Eznec Question

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by K5WZI, Jul 23, 2019.

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  1. UA3TW

    UA3TW Ham Member QRZ Page

    Many thanks, Dan. There is a lot to study... And the conclusion comes to me - do not develop complicated antennas - no way to model them...:(
     
  2. UA3TW

    UA3TW Ham Member QRZ Page

    Hi all.
    When using AutoEZ I made a blunder twice. I wrote some variables in the variables list. Then I wrote them in the wires formulas list as =A and so on and forgot to press Save changes knob. Then I began optimisation prosess.
    When I got some result, I took it as true, and noticed the mistake much later. Dan, is that possible perhaps in later versions to do something about that, to have some warning, that variables change in optimisation table but do not really change?
     
  3. AC6LA

    AC6LA Ham Member QRZ Page

    Well, when the optimizer finishes the variables really have changed. And they will stay changed unless you click either the "Reset to Latest Start Values" button or the "Reset to Selected Log Row" button. But you are correct in that if you close AutoEZ without saving the workbook itself and without using the "Save Model As" button, the changes will not be preserved. The same is true if you make manual changes rather than using the optimizer; you must use the "Save Model As" button.

    I'll think about how to add a warning if any unsaved changes are about to be lost.

    Dan, AC6LA
     
    UA3TW likes this.
  4. UA3TW

    UA3TW Ham Member QRZ Page

    Dan, I think it is reasonable to explain in detail my difficulty on an example. Suppose I took 3el Yagi and began optimizing it only changing the elements lengthes. Then I suddenly desided to add X position of the middle element
    to optimisation. I chose a variable for the X position in the variables list, then I went to the list of wires, switched to "formulas" and replaced the figure for X of this element by the variable. Then I returned to the optimization, but fogot to press "Save changes". I began optimization, where still the lenghes of elements change and the X position changes as well, at least on the variablse table. But it does not really change, but I am not aware. When the optimization is finished, I took the result as geniun truth.
    It already happened . I was optimizing 25-50 broadband transformer of UA6LGO design. The transformer consists of 4 TLs and a cap 470 pF. I began optimizing the TLs lengthes and later added the cap value to optimization.
    But forgot to press "Save changes" after the addition. I got 150 pF as a result in the variables table, whereas the cap remains 470 pF. But I recommended people 150 pF. Had to coorrect later. If I had warning, that the cap value do not really change...
     
  5. AC6LA

    AC6LA Ham Member QRZ Page

    Ah, now I understand the problem. If you were only optimizing the element lengths for a 3el Yagi let's say, just as an example, that you were optimizing on variables B/D/E. Now you want to *also* optimize on the middle element boom position so you use a new variable, let's say G.

    You return to the optimizer tab, but notice that the list of "Variables to be Adjusted" as shown in row 15 still shows *only* B/D/E. To fix that, on the *Variables* tab click the "Optimizer Setup" button and select *all four* variable names. Then, and only then, go back to the Optimizer tab and click "Start".

    Remember, your model might use many different variables and the optimizer does not "know" which you want to modify. That's what the "Optimizer Setup" button is for. Very often you'll want to optimizer on only a subset of the total variables *in use* in the model.

    Edit
    The "Save Changes" button on the TempEdit tab does indeed save any changes that you might have made to the model. However, that button has nothing to do with which variables are to be optimized. Also note that it is not strictly necessary to make changes via the TempEdit tab. You can replace numbers with formulas directly on the Wires tab if you wish.

    Also, "Save Changes" only let's you decide to "keep" (as opposed to clicking "Cancel") any changes uou might have made. That's not the same as "Save Model As" which actually replaces the *.weq file. I realize now those two buttons might be confused.
    End Edit

    Dan, AC6LA
     
    Last edited: Jun 4, 2020
  6. UA3TW

    UA3TW Ham Member QRZ Page

    Dan, I mean that: in red oblong
     

    Attached Files:

  7. AC6LA

    AC6LA Ham Member QRZ Page

    I was typing an edit as you posted. See (edited) #55 above.

    Dan
     
    UA3TW likes this.
  8. UA3TW

    UA3TW Ham Member QRZ Page

    It seems I understand this at last. An example is attached - a 3el yagi without variables. Then I began to modify the model putting some variables. First I made a list of variables like this: A 4.7 Director Y; B 5 Driven el Y;
    D 5.3 Reflector Y. Then I opened the list of wires and printed =A instead of 4.7 and =-A instead of -4.7. Nothing has changed. That is the main thing that confused me. I decided that it was a wrong action, I did not realise that if I pressed "formulars" I would see the =A there. I understood this only today. Yesterday when I saw that nothing changed, I pressed "formulars" and printed =A and =-A instead of 4.7 and -4.7
    But I had to press "Save changes".
    This is not the whole story yet, but I am too tired to continue. I'll go on on Munday.
     

    Attached Files:

  9. KL7AJ

    KL7AJ XML Subscriber QRZ Page

    Center to center.....which is why, if you're not careful, you can have two parallel wires occupy the same space, which will cause a "divide by zero" error somewhere along the line.
     
  10. AC6LA

    AC6LA Ham Member QRZ Page

    So far so good. The Variables tab now looks like this:

    Vars1.png

    You did it correctly but you were mistaken about the "nothing has changed" part. On the Wires tab, when you first select cell C11 you see this:

    Vars2.png

    Note that "4.7" is shown in both the cell and in the formula bar near the top of the window.

    When you type "=A" (or "=a", both without quotes) and press Enter you will see this:

    Vars3.png

    Cell C11 now shows the value (that is, the equivalent of what you typed) whereas the actual formula that you typed is now shown in the formula bar near the top of the window. So something really did change, namely that cell C11 now contains the formula "=A" instead of the value "4.7". The subtle difference can be confusing for new Excel users.

    As described above it is not required that you click the "Formulas" button in order to enter a formula in a cell. And when you do click the "Formulas" button you will see this message, but only once per AutoEZ session.

    Vars4.png

    When making simple changes on the Wires tab I hardly ever use the "Formulas" button. For an additional example see the Quick Start Guide, Step 6 where you will find this illustration:

    [​IMG]

    ~~~~~~

    Here is another little Excel trick. Suppose you want to enter the same value (or the same formula) in multiple cells. For example, you want to change the boom position (along the X axis) for the Director from "4.5" to "4.6". You could select cell B11, type "4.6" then select cell E11 and type "4.6".

    Or, you could select cell B11, hold down the Ctrl key, then select cell E11. The two cells selected would look like this:

    Vars5.png

    Now type "4.6" then hold down Ctrl and press Enter. When you hold down Ctrl and press Enter whatever you typed will be entered in all the currently selected cells, and you selected multiple cells by holding down Ctrl when doing the selections.

    Dan, AC6LA
     

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