[Antennaware] plot comparisons

Terry Conboy n6ry at arrl.net
Fri Nov 13 10:41:17 PST 2009

I tried Gary's approach of using an external graphic program with the 
simple "Paint" program that is included in Win XP.  From the 2D plot 
window in EZNEC, I used Edit - Copy Plot, then pasted the plot image 
into Paint.  Then I opened the second antenna file, ran FF Plot and 
repeated Edit - Copy Plot and pasted the second image directly on top of 
the first plot in Paint.  If you uncheck the Image - Draw Opaque option, 
you will see the two plots overlaid on each other with the same max 
relative gain.  If you want, you can then do File - Save As in your 
choice of graphic format.  (A .gif works pretty well for line plots like 

73, Terry N6RY

On 2009-11-13 7:27 AM, K9AY wrote:
> Dave and all,
> To quote from W7EL's Help File:
> "Note that .pf format files saved as 'trace files' are not graphics files. 
> They are binary files which contain only numerical field strength data, and 
> no information about how to plot or display it."
> Thus, gain is part of the saved data in EZNEC and overlaid plots within 
> EZNEC will always be displayed with that gain difference.
> To do what you want, you'll need to do the multi-plot overlay outside of 
> EZNEC, in a graphics program. With the default 'Automatic' setting in Desc 
> Options, all exported plots will have max. gain at the outer ring. If you 
> want to maintain the gain difference, it's necessary to set the outer ring 
> to a fixed value for all plots to be exported.
> Gary
> K9AY
>> Thanks to all who have replied.
>> I must apologise for the mess I made of asking the question, looking
>> back I did not make myself at all clear, and congratulation to Terry
>> for seeing through the confusion and picking up correctly on what I
>> was trying to ask.
>> His last paragraph, below, sums up perfectly what I am trying to
>> achieve. It is an electronic version of printing off the two
>> individual plots onto clear actetate and then overlaying them
>> physically, in which case the gains of the outer rings will be different.
>> 73,
>> Dave, G3UEG
>> At 00:36 13/11/2009, Terry Conboy wrote:
>>> When I overlay the elevation plot for a 4 square array on top of the
>>> plot of single vertical, the plot for the single vertical is ~5 dB down
>> >from the 4 sq.  I tried setting the reference gain for the outer ring of
>>> the plot to a fixed higher value (in Desc Options) before saving the
>>> plot to shrink it, but the program still displays the higher gain
>>> antenna plot larger than the lower gain antenna by the ratio of the
>>> gains when overlaid.  I see Dave's dilemma.
>>> Perhaps Gary has an option set that I have missed to allow the maxima of
>>> the plots to be coincident, even though the absolute gains differ.
>>> 73, Terry N6RY
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