G5RV or OFCD Windom

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KF5LJW, Apr 12, 2015.

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  1. K7TRF

    K7TRF Premium Subscriber QRZ Page

    For support of 2 to maybe five bands without needing a tuner (fewer bands tends to be easier) I'd add:

    4. A set of resonant parallel dipoles (aka fan dipole).

    A handful of HF bands isn't too tough with fairly simple antennas. Full coverage of every HF band or harder yet, continuous coverage of all HF frequencies with an efficient antenna (e.g. no resistive loads to yield wide SWR bandwidth) is much harder without something like a log periodic array mentioned above.
  2. OK1XD

    OK1XD XML Subscriber QRZ Page

    Hi guys.
    The answer is: OCFD
    I can little compare and tell you the results in real practice from my side. I have both antennas, both were installed in my garden in the same height (+-35ft) as a flat top. Both having the same type of RG213 coax with +- the same lenght to radio. There I simply swith them so I see the differences in real time.
    The OCFD Windom wins.
    BUT I must say that I use the Double Windom which is much better than other models (just let you work on ALL bands)
    This is the Windom I use:

    The only thing you need is a good 6:1 balun (not 4:1!!) and good wire.
    I' ve tested other versions too and after years of testing various types of multiband dipoles I must say that the Double Windom has the best results. I've worked over 250 countries on it with only 100W max.
    In this configuration (pic above) I work all bands. With my MFJ993b tuner I work 60m too with surprisingly very good results. Also the MFJ tune this antenna on 160m - althought I did not expect to be working well, I did some nice DX contacts as well to all continents on 160m.
    But to make this Double Windom resonant also on 160m, you can double the lenght of horizontal wire and you are in.
    So that's my 2 cents, I use the Double Windom as my main antenna (I made two pieces one in N-S one in W-E directions)
    I took the G5RV down (needed the telescopic fiberglass mast for another project as they are not cheap lol) but I hung the G5RV on other place and I use it as a backup antenna.
    Off topic: I have also other antennas like FAN dipole and Cobweb, they are excellent, but they are of course limited by number of bands (used wires) If you need great working simple antenna for ALL bands in one, then the Double Windom is unbeatable.
    If you have a little bit more of space, the great combination is the Windom for lower bands plus for upper bands - 20 to 6m the Cobweb - fantastic antenna, cheap and easy to build too, you just need a good 1:4 balun (not 4:1!!! because you need to make 12,5ohm to 50ohm in case of Cobweb), some heavy duty fiberglass rods and wire. But that's another story.

    73 Jan
    K2WPM likes this.
  3. OK1XD

    OK1XD XML Subscriber QRZ Page

    just more 2 cents add..
    I just played with MSPAINT and did this modest layout.
    If somebody plans to make G5RV antenna, forgot it. Make the ZS6BKW. If somebody wants to build an antenna for a few bucks and wants to put his signal around the globe, ZS6BKW is the fine solution. It gave me many contacts around the globe from ZL to VP8 with low power. Of course, Double Windom is a bit better, but it is also a bit more complex.

    K2WPM likes this.
  4. W2AAT

    W2AAT XML Subscriber QRZ Page

    Again....... W5GI Mystery Antenna!
  5. WA7ARK

    WA7ARK Ham Member QRZ Page

    Hi Jan, I created an AutoEz/Nec2 model for the double windom as shown in the linked figure in post # 42:

    Looks like this when driven at 7.1MHz (note the two half-waves):

    Here are the parameters that describe it:

    I calculated a wide frequency sweep all the way from 3.5 to 29MHz, in steps of 0.1MHz. Here are overlayed plots of SWR50 at the coax side of four different baluns that are right at the feedpoint. The four trial baluns where 1:1, 1:2, 1:4 and 1:6 .

    According to this simulation, the 1:4 is a better choice than a 1:6. Even a 1:2 looks better than the 1:6.
    AJ4WC likes this.
  6. W4HWD

    W4HWD Platinum Subscriber Platinum Subscriber QRZ Page

    I’ve never had an OCF dipole but I do have a G5RV and am plenty pleased with it. It works fine for the bands I use it on - 80,40,20 and 17. I’m not gonna pull it down to try a windom cuz I ain’t into fixing what’s not broke.

    When you try to cover ALL bands with one antenna you are going to be disappointed somewhere...like trying to jam the square 30m peg into the round 10m hole:confused:
  7. OK1XD

    OK1XD XML Subscriber QRZ Page

    Hi Mike, yes, I was dealing between 4:1 and 6:1 too. I spent two days in my garden testing both baluns on the Double Windom and also with "single" Windom which was installed in other side of my garden. So far I tried, the 6:1 balun was fine on Double Windom, the 4:1 with single Windom for me. I did never computer simulations on my own, my way is pretty oldfashioned just cut it-hang it-analyze it-measure it (and again and again if needed) and try it with radio with or without tuner on all bands and make real contacts. Yes, it is very long process but it give me some kind of satisfaction. (unlike to my XYL:D:D)
    So, I can not say what is correct by the simulation nor I´m not an antenna master, I am just a "player" who tries to find the best solution in real operation depending on my conditions and limitations.
    You know, the final result is always very individual (nearby objects, heights, quality of ground, wire size and more surrounding things) so the parameters may vary anytime, anywhere o_O:D
    I did not try the 2:1 but both 4:1 and 6:1 and with 6:1 balun 80m has SWR 1.7, 40m 1.4, 30m 1.1, 20m 1.4, 17m 1.6, 15m 2.0, 12m 1.5 and 10m in CW section 1.2. This is what my meter said then and say now. I remember that with 4:1 it was worse on most bands on the double Windom. So I install the 4:1 back on single Windom and it was OK. I operated both antennas for 2 months simultaneously before I put the single version down.
    So I don´t know why, maybe I am completely wrong, but 6:1 works much better for my piece of the Double Windom.:)
  8. OK1XD

    OK1XD XML Subscriber QRZ Page

    Very true, it is always about to find the best compromise. In my particular case my double Windom works as I wrote above plus with external tuner I work also 60m. And it works mysteriously UFB despite to higher swr. Worked all continents on 60m and 120 countries (till today) using only low power. I don´t know why, maybe my particular 2xWindom is somehow magical:D:D
    Also, I tried to tune it on 160m with external ATU and... it works:eek: Of course, with low efficienty due to non resonant/unproper lengt and even very bad height for 160m-just 36ft above the ground, but I worked somehow all continents and many W and JA stations.
    BUT I must note one very important thing that helps me very much - my QTH is on higher place with omnidirectional clear view with almost no obstacles and my 40.000 sq tf garden with quality soil allows me to place the antennas apart enough.

    So Harry if you have some more space, you can try to build the Double Windom and keep your G5RV too - but rebuild it into ZS6BKW´s version. Depending on your local condition one antenna would work better on one band and the second antenna better elsewhere.;)
    W4HWD likes this.

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