[Antennaware] model sources

[Paul Decker]

Hi Guy, 



Thanks for the reply.  Yes, that makes sense, often I had not made models with multiple feedpoints so I didn't notice a difference between I/V.  In many cases I was using SI/SV at non wire junctions, but that didn't seem to make a difference either.   I do see a difference when switching between I/SI and V/SV at a wire junction. 



I won't take your rtfm as a blow off, although i did read the manual some years ago.  I have either forgetten what I knew, or didn't think I understood it enough.   I'll check again and see if it makes sense.   When you say "two feedlines connected in parallel, do you mean for example a slitter which acts as a phasing array?" 



thanks, 

Paul 

----- Original Message ----- 
From: "Guy Olinger K2AV" <olinger at bellsouth.net> 
To: "Paul Decker" <kg7hf at comcast.net> 
Cc: antennaware at contesting.com 
Sent: Tuesday, March 2, 2010 12:46:04 PM GMT -05:00 US/Canada Eastern 
Subject: Re: [Antennaware] model sources 

If you have a single feed point, I or V is immaterial. SI or SV is 
used put a feedpoint at a wire junction, as in a Vee antenna. Mark the 
two connected points as SI or SV. 

When you have more than two feedpoints in a model you now have to 
decide whether you will drive them with forced voltage (two feedlines 
connected in parallel) or forced current (various devices) and set 
their phases. That's where the I and the V come in.   By far the most 
concise discussion around on these is to be found in the EZNEC help 
screens.  This is not a put-off of any kind as in RTFM, it is a 
sincere recommendation to probably the very best first reference 
source. And it is indexed and searchable. 

73, Guy. 

On Tue, Mar 2, 2010 at 8:11 AM, Paul Decker <kg7hf at comcast.net> wrote: 
> 
> 
> Hi group, 
> 
> 
> 
> I use EZ-NEC 5.0, but I'm wondering what the different sources mean and when they should be used.  For example there is a selection for I, V, SI and SV .   Over the past few years I have been using them mostly interchangeably without seeing any differences in the the results.   Now I have built a model where I see dramatic difference between using I sources vs. using V sources, so I'm interested in what the different sources mean. 
> 
> 
> 
> thanks and 73, 
> Paul (KG7HF) 
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