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#21
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Roger wrote:
Congratulations on a clever use of zero resistance loads. I am probably missing something, but why not just show the currents and phase in the 'View Antenna' window ? |
#22
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4nec2 wrote:
Roger wrote: Congratulations on a clever use of zero resistance loads. I am probably missing something, but why not just show the currents and phase in the 'View Antenna' window ? Maybe I am missing something. I can not get a numeric record of the phase and current in the "View Antenna" window. I am using version 4.0. |
#23
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4nec2 wrote:
Roger wrote: Congratulations on a clever use of zero resistance loads. I am probably missing something, but why not just show the currents and phase in the 'View Antenna' window ? For current phase, EZNEC does not display the same absolute phase as the "Load Dat" function reports. That would appear to be a bug in the EZNEC GUI software. I'm glad you asked that question. Perhaps W7EL can tell us why EZNEC does not display the same current phase as it reports in the "Load Dat" function. EZNEC seems to display the current amplitude correctly but it is unclear exactly what EZNEC is displaying when the current phase box is selected. That's why I used the "Load Dat" feature. Here is a graphic using the "View Antenna" window for the EZNEC files TravWave.EZ and StndWave.EZ. http://www.w5dxp.com/eznec.jpg Looking at TravWave.EZ with the current phase turned off, the current displayed is indeed the amplitude of the current up and down the wire which is essentially a constant RMS magnitude. But with the current phase turned on, the display does not display the same phase reported by "Load Dat". It displays a cosine function when the actual phase function is a straight sloping line varying from 0 degrees at the feedpoint to -90 degrees at the load resistor. What EZNEC is actually displaying associated with phase is unclear, confusing, and misleading. StndWave.EZ has the same unclear display for phase. The current amplitude is the correct cosine function but the current phase is misleading. The "Loads Dat" function says the phase varies from 0 degrees at the feedpoint to -0.11 deg at the open end of the wire, i.e. virtually no change at all in phase up and down the wire. Yet EZNEC displays a cosine function for the current phase the meaning of which is unclear. To answer your question, EZNEC does not display phase when the current phase box is selected. It is unclear to me exactly what EZNEC is displaying when the current phase box is selected. -- 73, Cecil http://www.w5dxp.com |
#24
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Roger wrote:
Maybe I am missing something. I can not get a numeric record of the phase and current in the "View Antenna" window. I am using version 4.0. You do get a *graphic* record of the current amplitude in the "View Antenna" window. It is unclear exactly what is displayed when the current phase box is selected. You do NOT get a numeric record in the View Antenna window. For a numeric record, you must use the "Loads" and "Load Dat" feature. -- 73, Cecil http://www.w5dxp.com |
#25
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Cecil Moore wrote:
Here is a graphic using the "View Antenna" window for the EZNEC files TravWave.EZ and StndWave.EZ. http://www.w5dxp.com/eznec.jpg Sorry, the graphic only contains information about TravWave.EZ Looking at TravWave.EZ with the current phase turned off, the current displayed is indeed the amplitude of the current up and down the wire which is essentially a constant RMS magnitude. But with the current phase turned on, the display does not display the same phase reported by "Load Dat". It displays a cosine function when the actual phase function is a straight sloping line varying from 0 degrees at the feedpoint to -90 degrees at the load resistor. What EZNEC is actually displaying associated with phase is unclear, confusing, and misleading. StndWave.EZ ... Please ignore what I said about StndWave.EZ To answer your question, EZNEC does not display phase when the current phase box is selected. To be more clear. EZNEC does not display the same phase as reported by the "Loads" feature. -- 73, Cecil http://www.w5dxp.com |
#26
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Roger wrote:
4nec2 wrote: Roger wrote: Congratulations on a clever use of zero resistance loads. I am probably missing something, but why not just show the currents and phase in the 'View Antenna' window ? Maybe I am missing something. I can not get a numeric record of the phase and current in the "View Antenna" window. I am using version 4.0. In all versions, the View Antenna display shows the currents only graphically and not numerically. There are three ways to find the numerical value of current at a particular segment: 1. Click the Currents button at the left of the main window. This gives the currents at all segments. 2. Insert a zero ohm load at the segment of interest and click Load Dat to see its current. 3. Insert a zero volt voltage (not current) source at the segment of interest and click Src Dat to see its current. Roy Lewallen, W7EL |
#27
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Roy Lewallen wrote:
1. Click the Currents button at the left of the main window. This gives the currents at all segments. 2. Insert a zero ohm load at the segment of interest and click Load Dat to see its current. Why doesn't EZNEC accurately plot those currents on the antenna display? -- 73, Cecil http://www.w5dxp.com |
#28
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On Thu, 20 Dec 2007 15:04:36 -0600, Cecil Moore
wrote: accurately And this cry in the wilderness from someone who can prove fundamental principles with +/-40% error. ;-) |
#29
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Cecil Moore wrote:
Roger wrote: Maybe I am missing something. I can not get a numeric record of the phase and current in the "View Antenna" window. I am using version 4.0. You do get a *graphic* record of the current amplitude in the "View Antenna" window. It is unclear exactly what is displayed when the current phase box is selected. Although one can get a current amplitude plot vs length from EZNEC, it seems impossible to get a current phase plot vs length. That's probably why so many people are confused. Click on "Currents" and transfer that data to EXCEL to make things a lot clearer. -- 73, Cecil http://www.w5dxp.com |
#30
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Cecil Moore wrote:
Cecil Moore wrote: Here is a graphic using the "View Antenna" window for the EZNEC files TravWave.EZ and StndWave.EZ. http://www.w5dxp.com/eznec.jpg Sorry, the graphic only contains information about TravWave.EZ Looking at TravWave.EZ with the current phase turned off, the current displayed is indeed the amplitude of the current up and down the wire which is essentially a constant RMS magnitude. But with the current phase turned on, the display does not display the same phase reported by "Load Dat". It displays a cosine function when the actual phase function is a straight sloping line varying from 0 degrees at the feedpoint to -90 degrees at the load resistor. What EZNEC is actually displaying associated with phase is unclear, confusing, and misleading. StndWave.EZ ... Please ignore what I said about StndWave.EZ To answer your question, EZNEC does not display phase when the current phase box is selected. To be more clear. EZNEC does not display the same phase as reported by the "Loads" feature. Cecil, I presume that this is a silly question, but "Did you read the manual"? EZNEC is displays the current phase exactly as described in the manual. Hint: Current is shown as distance from the axis. Current PHASE is shown by a rotation around the axis, not by the distance from the axis. 73, Gene W4SZ |
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