I have been reading the Basic Antennas and

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KD9DOG, Jun 26, 2021.

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  1. WA7ARK

    WA7ARK Ham Member QRZ Page

    Yes, I appreciate that, but I wanted to show that a straight "unadorned" center-fed 40m dipole does not automatically create a useful 15m antenna without a lot of help!
     
  2. WA7ARK

    WA7ARK Ham Member QRZ Page

  3. KD9DOG

    KD9DOG Ham Member QRZ Page

    RW4HN, I do not no how to read the Data you sent, also you say to connect each capacitor in each half How do I do that? Must go read some more
    One other important item I plan on going full Legal limit>
    Regards
     
  4. KD9DOG

    KD9DOG Ham Member QRZ Page

    Mike about the torid I am planning on running full legal limit, is there a progrm to help with installing a Torid?
     
  5. WA7ARK

    WA7ARK Ham Member QRZ Page

  6. KO4CQ

    KO4CQ Ham Member QRZ Page

    While everyone is extolling their favorite antenna, I might as well jump in too. Just about the simplest multi-band (without a tuner) is the ZS6BKW. It is easy to construct, only requires two supports at each end, and works well without a tuner, but you may want to use your rig's internal tuner. The flat top version requires about 92 feet, but my installation has one end hanging down about 10' and it works fine. As they say, "But Wait!" There is shortened version that only requires about 47 feet end to end. The remaining length (about 24 feet) at each end hangs straight down. I have not tried this version, but plan to put one at 90 degrees to my existing antenna.

    Thirty-nine to forty feet of 450 ohm ladder line is connected to the feed point, and a 1:1 balun at the other end connects to 50 ohm coax to the shack. An internet search will return more information about the ZS6BKW than you really want to know.
     
    K9UR likes this.
  7. K8JD

    K8JD Ham Member QRZ Page

    I have seen short wires adeed , dangling down near the end of a 40 M ant make it work on 21 MHz, but using the third harmonic on an 80 M dipole was just too far off to work on 30 M (at least for me)/
     
  8. RW4HFN

    RW4HFN Ham Member QRZ Page

    . maa (in zip.) - the file of the MMana antenna modeler. You can download it, for example, from here.

    http://gal-ana.de/basicmm/en/

    The 255 pF capacitor or 2 x 510pF capacitors are connected in SERIES to the source (around 100 - 110 Ohm). The difference of the capacitive resistance at 40 and 15 m leads resonances to the middle of the bands. A cable transformer (1\4 or 3\4 lambda, made of a 75-ohm cable) makes about 50 ohms out of 100-110 ohms.
     

    Attached Files:

    Last edited: Jun 29, 2021
  9. N0NC

    N0NC Premium Subscriber QRZ Page

    James;
    I've had very good luck with my HF9V. The only band that jumps around a lot in the wind is 15 meters. If other bands (80 and 40 especially) are jumping aound in the wind, check for something loose, or as was said above, or a damaged capcitor. I'm at 200+ (mostly cw) DXCC on LOTW with mine. Ground mounted with about 20 33 ft. radials. Have had several over the years, good antenna, but takes some work to get it set up, and of course regular maintenance. You'll want some thing else for 80 though, mine is about 35khz wide on the lower end of 80 and maybe 45 on the high end of 75, and about 200 khz on 40 meters.

    I used to have a 260 ft center fed dipole for the low bands, but since I moved into a duplex in town, I have no trees so a ground mounted vertical is all I've got now.

    Good Luck with the butternut.

    73, Chuck
    N0NC
     
  10. KD9DOG

    KD9DOG Ham Member QRZ Page

    I went out and tuned the HV9 and I can use almost the entire band except 12m. Any way I have been scouring the internet and books I have and I cannot find out how to go from my coax to and EFHW wire with out a transformer or tuner, the only thing I come up with is I attach the center core of the coax to the antenna and the braid to a counterpoise, still the articles I read still had a tuner coil or transformer .
     
  11. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    An EFHW (end-fed, half-wave) always requires a transformer.

    To feed with coax, usually a 49:1 Unun, which can be homebrewed but there are several manufacturers who sell them pre-made in weatherproof housings. The "myantenna" product is very good and available at various power levels.
     
  12. KD9DOG

    KD9DOG Ham Member QRZ Page

    The EFHV type antenna is more than I want to get involved with and my wife is not seeing any humor so I am going to give up this wild idea save money and keep the MRS happy.
    Thank you all and have a GREAT 4th of JULY
     
  13. N0NC

    N0NC Premium Subscriber QRZ Page

    It sounds like you've got the HF9V mostly working. Yeah 12 and 17 meters are very touchy to adjust, More of once you get it close, you just kind of massage the coils to zero it in. I use a ruuning clip lead to short out the bottom 4 or so turns of the 80 meter coil to move from approx. 3530 khz up to 3970 khz when I want ot use it on 75 SSB. A vertical is not a very good antenna for close in low band work. Checking into the local Iowa traffic net, I run the AL-80B so the net control station can hear me. If you do a lot of 40 or 75 meter local work, you might think about a fan dipole for 40 and 75. I've guess I'm a heritic, but most of the dipoles I have put up over the years were fed with coax and no balun for a single band, or multiband fed with ladder line or twin lead and a manual tuner.

    When I lived on an acerage, i had a low 260 foot dipole fed with twinlead that I used for 160, 80,and 40, and the vertical for the higher bands. Worked a lot of DX with those antennas. Even worked Russia on 160 meters (the other guy must have had a monster antenna). If you don't have tall trees (or towers), most any antenna you can put up is going to be a compromise. Now that I live in a Townhouse (actually a duplex) with no trees at all, the vertical is all the landlord would agree to. Ground mounted with buried radials, but works well. Of course being in the city, my noise floor is a lot higher than it was out in the country.

    Put up what you can, and have fun. Thats what its all about.

    73, Chuck
    N0NC
     
  14. K9ARI

    K9ARI Ham Member QRZ Page

    Understandable :)
    This is the no-brainer, permanently installed, high power, multi-band, no tuner, EFHW option (for reference, if you change your mind):
    https://myantennas.com/wp/product-category/antennas/efhw-multi-band/

    I just made a portable low power EFHW for under $30 from a kit from QRP guys and a couple wires from a cat 5 cable I untwisted. Lots of work. BUT I can verify that it works on 40, 20, 15 and 10 without a tuner and "seems" to have higher gain than the dipole. Plus end feeding is convenient. It's about 60 feet long. If you have enough room for 80 (130 feet) you supposedly get even more bands.

    The real beauty is that 24 gauge wire disappears up in the air.
     
  15. K7OFG

    K7OFG Ham Member QRZ Page

    The center fed die pole cut to the frequency you desire is the way to go but it only gives you one band and usually not all of it. I have been using an MFJ-1984MP for my portable rig without a tuner and do 40 and 20 with very low SWR. There is a good write up on the EFHW in another question on this same forum section with a link to how to build your own.
    I do like the EFHW antennas.
     

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