Ionopheric Propagation of Dipoles (

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  • Опубликовано: 14 янв 2025

Комментарии • 38

  • @davidsradioroom9678
    @davidsradioroom9678 3 года назад +3

    Thanks for a really good explanation!

  • @supremetalentco
    @supremetalentco 3 года назад

    Thanks very much Dave. That explains a lot of why some stations hear me and others don't.

  • @SteveBrace
    @SteveBrace 3 года назад +4

    I'm setting up my first HF station and this has helped me a great deal. BTW the UK is a mix of freedom units and metric... We buy fuel in litres and measure speed in MPH :) M7ICY

    • @davidsradioroom9678
      @davidsradioroom9678 3 года назад +2

      Go figure.

    • @davidsaunders1125
      @davidsaunders1125 3 года назад +1

      But measure engine capacity in cc, s!

    • @SteveBrace
      @SteveBrace 3 года назад +2

      @@davidsaunders1125 Also buying food in grammes and weigh ourselves in St & Lbs!

    • @markramsay6399
      @markramsay6399 3 года назад

      In the UK I meet many folk that still think of high summer temp (yes rare but does happen ! ) in F, but think of cold temp below zero in C ..

  • @timmartin1395
    @timmartin1395 3 года назад

    Dave, words could not begin to fully express how much your teaching videos are appreciated. Each one of them are full of great information and easily followed. Some of them are best to watch many times until I fully grasp everything. I wish all your episodes could be catalogued in Ham Radio learning library in a DVD format or something. I'm sure Ham Clubs would greatly enjoy each nicely brief episode at meetings .
    Your efforts will bless Hams old and young for a very long time.
    I will be pleased to send you a donation to the tip jar again. Blessings !!
    N4TDM
    Tim
    Rockingham, NC

    • @jameshollen9723
      @jameshollen9723 3 года назад

      Hello Tim. I live in High Point. Just about to get my HF Yaesu radio from DX Engineering. Already have a "My Antennas" EFHW 40 meter dipole

  • @royceweslowski3730
    @royceweslowski3730 Год назад

    Good video. When I was young I was learning standard measurements in school and then Metric was introduced. 73. VE5RWW.

  • @RB9522
    @RB9522 3 года назад +2

    David, the US may be an imperial hold out but almost the entire world is stuck with imperial water pipes! No one has figured out how to mix metric and inch water pipes. Yes, there are close equivalents.

  • @qutips33
    @qutips33 3 года назад +1

    I have had several contacts to Japan from northern Norway with a dipole 40/20 just 5 meters above the ground .la2vla

  • @todd9524
    @todd9524 3 года назад

    Thank you~!

  • @prasadasgoa
    @prasadasgoa 3 года назад

    Thanks for this and many other educational videos.. (which I have viewed so far.)

  • @5b4aezmarinoscyprus71
    @5b4aezmarinoscyprus71 3 года назад

    Hi Dave, a very educational video, especially for the newcomers. How about a video for LDEs (Long Delayed Echoes) and NVIS (Near Vertical Incident System) antennas.
    73s and stay healthy
    Marinos

  • @forgetyourlife
    @forgetyourlife 3 года назад +2

    Again with the Aluminum.

  • @paulaubuchon2336
    @paulaubuchon2336 3 года назад

    Great job at getting me refreshed on dipoles.
    73. Paul K1YOU

  • @Motham51
    @Motham51 3 года назад

    Some local hams and I were rag-chewing on 10m one night when a ham from New Zealand came on, we each got to put him in our logbooks.
    That was the furthest QSO I've had.

  • @TFuzz58
    @TFuzz58 3 года назад

    As always, excellent video Dave.
    Cheers from Moose Jaw

  • @Siskiyous6
    @Siskiyous6 3 года назад

    My 2 Meter Dipole is made of 1 inch aluminum tubing, and I orient it vertically. At 40 feet I have gotten simplex contact at 30 miles using 5 watts. I see very little about vertical dipoles, but I know I have read about them. My 144 foot doublet is E/W,, but gives me the West Coast really well from Southern Oregon, no way to put a god Doublet N/S here, and there is not a lot to the west here anyways. WS7PB 73.

  • @markramsay6399
    @markramsay6399 3 года назад

    Great video as always. Aside... I am reminded of a Mars mission where the probe crashed due to a mix up between metric and imperial units. Either is OK as long as you know what you are using !! It is a funny world too. The official unit of altitude for aviation around the world is feet !

  • @bruceblosser2040
    @bruceblosser2040 3 года назад

    Fun thing about talking to South Africa etc., is that at least several of those hops to and from the ionosphere, will be over the Pacific Ocean, which is a much better reflector of radio waves, than is the earth! I have heard several South Africa stations on 40 Meters, but haven't made contact yet, as I have a terrible antenna! :) -bruce AI6XK

  • @andycampbell5416
    @andycampbell5416 3 года назад

    Hi,,, many thanks for excellent educational videos,,,, a quick question if I may? I'm using a 40m ocf dipole, now I have it set up north to south, but my lot only allows me to run the long element half of its length before I have to turn it 90 degrees east and support it on two carbon fibre poles about 20 foot high, insulated of course,,,, question is,,, what effect will having the wire in an equal L shape have on radiation pattern, direction, swr etc? Cheers Dave,,, from a UK Oggie 😝😝 M7SPE

  • @stevedowler2366
    @stevedowler2366 3 года назад

    great explanations, Dave, thank you. My dipole (Alpha Delta DX-CC) is over slanted ground, dropping at about 30deg to the East from my home. There are a number of trees and I string it at about 1/2 Lambda height across 3 trees with the center feed point and ends on pulleys so I can fiddle the length for 80M. And I do just fold back a little or let out a little to do those adjustments, sometimes just bunching up in the middle or anywhere along each leg. Question is: it is closer to the ground upslope and farther downslope. Is there any degradation due to that/ Cheers, Steve K0HAY

  • @kent-ka4fix391
    @kent-ka4fix391 3 года назад

    Dave loved the video, but have a question. You say the dipole is pretty much omni directional, but your diagram shows the lobes at right angles to the antenna length, and there is only some propagation at the nulls. At the end you say positioning the antenna north/south will get you east/west propagation. So how much radiation (percentage) do you really get at the nulls, and is it then really omni-directional. Seems that dipole orientation is important depending on where you want the contacts to be.
    Thanks for all you do.

  • @loganv0410
    @loganv0410 3 года назад +1

    The world can be readily divided into two camps: 1 is those who use metric and 2 is those who have landed humans on the moon.

    • @pomchan4704
      @pomchan4704 3 года назад

      Interesting comment. Since the "guys who landed on the moon" used metric.

  • @garrysekelli6776
    @garrysekelli6776 3 года назад

    Im an oggie. Im studying for My ham radio liscentiousness. I have a question. Is it possible to make a tripole antenna? Like a three angled dipole.

    • @greglawrencemusic
      @greglawrencemusic 3 года назад

      That would be what is known as a loop antenna.
      The are triangular, square, rectangular, and round designs.
      A rule of thumb: There are as many antenna designs as there are HAMs.
      Good luck on your exam!
      '73

    • @garrysekelli6776
      @garrysekelli6776 3 года назад

      @@greglawrencemusic i want a pentagramyl antenna. Because i work for central intelligence at the pentagram. I work for the government and am a markist official. I just wish that People would take me seriously as a transgender circus worker individual.

    • @greglawrencemusic
      @greglawrencemusic 3 года назад

      @@garrysekelli6776 That would still be considered a loop.

  • @darinhitchings7104
    @darinhitchings7104 2 года назад

    Very interesting. Thanks for some extra class material: ordinary/ extraordinary waves... (I'm a general). I'm a systems engineer and I challenge myself to work in both systems at least wrt weights, lengths and volumes... So why don't you just give both values? Even if I was at a party or something and being a nerd I might say "so it's 200 miles ... or about 320 km" = (1 + 0.5 + 0.1) * 200 as I think about it. If precision is important it's a quick calculation to do. I used to have a "to meters" type program on my HP48G calculator in school that would take the last number on the stack, pop it, multiply it by a ratio, and then push it back. With the assumption implicitly being it was in imperial units to start with. These days I might use a python shell or Matlab or just ask Google "66 ft in meters". For my purposes I'd say divide 66 ft by 3 that's 22. Divide 66 by 4 that's 17.5. Now take 2/3 of 22 and 1/3 of 17.5 and guesstimate say 19-20 m. Close enough. I do that in the middle of a conversation in my head though it might take me 10 sec. Otherwise get a calculator. In my phd program almost everyone was used to metric units besides me... it's a superior system. So give both. My 2 cents.

    • @davecasler
      @davecasler  2 года назад +1

      Metric is indeed superior and, like you, I used them in engineering. The USA is about the only country still resisting the metric transition. But any backyard mechanic has both metric and imperial tools.

  • @johnward7894
    @johnward7894 3 года назад

    One day the arrl it's going to have you do a monthly article you watch in the qst

  • @georgemoomaw9437
    @georgemoomaw9437 3 года назад +1

    “In the U S people don’t have a good metric intuition” ?? Dave, have we met? That sure describes me.

  • @lyfandeth
    @lyfandeth 3 года назад

    Dave, 25% of your users would appreciate $10 worth of channel funds buying a cheap calculator. Or the app on your computer. Taking a minute to throw in metrics won't scare off too many Americans.

  • @ProperLogicalDebate
    @ProperLogicalDebate 3 года назад

    I know that there's about a 10% difference between a meter and a yard but when someone speaks of kilometers I either think of 0.6 miles or Kiloyards. LoL

  • @sammiller6631
    @sammiller6631 3 года назад

    So why do people insist on calling US units "Imperial" when they are precise about everything else? It's sloppy and confusing. The United States never used Imperial units. US gained independence in the 18th century, using units based from the 15th century. Imperial was invented in the 19th century, over a half century after the US declared independence, who had no use for them.