Hey, Jonathan, That is exactly how you are to do it. One point though, you do not have to specify the exact segment to place it. Just give the LOAD window a "percentage from the end" and it will place it close enough. However, If you do have the 500 segment version you can place it exactly where you wish by using many segments to define the element.
Definitions and How To's --- In EZNEC, go to Help/Contents and click on LOADS / RLC and LOADING COILS and also TRAPS. There are good explanations of each implementation and probably more detail than you want if you follow all of the subsequent links. GL and 73...rick <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Wed, Dec 2, 2020 at 10:13 AM Jonathan Guthrie via BVARC <[email protected]> wrote: > I got a question about analyzing antennas with traps and loading. > > If you're familiar with the book "The Short Vertical Antenna and Ground > Radial" by Sevick, I simulated one of the antennas he wrote about in an > NEC2 system and I think I got it right, but the way that you put traps and > loading coils and such into NEC is not well described anywhere that I could > find, nor are there many examples with simple antennas that have any > loading coils. If you're not familiar with the book, or you're interested > in which antenna, Sevick describes a 40m antenna that's right at 6 feet > tall with a cap hat on the top and a loading coil in the middle. The way I > modeled this is by having a single wire from near the ground to the top of > the antenna and then one wire for each of the eight spreaders in the cap > hat and a wire between each of the ends of the spreader. I arranged the > elements such that the coil is near the center of one of the segments in > the vertical wire and I put a lumped inductance on that segment. It seems > to work, in that I got SWR curves that are similar to what's in the book, > but is that how you're supposed to do it? > > Similarly, with a trap dipole, I just have one wire and put an appropriate > capacitor and inductor in parallel at the center of the desired segments. > On 12/1/2020 8:35 PM, Rick Hiller via BVARC wrote: > > Comments on your suggestions: Sorry for the length. > > *MiniNEC, EZNEC, 4NEC2, MMANA-GA*L are all based on the NEC computation > engine. What differs is the interface to you, the user. I prefer EZNEC > but then I have been using it for about 20 years. > > Cost for the Ham Radio level versions: EZNEC DEMO is free but with > severe limitations for all but very simple antennas. $99 gets you to a > quite useable version. 4NEC2 is totally free. MiniNEC is $29. MMANA-GAL > is 139 Euro's, There are PRO versions and interface add-ons from various > 3rd parties for most of the modeling engines. Just like my comment about > the Nano VNA, in that it's gonna take some time to understand its' use and > even more time to study antenna systems to understand what you are doing > and why and how -- same goes for modeling software. But....certainly all > in good fun and ham education and well worth the journey. > > *Folded dipoles a*re simply a way to get a match to 300 ohm TL. No > advantage in gain , etc. Maybe slightly quieter on receive...maybe. > TTFD is a different fish. > > *Books: *ARRL Antenna Handbook is certainly the antenna builders/users > bible. You can however buy the Kindle version of each of the separated > set books, so you don't have to spend the $60. Most of the theory is the > same in these new editions versus going back to the 70's and before. The > practical side of antennas with new materials, etc. is what gets upgraded > with each new edition. Old versions of the ARRL antenna manual can be had > for $10 typically. You can't go wrong buying any older version. > > If I had to steer you to books to read to get you up to speed about your > total antenna system -- ATU, TL, tools, and grounding, I would tell you to > get the following ARRL Joel Hallas and Ward Silver books: > The Care and Feeding of Transmission Lines -- Hallas > Understanding your Antenna Analyzer -- Hallas > ARRL Guide to Antenna Tuners -- Hallas > Grounding and Bonding for the Radio Amateur -- Silver > > I'd tell you to read and understand these before jumping into a NanoVNA, > of which there is also a small book on the use of the NanoVNA. Kindle > version available for $4 or thereabouts. > > Sorry for the bandwidth, but I don't agree with just buying something just > because it is suggested. There is alot to learn in Amateur Radio and it > is certainly fun to have a continual information influx throughout the life > of your Ham Radio journey. But watching the $'s helps you buy bigger toys > later on. > > GL ES 73....Rick -- W5RH > > > > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> > Virus-free. > www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> > > On Tue, Dec 1, 2020 at 1:16 PM KJ Anderson via BVARC <[email protected]> > wrote: > >> >> - MiniNEC pro analyzer >> - >> >> http://www.blackcatsystems.com/software/mininec-antenna-analysis-modeling-software.html >> - DX Commander >> - https://www.m0mcx.co.uk/ >> - Folded dipoles (couldn’t google a site reference other than the >> actual antenna form) >> - EZNEC >> - https://www.eznec.com/ >> - There’s a free version >> - ARRL Antenna Physics >> - >> http://www.arrl.org/shop/Antenna-Physics-An-Introduction-2nd-Edition/ >> - http://www.arrl.org/shop/ARRL-Antenna-Book-Boxed-Set/ >> >> >> >> *-------------------------------------------------* >> >> *KJ Anderson* >> >> 253-380-2636 >> >> www.linkedin.com/in/scrumnerd >> >> >> >> >> ________________________________________________ >> Brazos Valley Amateur Radio Club >> >> BVARC mailing list >> [email protected] >> http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org >> > > > -- > Rick Hiller > *e-mail: [email protected] <[email protected]>* > *Cell: 832-474-3713* > *Physical: 9031 Troulon Drive* > * Houston, TX 77036* > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing > [email protected]http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > -- Rick Hiller *e-mail: [email protected] <[email protected]>* *Cell: 832-474-3713* *Physical: 9031 Troulon Drive* * Houston, TX 77036*
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