eddie,
where does your model indicate that current in the mast is in phase or maybe i should ask how are they showing phase?,
the way it looks to me the mast is in phase with the lower portion of monopole and out of phase with the radials and upper monopole as id expect, is there something you can alter in the settings to make phase easy to see like ezbob? if it is in phase i don't get it and i want to understand whats going on
Yep, I think you're right again Bob.
I re-read the manual on currents and noticed some better information in the form of a caution, not to depend on the Antenna View of the antenna showing currents, because the software uses smoothing routines to make the images look better. Manual says to use the tabular data report under the tab in Eznec noted as "Currents." I sent that to you Bob in a PDF file and that is the same one I posted on this thread.
Since we can't edit our own stuff after some time anymore, I guess the PDF file of my model output will have to stay there...in error.
After checking my model, which you made me do, I found the error I think that produced the model's information that I was going over with Shockwave earlier...about the currents right below the antenna on the mast being in-phase.
I'm sure my model is wrong. Thanks to your determination Bob, I think I have corrected the problem and I've learned another important factor in modeling today. The factor was so important that Roy L wrote a warning about the issue.
When I re-built this model from Henry, I was determined to get the measurements as correct as I could and then only to fix the tip of the antenna trying to get the model resonant if necessary. I was not planning to tweak it otherwise. But as usual, I wanted to see if I could get the resistance closer to 50 ohms, and I did. I started changing Henry's source location for the model, which was at 0* degrees from the base, and noted that the resistance showed to be getting better. So, I pushed the source right to the end of wire #2, the base wire of the antenna where the gamma goes. This would be the tap point par-se. I knew it was in the wrong place, but the resistance moved much closer toward 50 ohms and that was good, so I left it alone. I know better now.
Bob, I put the source back to approximately 33" high on wire #2 and I ran the pattern and gain reports. The gain improved a bit from 4.7dbi @ 7* degrees to 4.89dbi @ 7* degrees. That didn't hurt a thing and it wasn't off the wall high or low and the pattern was not affected. I see this with other adjustments too, the pattern is not easy to wreck.
Then I checked the tabular record for the Currents and wa-la'---the in-phase condition below the antenna no longer showed to be in-phase with the radials, etc., just as you complained it should be.
My model now agrees with EzBob. I had the source located at 99% from end2 of wire #2 (#2=71.5") and it should have been at 45.99% which equals 33" up from the base. 71.5" x .4599% = 32.88" I think we can see the big red circle high up on the first radiator portion inside the radials.
I still have to undo the .5" adjustment I made to the radial length, because I think I was in error on that one too. I will have to check the manual closer and try to figure out exactly how long the radials are and on the radials where to attach the hoop. I discovered today that the hoop is set back by .5" from the top of the radials, so that will make a little difference, and I want to get it right in case the difference is significant to the results.
When I finish guys, I will repost the model output like before, so y'all can check me out. You see how my friend Bob did me a favor by questioning me on something that he didn't feel was right. If this effort is better for accuracy then I consider Bob did me a favor, and I learned an important aspect about the software 2-boot.
So don't get your dander up in a huff and a puff, when someone asks you a question. And, don't be afraid to ask your questions either. That is how we learn HomerBB.
