Shortened EFHW from 40M to 80M with 110uH Loading Coil

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  • Опубліковано 18 лис 2024

КОМЕНТАРІ • 29

  • @trumpdonald6911
    @trumpdonald6911 Рік тому

    I was issued the same jacket you’re wearing while I was in the Army. Loved it.

  • @DK5ONV
    @DK5ONV Рік тому

    Looking great. I am a Wireman, love these Endfed Antennas. I work fulltime portable talking to the whole World with 100W out of the Fields, Woods or along side the Shores of River Areas.. Amazing how well these Antennas work on relatively low heights setup from the Ground. Tnx for this neat Video. 73 de YFUG 💯👍🙋‍♂

    • @n3vanradio
      @n3vanradio  Рік тому +1

      Thank you very much for the comment. This loading coil reduces the length of wire I need at my office so I can still be on the air on 80m. I actually made a smaller version for doing portable ops. I may make a video highlighting it. Same concept building it just smaller pipe and different gauge wire. And yes I agree I absolutely love the EFHW! Thank you and 73, Matt N3VAN

  • @wesmcfarland4106
    @wesmcfarland4106 Рік тому +1

    Outstanding video! Bought the same Proster LCR to check the coil on a MFJ crystal radio kit I just finished. Used it tonight to go through a box of resistors and I'm impressed and definitely the price is right! Got an ARRL endfed kit I'm going to put together soon and definitely want to do this coil mod after I complete it. Have a 130 feet EFHW 7510 from MyAntennas here at the house and my G90 tunes it up great (1.3:1) for the local Emergency Net on 3922. Hoping with this coil I will be able to tune up 75m on the 40m endfed kit for QRP and field day exercises. Hope to see the conclusion of this video soon and see what your end results were. 73 K5WFD

    • @n3vanradio
      @n3vanradio  Рік тому

      The Proster LCR is surprisingly accurate and in my testing better than the UCTRONICS one. Great device to have if you are building antennas.
      I love the EFHW and it is primarily what I use for POTA and doing QRP from remote campsites. Versatile antennas that you can setup in a variety of configurations.
      Will be uploading the installation of the coil in one of the next videos I post.
      Thank you again!

  • @geirha75
    @geirha75 Рік тому

    Thanks for good instructions. My experience with 66pacific calculator is that it gives you a theoretical minimum number of turns. I usually go for more turns and if needed, remove some.

    • @n3vanradio
      @n3vanradio  Рік тому

      You are very welcome! I am building a Shorty 40 soon with a 35uH coil. You are absolutely right that 66 pacific gives you a rough calculation that is close enough to use but always do a few more turns, measure and then unturn.

    • @geirha75
      @geirha75 3 місяці тому

      @@n3vanradio I have built a 116uH coil. I don't want to unwind anymore. Will i need to shortened or extend the tail , the end part of the wire from the coil?

  • @dleecann5795
    @dleecann5795 Рік тому

    Great video..thanks for showing from beginning to end..

  • @MrStanwyck
    @MrStanwyck Рік тому +1

    Great video. Where did you get the info telling you what value of coil you needed to build? I’d like to build one for a 40m half wave end fed. I’d like to know how they arrived at 34uH to make a 40m.

    • @n3vanradio
      @n3vanradio  Рік тому

      Thank you! I found information in the ARRL Antenna Book as well as various documentation on the internet. The 110uH coil allows a 40-10m EFHW antenna to add 80m. The 34uH coil allows a 20-10m EFHW antenna to add 40m. That is why you saw the 34uH coil. It is a slightly different application.
      I am in the process of making a QRP version of the 110uH coil for when I go out and do POTA/SOTA. TY for watching and your question. 73, Matt N3VAN

  • @johnbauman4005
    @johnbauman4005 Рік тому +1

    Hi again, Matt,
    Am finally doing the 110 uH coil today and reviewed this video first.
    Couldn't find a subsequent video where you deployed and/or tested this coil - did I miss it?
    Am interested in what you said about narrow bandwidth at 80 meters when using a coil and how one can get past that with a tuner. Can we get access to all of 80m with a tuner? Have waited to buy a tuner because a lot of folks said it probably wasn't necessary. However if a tuner would increase access/bandwidth significantly I'll get one.
    Appreciate your videos and advice!
    73,
    John - KK7JBZ

    • @n3vanradio
      @n3vanradio  Рік тому +1

      Hi again John!
      I have to finish testing the 110uh, but currently find it has better performance using a 64:1 EFHW transformer than an 49:1 transformer. I have a few videos recorded that I have yet to edit and put into a final video but will get one up in the next few weeks so stay tuned!
      Regarding the narrowness of the 80m portion, yes a tuner would definitely bring the entire band into usability. But I am trying to keep my tuners in ham closet and not used as they induce their own losses in performance. I am working on a QRP version for doing POTA/SOTA, etc.
      Stay tuned and thank you so much for watching!
      73, Matt N3VAN

    • @johnbauman4005
      @johnbauman4005 Рік тому

      @@n3vanradio Thanks, Matt. I'm just trying to get on the air for the first time with the ARRL EFHW at my QTH and want to access as many bands as possible to see what's out there. May get into POTA/SOTA/QRP at some point, but have to walk (crawl?) before I can run.
      I'm subscribed and will keep an eye out for your videos!
      73,
      John

    • @robertmachette836
      @robertmachette836 Рік тому +2

      I saw where a guy added a 500pf capacitor at the halfway point of a 8010, but that wasn’t a half wave. The capacitor moved the res higher in the 80 band without Impacting the higher bands.

    • @vandersoninc
      @vandersoninc Рік тому +1

      @@robertmachette836 Now that is very interesting, I may have to try that!

  • @goffredoprincigalli7030
    @goffredoprincigalli7030 Рік тому +1

    I'd like to add a 40 m coil to a 30m EFHW, how do I know what inductance I need? Do you know a general formula for coil inductance in an efhw?

    • @n3vanradio
      @n3vanradio  Рік тому

      I never tried to extend a 30m EFHW to 40m but I assume it is possible using an inductance coil. Unsure the micro henry's needed for that but with a 30m you should be able to get 60m with a coil much easier!

  • @johnbauman4005
    @johnbauman4005 Рік тому

    Hi Matt,
    Checked out the linked inductance calculator. Seems like it would be more useful if you entered tube diameter, wire gauge and desired impedence in uH and it spit out the number of turns required.
    There is a significant difference in cost of the two meters listed in the description, and the cheaper one (the one you used in the video) also has a resistance setting while the other does not. I already have a multimeter that does resistance.
    What features does the more expensive meter offer over the cheaper meter? Is it more rugged or otherwise of better build quality?
    Thanks,
    John - KK7JBZ

    • @n3vanradio
      @n3vanradio  Рік тому +1

      It would definitely make it easier to enter tube diameter, wire gauge (or measured thickness) and desired impedence in uH to get the required turns. It would take the guess work out when initially checking how many turns it takes.
      The main difference between the two LCR meters is the accuracy. The UCTRONICS has much better accuracy than the cheaper one I use. I wasn't planning on making a ton of the 110uH or 35uH (for shortened 40m) coils so i couldnt justify the higher cost. But yes the UCTRONICS doesnt have the resistance measurement.
      I had to buy one as my multimeters did not have inductance measurement.
      Thank you and 73 Matt N3VAN

  • @AlvinMcManus
    @AlvinMcManus Рік тому

    I can only mount my EFHW 40-10 horizontal @~20 feet up. I have 95ft in clear length so I am thinking this would work to get 80-10, right?

    • @n3vanradio
      @n3vanradio  Рік тому +1

      Yes, this will allow you to get the 80m band however it will be a short sliver of the band in usable SWR but a touchup tuner would get you the entire 80m band.

    • @AlvinMcManus
      @AlvinMcManus Рік тому

      @@n3vanradio Where is the video of you putting this antenna up? I

  • @robertmachette836
    @robertmachette836 Рік тому

    Can you put 100w through that? Making one soon so I guess I’ll find out!

    • @n3vanradio
      @n3vanradio  Рік тому

      I have done 500 watts through this one. It is 18awg enameled copper and I use 18 awg polystealth. No issues so far. Working on a QRP version for doing POTA/SOTA but since it will be 22 awg it will handle at most 150 watts.

  • @AndrewMurphy8383
    @AndrewMurphy8383 Рік тому

    another deal when you let go of the coil it show that it 110 uh that you need at go look at it

  • @AndrewMurphy8383
    @AndrewMurphy8383 Рік тому

    there is two things wrong with your testing holding on the coil is making it conductive and adding inductance two should not be holding it while testing

  • @zsradioham
    @zsradioham 9 місяців тому

    Way too long. Use 50mm former...much shorter and probably wider band cover.

    • @K5QBF
      @K5QBF 9 місяців тому +1

      It doesn’t matter how long it is as long as it’s 110.