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Re: [TowerTalk] RF current in REF + DIR ..how much ?

To: Tower Talk List <towertalk@contesting.com>
Subject: Re: [TowerTalk] RF current in REF + DIR ..how much ?
From: Kevin Normoyle <knormoyle@surfnetusa.com>
Date: Wed, 22 Dec 2010 18:28:43 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 12/22/2010 5:46 PM, Al Williams wrote:
> I am surprised that YO or 4nec2 don't include actual current measurement
> in the parasitic elements.

4nec2 includes the nec2 output file with numbers if you want them.
I use File/Save Nec output file, then look at the file (after a calculate)

If you specify the voltage magnitude correctly on your input deck (assuming 
that's how you drive the thing)..the numbers in the output are correct amps, 
aren't they?

i.e. it looks like this. (these segs are tips..low current0

- - - CURRENTS AND LOCATION - - -

                                  DISTANCES IN WAVELENGTHS


   SEG.  TAG    COORD. OF SEG. CENTER     SEG.            - - - CURRENT (AMPS) 
- - -
   NO.   NO.     X        Y        Z      LENGTH     REAL        IMAG.       
MAG.        PHASE
      1    1  -0.2336  -0.0118   1.0088  0.01168   3.4782E-01  3.1149E-01  
4.6691E-01   41.845
      2    1  -0.2220  -0.0118   1.0088  0.01168   8.6683E-01  7.7849E-01  
1.1651E+00   41.927
      3    1  -0.2103  -0.0118   1.0088  0.01168   1.3280E+00  1.1962E+00  
1.7873E+00   42.010
      4    1  -0.1986  -0.0118   1.0088  0.01168   1.7632E+00  1.5929E+00  
2.3762E+00   42.095

4nec2x also can generate plots of current mag/phase/real/img (from the 
Geometry/plot). Those currents seem to track the "input power" setting. I'm not 
sure how they are connected to the nec2 output file.

as a for instance:
for example, a 3 element 20 at 70', Zl=25, 1" Al, with an LC match
the plot shows  current magnitudes: (max at center). 1500w input power
7.6 for the de
4.5  for the dir
3.1 for the ref

relatively, those numbers seem right. Absolute, maybe seems high..Not sure.
That doesn't seem to track changes to the voltage magnitude I use in the input, 
but the nec2 output file does track the voltage magnitude I use on the input.

-kevin
ad6z

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