Practical Foil Metal Antennas - John Portune - W6NBC

Ғылым және технология

Hams are used to building antennas out of copper tubing, aluminum tubing and wire.
However, there are other very versatile materials available;
which allow for the construction of some unique antennas.
John, W6NBC, will discuss this subject with a presentation titled “Practical Foil Metal Antennas”.
His presentation contains, among other things, a good technical tutorial covering:
• Tape width and thickness to handle power.
• Skin effect issues.
• Antenna efficiency.
• Examples of how to design various small sized tape HF & VHF antennas.
John has written many articles for QST.
He also has a very interesting web site at www.w6nbc.com

Пікірлер: 25

  • @crazyham
    @crazyhamАй бұрын

    One very interesting thing about using foil tape is that it has a much lower inductance per unit length than a round narrower wire. The wider the tape the lower the indictance per unit length. This can also be very useful depending on your antenna design. You can also use foil tape with a foam double sided tape as the dielectric (in between) as a balanced feeder with a low Charecteristic Impedence. This Paralel line has increased capacitiance and decreased inductance. I have created 50 OHm balanced feedlines with this concept. Great Video Mate & 73 from DownUnder 🇦🇺

  • @allancopland1768
    @allancopland17684 ай бұрын

    Wow! Looking through the questions leads me to think people either never actually watched this or never took in what was being said. It's very informative for the newbie.

  • @grumpyken9151
    @grumpyken915110 ай бұрын

    I've watched some really great videos on your channel regarding small space antennas and this one really inspires some experimentation. very interesting lectures 👍

  • @jkbish1
    @jkbish12 жыл бұрын

    I asked the President of my radio club to review your website. He did and he liked it.

  • @barneymerrill3188
    @barneymerrill3188 Жыл бұрын

    Where do you connect the coax cable at?🤷‍♂️🎙👍

  • @wesKEVQJ
    @wesKEVQJ Жыл бұрын

    Quick question, when you say off center fed, does that mean part below the feed is doubled over and cancels itself out? Does this only radiate from the top? Also curious what difference the pipe diameter makes.

  • @tlebryk
    @tlebryk Жыл бұрын

    What kind of unun or balun is used at the feedpoint? Not enough details to build this.

  • @richard1001001
    @richard1001001Ай бұрын

    Hi. Great antenna. Do you have a formula to calculate the copper tape length for other bands please. Looking to build one for 4M (70mhz) 73 Steve M0UEH

  • @ManuelPinner
    @ManuelPinner Жыл бұрын

    This Type of Antennas can be Use in a Home Owner Association on the Vinal Siding of a House,

  • @timdbl7804
    @timdbl78047 ай бұрын

    Thank you for an informative video. Is the amount of RF loss, in the adhesive on the tape, and in the plastic pipe, significant?

  • @victoryfirst2878
    @victoryfirst28788 ай бұрын

    Very good video Sir. I learned a lot. How did you find this information Sir ???

  • @joes973
    @joes9733 ай бұрын

    I've heard W6NBC reject the idea of a flat conductor magnetic loop due to skin effect on the edges of the conductor, but here, he is promoting a fist conductor on the same bands for vertical dipoles. What am I missing?

  • @BigFireDave
    @BigFireDave Жыл бұрын

    Can anyone answer a question for me. I am in S Fla so the first question on my mind about the use of this tape and weather exposure. How does the tape hold up to water and sunshine?

  • @analog_guy

    @analog_guy

    8 ай бұрын

    The tape holds up just fine, at least in my trial. 🙂 I built a Yagi antenna for the six-meter band, using aluminum foil tape applied to PVC conduit to form the parasitic elements. The tape is 3M type 3340, 2.5 inches wide. The PVC conduit is the grey "1/2 inch" size, which is nearly 7/8 inch in outside diameter. The tape is not wide enough to wrap all the way around the conduit, leaving a gap of exposed PVC at the bottom. I consider the gap to be of no consequence. I laid the tape down in one continuous strip on the upper side of each element from end to end and wrapped the width of the tape around the element so the gap would be on the underside. Using a wood dowel as a burnishing tool, I rubbed the tape firmly all over to assure a good bond everywhere between the tape and PVC. The antenna has been up outside above my house continuously for five years, with no delamination or deterioration of performance. It is exposed to direct sunlight and has experienced summer air temperatures frequently in the upper 90's (as high as 98 degrees F). It has also experienced humidities to 100%, as well as rain, snow, and ice storms, and windstorms that have felled trees and felled large branches in this area. The antenna elements flex in the wind but the tape remains tightly affixed and uncracked. The antenna has the following advantages: quite low cost compared to aluminum tubing and no aluminum-to-aluminum joints that can lose electrical continuity over time. I can't say the PVC would survive a Florida hurricane, but I would expect the tape to remain attached except where the PVC folded or broke!

  • @reylambarte5615
    @reylambarte56158 ай бұрын

    How i may predict the magnitude of the radiation resistance of any antenna

  • @markhall3434
    @markhall3434 Жыл бұрын

    Assuming a HF skin depth on the order of .001 inches, does the RF use both sides of a tape? Does the RF use both inner and outter surfaces of Tube?

  • @markhall3434

    @markhall3434

    Жыл бұрын

    Can multiple tape layers be stacked flat? Is there a layer seperation requirement to minimize skin effects?

  • @markhall3434

    @markhall3434

    Жыл бұрын

    New antenna build material: There is this new Fiberglass ReBar.. I believe 5/8 down to 1/4, although locally haven't seen bigger that 1/2. Very Stiff, but flexes some. I believe I saw 20' lengths although I don't believe you could cantilever that far. For a higher Radiation resistance antenna like a yagi.. Wrapping even a 1/2" with copper tape should be ample. Worthy of consideration!

  • @jdschulteis

    @jdschulteis

    Жыл бұрын

    @@markhall3434 Interesting idea. 1/2" x 10' fiberglass rebar only $5.75 (Lowe's). If I fed the cantilever calculator right it would droop about 17" over the 10', and you are correct that 20' would be too far.

  • @toml.8210
    @toml.82109 ай бұрын

    I thougt this video was to discuss foil antennas for receiving.

  • @GoonyMclinux

    @GoonyMclinux

    8 ай бұрын

    It does, the antenna receives also.

  • @JoelWilhiteKD6W
    @JoelWilhiteKD6W7 ай бұрын

    Do us a favor and please rerecord this video, all the messing around is distracting.

  • @ericm0612
    @ericm0612 Жыл бұрын

    You didn't need 20 min to tell how lol

  • @GoonyMclinux

    @GoonyMclinux

    8 ай бұрын

    I find it comical you watched the entire video without searching for the answers you want by skipping forward in the video and then making fun of the video production. 😂

  • @glitter_fart
    @glitter_fart8 ай бұрын

    ham radio is a dying hobby, not directed at you, but ham's need to stop yelling get off my lawn when asked whats up.

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