Ham Radio - An end fed folded dipole experiment. Part 1, the idea and design.

Discussion in 'Amateur Radio News' started by KB7TBT, Jul 7, 2019.

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  1. KG5KPU

    KG5KPU XML Subscriber QRZ Page

    Sure, we can add "end Fed Zepp" into the group of end-fed antennas that aren't a long or random wire. :) :) :)
     
  2. K2XT

    K2XT Premium Subscriber QRZ Page

    So, I see there is a part two followup to the original video.
    And the experiment failed.
    You could knock me over with a feather.
     
    K4AGO, WN1MB and W4AEE like this.
  3. WA3YRE

    WA3YRE Ham Member QRZ Page

    A zepplin antenna can ONLY be end fed. Have a look at a Zepplin sometime and recall they had to use HF for comms and think about how they got an effective antenna for that purpose.
     
  4. WA3YRE

    WA3YRE Ham Member QRZ Page

    The sort of waste of time and energy in the video is what happens when so many so called technical folks do not read things and just "learn" from online videos. So many of the 20-30 something tech folks I work with are constantly re-inventing the wheel because they either can not or will not read existing tech manuals.
     
    W4AEE, AF4RK, K2XT and 4 others like this.
  5. K8AI

    K8AI Ham Member QRZ Page

    At first I was assuming that it was a 1/2 wavelength of balanced line shorted at BOTH ends and "fed" at one of the ends - I was wrong. The OP only shorts it at one end, the fed end. When I heard "folded dipole", I just naturally assumed that each end of both wires would be connected, like a commonly-described folded dipole. My mistake.

    Some are saying that the current in each wire will be differential in phase. How can they be if both wires are "fed" at the exact same electrical node?
     
  6. AF4RK

    AF4RK Ham Member QRZ Page

    OMG! Another one! You know they sell books on this subject.
    AF4RK
     
    W1LWT likes this.
  7. NE4EB

    NE4EB XML Subscriber QRZ Page

    "End Fed Dipole". I didn't need any more information. Then again, I've heard about "Long Wire" 80 meter antennas that are ~40 feet long, counterpoises for same at 12 feet, and people wondering why 10 feet of wire across the side of an apartment wall doesn't let them work that juicy DX.

    Here's my old guy rant.

    This is what happens when people study the answers to the test questions and not the material the test is supposed to determine the test takers understanding of.

    I had an Amateur Extra class operating on LSB on 15 meters calling CQ. I switched over and told him he had the wrong sideband selected. He told me he didn't know how to change that, and what difference did that make, anyway?

    I had a different holder of the same class tell me he had "a license to learn". When I told him that class had an obligation to know enough to teach and help newcomers, he told me "I must be one of them old guys."

    He was right.

    I spend some time and effort helping out our new hams. Trying to put concepts and techniques into terms they can understand. And the appreciation I get for that makes all the bullshit other places worth it.

    Was a green ham myself once and won't ever forget the help I had. But there was an expectation I would invest time in study and practice. I'm sort of stuck on that model.

    73
    Lowell
     
    N0CN likes this.
  8. W4AEE

    W4AEE Ham Member QRZ Page

    The true "ham spirit" is there in anyone wanting to experiment and learn, and I applaud such efforts in most cases. But to just think up something out of the blue and try it (much less publishing a video about it before hand) without first consulting the plethora of basic technical info available on the web, including the hundreds of archived QST articles, handbooks, antenna books, etc., is...well...foolish and a waste of time. And here I am wasting time commenting about it. -W4AEE
     
    KR3DX, VK6APZ, W1LWT and 2 others like this.
  9. KQ6XA

    KQ6XA Ham Member QRZ Page

    Too bad he didn't carry it on far enough to figure out one of the tricks to making it work.
    That would have been both fun to watch and instructive.

    And for those who wonder, yes, there are several ways to match that as an efficient end fed dipole antenna or a loop antenna.
    The easiest method is just a few wire cuts and jumps, at just the right spots in the window line.

    Take 2 ferrites and call the doctor in the morning.
     
    N0CN, W4AEE and K2XT like this.
  10. AB7E

    AB7E Ham Member QRZ Page

    A basic understanding of antennas and transmission lines would save you a lot of blind alleys ... like this one. A half wavelength of any transmission line that is shorted at the far end is going to look like a short at the near end .... guaranteed. This is so fundamental that I don't understand why you would ever think this would work. You might as well just stick a pin in your coax ... same result.
     
    KR3DX, W1LWT, K2XT and 1 other person like this.

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