• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Notice: You may not use this site to facilitate the unauthorized selling of copyrighted material including, but not limited to, in the public dxForums, dxGallery, dxChat and private messsages. If you get caught doing this, you will be permanently banned with no second chances. A notice will be placed on the site of why you were banned and any information collected by this site about you will be made known to the copyright holder.

Search results

  1. T

    Base Imax Antenna current distribution with and without capacitor

    I thought I lost all of these models, but apparently I haven't. I'm not sure when I made them, but it is in a folder listed as before 2020 models. One thing I am certain of is it isn't my original imax models meant to test weather a capacitor was present or not, the techniques I used are more...
  2. T

    Is resonance really where you get best antenna performance?

    I know, there are a lot of people that will quickly say yes and move on. I was once one of them. I note that it is interesting that no one that said tuning for "resonance" is always the best has been able to actually show this. They believe it to the core and can often give hypothetical...
  3. T

    Playing around with my new nanovna

    I just received a nanovna, which costs a whole $50 or so, and some hardware needed to make it work. To think a $50 device is comparable, and in some ways even more powerful than a $600 AIM4170 from 5 or 6 years ago... Just a quick few pics from me playing with two different antennas...
  4. T

    Base Gamma match on Vector antenna models

    In a thread on Marconi's I-10k model I was asked about my modeling of a fully functional gamma match. I decided to create a new thread as this is a model of a different antenna. Enjoy the video. The DB
  5. T

    Suv models

    About a year ago I converted the 102" whip +6" riser I was using for CB on my SUV into a ham antenna by adding a remote autotuner right at the feed point. Thus far I've made contacts on 20 through 80 meters. Today I remade my SUV model for 4nec2. I had to remake it as I lost all of the models...
  6. T

    Miscellaneous modeling stuff.

    Here I am putting some modeling stuff that is unrelated to other threads. Bob85 a note, I will likely add your Starduster model request here. To start I am going to show test model results for angled radials. This is on a Starduster type antenna, although these have four radials instead of...
  7. T

    A really good video I happened across.

    This video, while long, shows many aspects of antennas and transmission lines. If you want to understand antenna systems in general, this is a great place to start. If you want you can skip past the first six and a half minutes or so as they just introduce the guy who is presenting the video...
  8. T

    Choke placement for a sleeve dipole for HomerBB.

    I like the idea, and done. The sleeved dipole, this antenna took some work on figuring out the proper choking method... As I did before, lets start out with an example of a worse case scanerio... As we can see, large common mode currents. And choking at the bottom of the sleeve does...
  9. T

    Different installations of the Imax antenna at different heights.

    For a while I (well me and some others on this forum) knew that there was a capacitor on the radiating element of the Imax antenna, we even knew where it was, but we didn't know its size. 357 came through with its size a while back, and I made an initial model based on that, and its results...
  10. T

    I-10K/Sockwave model first run

    I was attempting to make a model of a .625 wavelength antenna that included a trombone style matching system as found on the I-10K and Shockwave antennas, and I succeeded, although it took me a while to get the model to tune properly. The first image will show the layout and the current...
  11. T

    Modeling my Ford Explorer

    Today I finished putting together a model of my Ford Explorer. These are the results from said model. First, this is what the model looks like with a 1/4 wavelength antenna on the middle of the roof. I have three models based on this object, one with the antenna on the middle of the roof, as...
  12. T

    NEC2 and groundwave

    I was asked by Henry HPSD to confirm the ground wave accuracy of NEC2 based models (such as 4NEC2) before I start reporting information based on it. I've done some research and found that there really isn't much info on it out there. Henry has used (or has at least referenced) EZNEC Pro to me...
  13. T

    The Open Stub J-pole

    A friend is making and selling these Open Stub J-Poles that you can find directions for on-line. The question is does this description accurately reflect how this antenna actually works? I personally think that, despite the design's looks, that the name given to this antenna is in error. I'm...
  14. T

    NEC2 cage experiment

    Did an experiment with NEC2 and out of phase elements in the form of a cage. To create the cage I used elements surrounding a central element, and driven 180 degrees out of phase. I created these models in freespace, not that that will affect anything here as what we are interested in is the...
  15. T

    Question on the Vector

    It has been described that the basket area of the Vector acts in some ways like a coaxial feedline with separate currents on the inside and outside of the basket. That is fine, but... What keeps the currents on the inside and outside of said basket on their respective sides? With a coax, or a...
  16. T

    Tuner efficiency

    Following a rather intense debate between two friends of mine about how efficient an antenna tuner actually is, and sketchy info at best on loss characteristics of tuners in general, this weekend I plan on running some scans for return loss through my MFJ Deluxe Versa Tuner II (MFJ-949E) tuner...
  17. T

    Fun with Standing Waves...

    The standing waves used for this follow the same principles as standing waves in the feedlines we use... ... The DB
  18. T

    Went to help out with two tower removals...

    I went to the house of a former ham to help take down some towers his wife was letting us have. Anything we didn't want would be scrapped... The first tower we removed is a 40 foot fold over and crank up tower. That is going to Jim, the head of the antennas team. And the poll it was...
  19. T

    Radial length and angle radiation patterns... Long...

    I was modeling different sized and angles for radials for a 5/8 wavelength antenna and opted to put this information here to make it easier for people who are interested to find... Some info on the models first. The base of the 5/8 wavelength vertical section is 1 wavelength above average...
  20. T

    Got a new (well old really) toy...

    Should be fun to play with, and see how accurate it still is in comparison to much newer equipment including a modern day VNA. Only cost me $20 including a full set of inductors. Manufacturer: James Million MFG Company Type: 90551 The on-line manual I found has a date in it, 3-25-65...