[TowerTalk] Antenna Modeling

[Bruce Jungwirth]

Thanks Jim. I’ll look at your pdf’s. Actually I would like to learn EZNEC, but for now I’m looking at two similar antennas. Both would be 210 ft , center fed with ladder line to a balun then ~25 ft of LMR400 to a Ten-Tec 238 tuner. One antenna uses any convenient length, (min 40 ft) of 450 ohm Ladder line to a 4:1 balun. The other is the DX Engineering DXE-WA-260 160-10 Meters Multi- Band Dipole kit. They recommend using 60.1ft, or odd multiple there of, of 300ohm ladder line to a 1:1 balun. I know both will be NVIS, I’m just trying to determine which would be the better choice. 

Sent from my iPad

> On Jul 11, 2018, at 2:12 PM, Jim Brown <jim at audiosystemsgroup.com> wrote:
> 
>> On 7/11/2018 10:52 AM, Bruce Jungwirth wrote:
>> I’m looking for someone in or around St Paul Mn that is fluent in EZNEC.
> 
> A principal value of EZNEC and other modeling software is as a teaching tool, and you only learn from it when YOU do it. It's not all that difficult to learn once you get over the fear factor. The free version that comes with the ARRL Antenna Book will model simple antennas like you're thinking about.
> 
> Here are several studies I've done to help think about problems like yours.
> 
> http://k9yc.com/VertOrHorizontal-Slides.pdf
> 
> http://k9yc.com/VerticalHeight.pdf
> 
> http://k9yc.com/43FtVertical.pdf
> 
> http://k9yc.com/AntennaPlanning.pdf
> 
> I am a big fan of fan dipoles. A good rule is to not try to put more than three elements in the fan.  80/40 makes a good fan, so does 20/15/10. Although I haven't done it, i suspect that 30/17 would too.
> 
> 73, Jim K9YC
> 
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