EFHW antenna update

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by G8GYW, Dec 31, 2019.

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  1. G8GYW

    G8GYW Ham Member QRZ Page

    What transmit power? I only have 100 watts at the moment. I have heard Japan but they can't hear me.
     
  2. K5EMG

    K5EMG XML Subscriber QRZ Page

    100 watts, it's all what my Icom IC-7300 can do.
     
  3. K5EMG

    K5EMG XML Subscriber QRZ Page

    That's my home and antenna installation, I have power lines in the upper and left part of the picture (North and West of my home), so I'm limited in extending the wired.
     

    Attached Files:

  4. G8GYW

    G8GYW Ham Member QRZ Page

    Interesting, thanks. I haven't tried data modes yet, I prefer voice ...
     
  5. K5EMG

    K5EMG XML Subscriber QRZ Page

    I prefer voice too, but since we don't have the best conditions and I don't have a amplifier/great antenna combo, with data at least I can try to measure my equipment (distance, quality of signal and such) and modify the components to better performance.
     
  6. G8GYW

    G8GYW Ham Member QRZ Page

    Fair point. I've had a 5/9 report with 100W SSB from 3,000km so I reckon with a bit more height and good propagation I will reach the States ...
     
  7. K5EMG

    K5EMG XML Subscriber QRZ Page

    This is the balun I've use. It's made from common electrical wire (14 AWG) and two 240-43 ferrite cores for ample power handing (I used a Chamaleon CHA II antenna but it over heated in a few minutes of using FT8 and the SWR went to the roof) my antenna is connected to my tuner using a 50 feet RG8X cable with the outer braiding as counterpoise, together with several counterpoise cables on my roof, and my shack entry I have a ground rod and the coax is braid is connected to it, after that a single ferrite 240-43 core cmc to isolated noise and keep RFI outside.
     

    Attached Files:

  8. AI3V

    AI3V Ham Member QRZ Page

    That your vswr dosn't approach infinity at the anti-resonant frequencys is telling you how inefficient your antenna is.

    The vswr at resonance tells you nothing!
    Rege
     
  9. PA1ZP

    PA1ZP Ham Member QRZ Page

    Hi G8GYW

    If I look purely to the wireantenna istself, the most radiation is comming from the part of the 10 mtrs wire in front of the 110 uH inductor.
    You also must know that conditions are realy bad last year for DX.
    So in theory it would be best to place the antenna fed from the back of the garden, BUT it could be that you will get a lot of noise on RX in doing this.
    A better idea would be trying to get the end of the antenna in the garden up higher.

    If you want to make larger DX you would be best of on 20 mtr or 17 mtr band at the moment.
    If you have an old CB half wave vertical, you could rebuild it as a 1/4 wave GP for 20 mtrs.
    Or look at the antennas of DX-commander that can be used as a multiband vertical from 40-10.
    There are a lot of video's on you tube to get an idea of Callums antennas.
    If you build one for 20-15-10 in this way it would be about 5.3 mtrs high.

    My experiences with monoband GP on 10-80mtrs is that these antennas are way better in DX as a low placed horizontally polarised antenna.
    Also knowledge of propagation is very handy to improve your DX possibilities.

    73 Jos
     
  10. G8GYW

    G8GYW Ham Member QRZ Page

    I refer you to the contacts made on the map I posted earlier. I'd say it's pretty efficient given its height above ground.
     

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