antenna and there's a rather extensive ground system underneath.

    DO NOT use only a ground rod. There needs to be at least as much wire on the ground as there is in the air. AND more is better!

    My end fed antenna is 300ft long, 200 ft between 2 trees about 30-40 feat in the air and at the other end it makes a 90 degree bend and runs for another 100ft.

    I have 5 --135ft "radials" on the ground made from RG-59 coaxial cable. My "Coupler" was an SGC SG-235 auto coupler that I have had for 23 years. I recently replaced it with an MFJ-998RT

    It works great from 160-10 meters up to 1200w (although on 10, 15 or 17) it's not as good as a ground plane or vertical.
     
    Last edited: Sep 28, 2020
    KA4DPO likes this.

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