[Antennaware] Re: Returned mail: User unknown

[K7GCO@aol.com]

In a message dated 6/5/2002 2:49:36 PM Pacific Daylight Time, 
btippett@alum.mit.edu writes:
> K2HK wrote:
> >I am attempting to model a CC X9 tribander which has trapped directors and 
> 
> log cell feed. Has anyone done this? It is a formidable project for an 
> inexperienced modeler.
>         This TH-6DXX model by K9UWA is the closest thing I've seen to
> what you want:
> http://www.kkn.net/~k5tr/th6ao.ant
> It is a K6STI AO model so it's based on Mini-NEC.  K6STI's YO programs 
> (NEC-2 equivalent) also have models for KLM log-cell feed Yagi's but
> I agree with other comments that this is not a trivial task for
> an inexperienced modeler. 
>                                                 73,  Bill  W4ZV 
> I don't think it can be done as you would have to know the "exact" 
> inductance of each inductor and the capacitance of each capacitor or 
> whatever form is used to insert into the software.  A slight error will 
> detune the antenna.  I'd live with would you got unless someone has 
> stumbled on to a change for the better.  Erect another tower and build a 
> yagi or quad and play games with that.  You really can't do much even with 
> that unless you can use the antenna software.  You will have to bite the 
> bullet and have someone teach you how to enter antenna dimensions into it 
> in the XYZ coordinates.  I've spent thousand of hours on Eznec and I 
> wouldn't even attempt to model a trapped beam.  
>      I have spent many hours with a 6 band 2 element quad on tapered arms 
> with great results.  It reproduces.  I also found that the individual 
> patterns of each band ended up better for gain and F/B that possible for a 
> mono bander.  This was effort well spent but took a lot of experience and 
> time to do.  Several wise one told me this wasn't true without even trying 
> it as if it was illegal if they didn't believe it.  Cebic verified it and I 
> saw his data also.
>     Unless you know what changes to make, leave a commercial antenna alone. 
>  Most are well designed.  Asking others to do a big job free even with all 
> the data is not in the cards.  Learn how to use Eznec and have some fun 
> with home made beams.  k7gco


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