A Better Off-Centre Fed Dipole - Part 1 (4:1 Transformer & 1:1 Choke / Balun Build)

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  • เผยแพร่เมื่อ 24 ธ.ค. 2024

ความคิดเห็น • 48

  • @petergrimmond2104
    @petergrimmond2104 2 ปีที่แล้ว +4

    Great Video. Not full of crap about yourself like most others. Just facts on the subject. 10/10

    • @ianxfs
      @ianxfs  2 ปีที่แล้ว

      Thanks Peter 😀

  • @timg5tm941
    @timg5tm941 3 ปีที่แล้ว +2

    Excellent presentation Ian, thanks.

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว +1

      Thanks Tim!

  • @M7BCN
    @M7BCN 3 ปีที่แล้ว +2

    Brilliant, looking forward to part two. Thanks Ian.

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว

      Thanks Brian!

  • @gbamck
    @gbamck 3 ปีที่แล้ว +1

    Cheers for the video, Ian.
    Nice job 👍
    Mick

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว +1

      Thanks Mick!

  • @DonDegidio
    @DonDegidio 3 ปีที่แล้ว +1

    Hi Ian
    Excellent build instructions. Looking forward to part 2. You and the family stay safe. 73 WJ3U

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว

      Roger that Don. You too 👍🏻

  • @boxingday11
    @boxingday11 3 ปีที่แล้ว +1

    Thanks Ian,great upload as always 👍🇬🇧

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว

      Thanks!

  • @adamap2796
    @adamap2796 3 ปีที่แล้ว +2

    Thanks Ian, looking forward to part 2. I have an OCFD here with the shorter end from the chimney resulting in the feed point at a good location to the upstairs shack at the back of the house. I also use around 220W from a Yaesu FT1000 MP MKV , into a virtually identical arrangement based on Peters website. I have not noticed any heating effects although the winding insulation appears to have suffered all little from UV.

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว

      Thanks Adam. Yes, looking good so far 👍🏻

  • @TomG2NV
    @TomG2NV 3 ปีที่แล้ว +1

    First class as per usual Ian! 73,

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว

      Thanks Tom!

  • @mike-M0MSN
    @mike-M0MSN 3 ปีที่แล้ว +1

    Super video Ian, I will have to try this. 👍

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว

      Thanks Mike! Part 2 coming soon 🎥

  • @M0RMY
    @M0RMY 3 ปีที่แล้ว +1

    Very informative Ian. Great for loops as you say.

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว

      Thanks Tom!

  • @stephennelson-smith3312
    @stephennelson-smith3312 2 ปีที่แล้ว

    Excellent video - I really like your matter-of-fact presentation, and clear diagrams. Really good balance - already subscribed, and glad I did :)

    • @ianxfs
      @ianxfs  2 ปีที่แล้ว

      Thanks Stephen! Nice to have good feedback 👍🏻

  • @ingeniousys
    @ingeniousys 5 หลายเดือนก่อน +1

    Nice video. I have one question/concern about the design, though.... Would it be more appropriate to switch the order of the two cores so that the 1:1 current balun (choke) is attached at the antenna side of the pair to convert the 200-ohm BALanced load to 200-ohm UNbalanced, then with the second core, transform the 200-ohm UNbalanced to 50-ohm UNbalanced? (So that the order is 1:1 BALUN to 4:1 UNUN with the antenna side being 200-ohm BALanced and the transceiver side being 50-ohm UNbalanced.) The way it is presented, as I understand it, in the video, the 4:1 UNUN is being used on the BALanced side of the circuit rather than the UNbalanced side of the circuit. This doesn't seem quite right to me, but maybe you have a good reason for it that I am not seeing?

    • @ianxfs
      @ianxfs  5 หลายเดือนก่อน

      You could possibly reverse them as you suggest I suspect, but then the 1:1 would need to be designed for 200Ohm? This version copies the 1:1 50Ohm I’ve successfully used on my 80m dipole. After some years of use I can confirm that it performs really well and is my go-to main antenna 👍🏻 Thanks for commenting 😀

  • @Hoverin67
    @Hoverin67 ปีที่แล้ว +1

    Awesome, thanks very much. 👍

    • @ianxfs
      @ianxfs  ปีที่แล้ว

      Thanks!

  • @ranger44881
    @ranger44881 ปีที่แล้ว +1

    Two questions: 1. How many watts is this design good for? 2. Could I fold them over and tuck them in a waterproof enclosure?

    • @ianxfs
      @ianxfs  ปีที่แล้ว

      Hi. Good for UK 400w limit (you can stack for higher powers). Yes you can stack the two, but ensure there’s a breather hole in the box for condensation to escape due to heating and cooling of the air inside. No box is fine and less weight. Good luck 👍🏻

  • @duartebettencourt349
    @duartebettencourt349 2 ปีที่แล้ว +1

    Hello sir.
    I followed your video but I think I must have made a mistake, I am going to verify all the windings are correct. However I have one question, when using the analizer did use the radio coax or just a wip for the testing, and also what lenght of coax will be necessary to do the job right?
    Thank you in advance
    Kb1mlq
    73's

    • @ianxfs
      @ianxfs  2 ปีที่แล้ว +1

      Just a small patch-lead I had to hand Duarte, nothing special. Good luck with yours 👍🏻

  • @duartebettencourt349
    @duartebettencourt349 2 ปีที่แล้ว +1

    Hello! Would this work on a center fed dipole, the reason I ask os because I am limited on space to mount an off center fed dipole.
    Thank you
    kb1mlq

    • @ianxfs
      @ianxfs  2 ปีที่แล้ว

      Hi Duarte. I’m not sure what you mean as both a centre-fed and off-centre fed are both the same length, but the off-centre gives you extra bands on the harmonics. A trap-dipole will be shorter if you’re tight on space. Good luck!

    • @duartebettencourt349
      @duartebettencourt349 2 ปีที่แล้ว +1

      Hello and thank you for the reply, the reason is the off center fed dipole is longer on one leg and that is where I have the problem, the center fed it is equal on both sides and that gives me more room to install where I want the feed point at.
      Thank you so much for your prompt response
      Duarte Bettencourt
      KB1MLQ

  • @samgrieg
    @samgrieg 2 ปีที่แล้ว +1

    Is it required for black wire to be connected to center and red to shield?

    • @ianxfs
      @ianxfs  2 ปีที่แล้ว

      Hi Sam, it’s the positioning of the wires and not the colours. This red/black combination mirrors a previous balun video and links back to Pater’s channel. I kept things the same so they match each other. Thanks.

  • @thepctech
    @thepctech ปีที่แล้ว

    Do you have good instructions on a web page, not just the video? I'd like to print them off for reference when i build mine.

    • @ianxfs
      @ianxfs  ปีที่แล้ว

      No sorry, just the video.

  • @DrHWO
    @DrHWO 3 ปีที่แล้ว +1

    Excellent presentation Ian. I appreciate that the proof of the pudding is in the eating, but were you able to measure the choking capacity of your 1:1 across the bands?………………
    Or am I being too pedantic?

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว

      Good question! If you watch Peter’s video (link in description) you can see his full range of measurements, (including choking). If I recall it is over -30dB from 7MHz up 🤔

  • @ironton655
    @ironton655 10 หลายเดือนก่อน +1

    The 1:1 choke would be much better if it was wound with 50 ohm, Teflon insulated coax. The double, bifilar windings like you have shown paralleled only have half the common mode impedance and a single bifilar winding much the same as putting 2 resistors in parallel. The coax is easier to wind and much more effective.

    • @ianxfs
      @ianxfs  10 หลายเดือนก่อน

      Thanks for the info! Note also that this choke doubles as a balun.

  • @HughJarse1968
    @HughJarse1968 ปีที่แล้ว +1

    Hi, can anyone tell me please, does the 1:1 balun need exactly 12 turns? I can only fit about 10 turns per side on my ferrite core - does it matter?
    Many thanks :)

    • @ianxfs
      @ianxfs  ปีที่แล้ว

      Keep trying Dave. It stretches the outer cover when you’ve given it a go. Really tight and it’ll go on I’m sure….I had several attempts….

    • @HughJarse1968
      @HughJarse1968 ปีที่แล้ว +1

      Cheers, will do :)

  • @AB1Vampire
    @AB1Vampire 4 หลายเดือนก่อน +1

    Thanks for the explanation, I watched Peter's video but was better able to understand your explanation sans theory.

    • @ianxfs
      @ianxfs  4 หลายเดือนก่อน

      @@AB1Vampire Great, thanks.

  • @michealbell5042
    @michealbell5042 3 ปีที่แล้ว +1

    I just copied your examples the 4:1 is brilliant I don't think my 1:1 is as good but is useful up to 6 meter .👍

    • @ianxfs
      @ianxfs  3 ปีที่แล้ว

      Great Michael 👍🏻