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Which antenna analyzer?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by VE6ADZ, Sep 29, 2015.

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  1. AC6LA

    AC6LA Ham Member QRZ Page


    The Zplots application mentioned above, and all the other AC6LA Excel apps, can be used with Excel 97, 2000, 2002, 2003, 2007, 2010, 2013, and 2016. It can also be used with Office 365 which is the "yearly subscription" version as opposed to the traditional "buy it once" version of MS Office.

    If you don't already have Excel and you don't foresee having a need for it other than to run a single application, it would hardly seem worth the bother.

    Dan, AC6LA
  2. W7CJD

    W7CJD Ham Member QRZ Page

    I do not have Excel.

    I get the offer of Office 365 with windows tablets that do not have the resources to run all that.

    I really want to have 4nec2 and Zplots

    I purchased a AOpen 7000. It is only a dual CPU.

    If I have to, I will purchase a AOpen with a quad core CPU. I purchased 8 GB Crucial brand RAM. I will purchase a Crucial SSD.

    If I need more computing power, I have my custom-build PC, which is presently dedicated to RAW format photography.

    I could swap out the high speed Plextor hard drives.

    I want to do antenna modelling because I am so tired of the run around about the few antennas that interest me.

    I am 67 years old: I should live so long to be able to get the answers.

    I want to have the right antenna analyzer, as well.

    This thread has been on the right track, by telling practical use.

    I do like a graphical display, even charts and diagrams are better than technospeak with no glossary at the end.

    I do understand concepts.

    It is the concepts, that I understand.

    I like using computer tablets for requisite software.

    They are much more convenient than sitting at a desktop computer.
  3. KM1H

    KM1H Ham Member QRZ Page

    The CAA-500 Mark II is full page advertised in the 12/15 QST. For that much money Id expect to have the reactance sign included.

  4. KK4WMX

    KK4WMX XML Subscriber QRZ Page

    I also have an AA-170, it has been very useful & zero trouble. Although I do use it "stand-alone" on occasion, I most often use it in the shack tethered to a PC for use with the included AntScope software. I often use 750 to 1000 data points on a full range sweep when connected to the PC, this provides good info for use with the TDR function as well as SWR plots. Such sweeps can be stored as data files and used as background data for comparisons with more concise sweeps when using the dual trace option (load the stored file, then run a new sweep - the result plot will only be as wide as the new sweep but include a background trace of the previously loaded file that overlaps the current freq range). Using the USB connection saves on battery use. You can also use a LI-ON "power bank" portable cell phone recharge unit as an external power source via the USB connector to give you extended run time without using the internal batteries.

  5. N3DT

    N3DT Ham Member QRZ Page

    Thank you Dan. That seems to work quite nicely.
  6. N3DT

    N3DT Ham Member QRZ Page

    Now where did you find that info about looking at 2 plots? My program gets a bit buggy if I try to use the OSL calibration in that mode.
  7. KM3F

    KM3F Ham Member QRZ Page

    I also have the new CAA 500 MK II.
    It has much longer battery life and can sweep several runs in different colors but does not save them as there is no output to down load from.
    Paid less then 400 from HRO for a 1.6 to 500+ range at 1/2 the size of a 259 and much better built with three ways of displaying the SWR and resistance.
    The old 500 is still available.
    See Jan 2016 second page Comet adv. model # and photo
    Good luck.
  8. KK4WMX

    KK4WMX XML Subscriber QRZ Page

    The 2 plots thing is just the view menu "show previous graph" option (also seen as button on tool bar) where the previous viewed graph data shows as a fine line (within the limits of the current freq range) and the current graph data shows as bold.

    I haven't been using the OSL calibration so can't address that part within AntScope. I have read that the calibration transformation is applied only to on-screen & exported (but not saved) data points. I assume you could apply calibration to a plot & export it and then could use ZPlots to do further examination. Not sure about multiple plots in ZPlots, haven't played with it much...

  9. N3DT

    N3DT Ham Member QRZ Page

    Thanks Nick,
    Yes I got the 'previous graph' to work even with the OSL calibration, but of course you have to scan everything in the original number of data points or it won't show (the OSL) apparently. I hadn't seen that option (the previous data) before. It still seems a bit buggy and unless you're paying attention, it's hard to tell which graph is which, but one does show up as a thinner line. I'm sure there's method in the madness somehow. I'll play with it. It's too bad the instruction book doesn't go through much. I was going through the AIM stuff and it looks like there's a lot of good information there. I'd like to figure out how to measure my ground conductivity for one thing. I wish this thing were available 30 years ago. But of course then it would have cost $3K and I couldn't even have afforded the $580 or so I paid for this one back then.

    I'd join the yahoo group, but I hate their interface and when I have joined a group, it keeps dropping me out and I have to keep re-registering, plus I don't seem to get much out of it and there's so much yahoo crap.

    That was one of the first things I did was do an OSL calibration on all my feedlines. It also looks like the ZPlots will do a lot of things that AntScope won't, but it's going to take some reading and playing. Good thing winter is coming on.

    I have an LP100A and it also plots stuff, but it's pretty basic.
  10. AC6LA

    AC6LA Ham Member QRZ Page

    Zplots implements multiple plots with the "Snapshots" feature. Since it's only three paragraphs here's an extract from the Zplots web page:

    Snapshots: This button has two uses. On the Custom XY chart you can use snapshots to plot more than two trace lines at the same time. For example, you could plot Xs on the primary (left scale) axis and take a snapshot. Then plot Rs (again on the left axis) and take another snapshot. Then plot Zmag. While you are doing this you can be showing Theta (for example) on the secondary (right) axis. When you are done you will have four trace lines: Zmag, Rs, and Xs using the left scale and Theta using the right scale. On the Custom XY chart, snapshots 1 and 2 are associated with the primary (left scale) axis; snapshots 3 and 4 are associated with the secondary (right scale) axis.

    On both the Custom XY chart and the Smith chart you can also use snapshots in order to compare data from one sweep against that from another. Snapshot traces persist when you load new data. Hence you can, for example, load data from one file, take a snapshot, load data from a different file, and see how the two compare. If you are using one of the VNA control software programs you could load a "Transmission" type file, take a snapshot, then load a "Reflection" type file and see the S21 and S11 traces overlaid.

    You can also compare data from completely different sources. For example, suppose you modeled an antenna with EZNEC, constructed a "real-world" version of the model, and took some impedance measurements when you were done. You could load the EZNEC SWR sweep data (from LastZ.txt) into Zplots and take one or more snapshots. Then load the data file produced by your AIM or VNA software. Now you can see the difference, hopefully small, between the "as modeled" as "as measured" data. (See below for more on the Zplots 'Add or Subtract Transmission Line' feature which allows you to account for the fact that your modeled impedance [probably] represents the antenna feed point while your measured impedance was [probably] taken at the input end of a feedline.)

    Dan, AC6LA

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