dipole

Discussion in 'On the Road' started by W5HV, Apr 15, 2021.

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  1. W5HV

    W5HV Ham Member QRZ Page

    Any ideas on the best and easiest wire antenna to use and put up
    when working portable im planning 20 and mabe 40 it has to
    be easy to put up and take down plus perform well thanks for
    any input
     
    YB8FMN likes this.
  2. W7HV

    W7HV Ham Member QRZ Page

    Dipole is certainly good, but you need to support each end, and preferably the middle feed point. Then you need a long feed line. End fed can be a lot easier to string up and you only use a very short feedline. That's what I've typically used. Here's my home-brew QRP 20m end fed with tuner. When packing it up, figure eight the wire around your thumb and pinky. It won't tangle that way.
     

    Attached Files:

    YB8FMN likes this.
  3. KU3X

    KU3X Ham Member QRZ Page

    You can't get too much easier than a simple dipole for portable. No trees to hang one? Go to any big box store and purchase a painter's pole. They are
    cheap. Also get some nylon 1/8" rope. Now you have a simple mast and some rope to hold it up. A dipole is a simple and very efficient antenna.
    You don't have to erect one 60 feet in the air to work stations. I erected a simple 20 meter shortened dipole only 5 feet in the air and worked into
    Germany with only 5 watts. He gave me an honest 579 signal report. How good is that from eastern PA?

    A vertical is also very good but you need ground radials. No big deal but don't think you can erect a 1/4 wave vertical with no radials and expect it to
    be efficient.

    Your subject title answered your own question. "Dipole"

    Barry, KU3X/QRP

     
    K7WFM and K0UO like this.
  4. W5HV

    W5HV Ham Member QRZ Page

    Thanks for the info very helpful Robert W5HV
     
  5. W7HV

    W7HV Ham Member QRZ Page

    Nice call, W5HV. Just 2 short of perfection.
     
    W5HV and WE4E like this.
  6. W5HV

    W5HV Ham Member QRZ Page

    yea i like high voltage
     
  7. KG7WGX

    KG7WGX XML Subscriber QRZ Page

    SOTABeams makes a 40/20m "Bandhopper", which is a linked dipole design. It is designed to work with a 20 ft mast if you can't hang it from a tree, rigged in an "inverted - V" shape. Even a lightweight mast will support this antenna, which uses 26 gauge wire and RG-174 coax. The balun at the feed point is just epoxy-coated instead of being housed in a plastic box. Even the tie-out cords are very small diameter.

    You can also make your own version of this, if you want to either save money or make one with less fragile components.

    I'm building a 40/20m linked dipole right now, using a Balun Designs balun, 18 gauge wire and plastic guyline tighteners as insulators. Instead of alligator clips, I'm going to use Powerpole connectors. For tie-out, I am using 3/32" paracord.

    The mast I have is a 20 ft carbon-fiber fishing rod, shortened from its original 32 ft length to get a larger mast top section. It works fine with a 35 ft 18 gauge EF random and I hope it will also support the dipole.

    You do have to drop the antenna and connect/disconnect the links to change bands. However, I find that I usually use 20m for daytime and 40m for evening, so this isn't something I have to do frequently.
     
  8. K2WPM

    K2WPM XML Subscriber QRZ Page

    Here's a good article discussing the perfect portable antenna.
    http://nm9j.com/pcara/docs/pcud0421.pdf
    page 9
    Basically, it is easily made, a linked dipole.
    When I use as vee, I can lower it, change band and raise it in 5 minutes.
    My innovations:
    1. Use carabiners to connect the segments. So, if I don't plan to operate 75/80 meters, I simply leave those segments in the bag. Much lighter antenna.
    2. Added a separate 5 foot segment for 80 meter CW. Again, if I don't plan to do CW, I leave those segments in the bag.
    Yours would be even easier, just create the 20 and 40 meter segments.

    My other portable antenna is 111 foot doublet, fed with 40 feet 450 ohm stranded ladder line, into 1:1 balun, three-foot coax jumper, and I use MFJ 939 auto tuner. Real easy.

    I prefer the linked dipole; slightly better results on 75/80; and on 40 and 20, I like to know where my signal is going.

    Have fun and 73,
    David K2WPM
     
  9. KK4OBI

    KK4OBI Ham Member QRZ Page

    in portable operations getting a dipole up high enough to be seriously directional is the main problem The classic solution is to have a significant amount of the dipole as close to vertical as practical. This gives more omnidirectional radiation for distance communication.

    With only one support like pole or tree the inverted-V is common. Even better is to run the dipole straight up the pole then slope away from the top. With two supports the inverted-L is optimal. The difficulty is keeping the feed line away from the wires so there is minimal coupling which can really make tuning a problem.

    In recent years the developments in the (near-) End Fed Half Wave type that has opened the doors to a no-tuner, multi-band, no-brainer antenna that has the same performance of a mono-band, center-fed half-wave dipole. This solves the feed line deployment concerns, does not need radials and gives the bonus of instant switching up to 8 harmonic bands.
     
  10. W5HV

    W5HV Ham Member QRZ Page

    very interesting thanks for the input
     

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