52 Week Ham Radio Challenge 2025 - Week 19: Simulate an antenna!

Challenge for 2025-05-05 - 2025-05-11:

Category: šŸ› ļø - Difficulty: 🟠

Simulate an antenna!
Which antenna type did you pick? Which program did you use? How does the process of entering the antenna work in that program? Which are the important parameters you get from the simulation?


Toots mentioning this challenge

DateUserUser scoreStatusToot summary & link
2025-03-19 16:22:21n8dmt@mastodon.radio20Working on it...@VE7WYC Would not be too hard to build ā€œoneā€ of those using PCV pipe with #12 copper (THNN house) wiring inside. Use radials instead of ground screen. Might be fun to simulate in the upcoming HC19 #HamChallenge ā€œsimulate an antennaā€ activity. #HamRadio
2025-03-19 16:26:21n8dmt@mastodon.radio20Working on it...@VE7WYC Would not be too hard to build ā€œoneā€ of those using PCV pipe with #12 copper (house) wiring inside. Use radials instead of ground screen. Might be fun to simulate in the upcoming HC19 #HamChallenge ā€œsimulate an antennaā€ activity. #HamRadio
2025-03-19 16:32:22n8dmt@mastodon.radio20Working on it...@VE7WYC Would not be too hard to build ā€œoneā€ of those using PVC pipe with #12 copper (house) wiring inside. Use radials instead of ground screen. Might be fun to simulate in the upcoming HC19 #HamChallenge ā€œsimulate an antennaā€ activity. #HamRadio (edited)
2025-03-27 13:59:26n8dmt@mastodon.radio20Working on it...For those interested in antenna modeling/simulations and/or working #HamChallenge HC19 @hamchallenge, but concerned about the complexity of these activities, I would like to share the easiest-to-use (free) program I’ve found so far: AN-SOF. Have SW loaded on my ham Win11 machine and ready to explore capabilities/limitations of this package.Here’s a 20m dipole example walk-through that gives good insight into this SW:https://antennasimulator.com/index.php/knowledge-base/complete-workflow-modeling
2025-04-06 16:15:53n8dmt@mastodon.radio20Working on it...HC19 Had a chance to try out free AN-SOF antenna simulation SW while modeling a vertical over ground plane and a free-space dipole. Both models worked out well and confirmed 1) SW works as advertised, and 2) have not forgotten everything learned in the past about antenna modeling. Plan is to put together a write-up/posting on my QSL.net/n8dmt web page after copying over screen captures from my Win11 ham computer. SW is reasonably easy to use (with a little guidance). #HamRadio
2025-04-06 21:51:28n8dmt@mastodon.radio20Success!HC19S Put together a quick post on how to create a simple 10m half wave dipole antenna simulation in AN-SOF (free trial SW) on my Win11 ham PC. https://qsl.net/n8dmt/an-sof-simulation-of-a-10m-free-space-dipole/index.htmlWill work on a 1/4 wave vertical over ground plane simulation next. 73#HamRadio
2025-05-08 14:04:58ei7ijb@mastodon.radio6Working on it...For the 19th challenge, 'Simulate an antenna!’, I have few points to review and decide. E.g. ā€˜Is there a software that can run on a Mac or do I need to look for a Windows version?’, ā€˜Can I model an EFHW and how will that help with an EFHW setup at my QTH?’, ā€˜Do I start with the bands that I want to get on the air like 40m, 30m or 10m?’, ā€˜Do I just start simple and build from there?’, etc. First step is to find the software. #hamchallenge HC19 @hamchallenge
2025-05-10 17:15:27ian@mastodon.radio18Success!This week on the Ham Challenge, I have been trying my hand at antenna modelling. I am at least 10% sure I know what I'm doing here...#HamChallenge HC19S
2025-05-12 21:16:44DJ5CW@social.darc.de17Success!@g7kse A quick simulation with CST of a quarter-wave vertical over a ground plane. Diameter 1mm, length 81mm, resonance at 875 MHz. Added an ABS (er = 3) cylinder 0.5mm wall thickness, with diameter 2mm: 852 MHz, i.e. about 20 MHz drop. Edit: HC19S @hamchallenge
2025-05-15 22:03:47yo3gnd@mastodon.radio30Working on it...@n8dmt oh whoops. that explains yesterday too! one #hc19s please!
2025-05-16 09:07:53yo3gnd@mastodon.radio30Working on it...Hey @hamchallenge, update on yesterday's #hc19s #hamchallenge didn't quite make it?
2025-05-16 10:58:04yo3gnd@mastodon.radio30Success!Fine. really wants the rest of the simulations for #HC19S 6/xSetup 2 is just like Setup 1, except the radiator is now straight. So we have:- Uneven radials, varying between 80 and 120% of the length I use- the radials cover only 270° and have variations of a few degrees from their ideal locationI'm omitting the donut here and posting a comparative view with setup 1 (red) vs this one (blue)Z = 56.2 - j8.45ΩSWR 1.22 @ 50Ω 14.13 MHzRadiation eff 24.02%
2025-05-16 11:02:04yo3gnd@mastodon.radio30Success!Fine. really wants the rest of the simulations for #HC19S 6/xSetup 2 is just like Setup 1, except the radiator is now straight. So we have:- Uneven radials, varying between 80 and 120% of the length I use- the radials cover only 270° and have variations of a few degrees from their ideal locationI'm omitting the donut here and posting a comparative view with setup 1 (red) vs this one (blue)Z = 56.2 - j8.45ΩSWR 1.22 @ 50Ω 14.13 MHzRadiation eff 24.02%
2025-05-16 11:13:05yo3gnd@mastodon.radio30Success!7/x Setup 3: radials are evenly spaced, uneven length (the spacing gap is around the coax in the field)#hamchallenge #HC19S Z = 56 - j10.8ΩSWR 1.26 @ 50Ω 14.13 MHzRad eff 24.06%Concluding this series of 4 sims:- each step closer to ideal helps a tiny amount: better match, lower SWR, deeper null, symmetric lobes- The compromised version seems fine for /P, since all these optimizations take time on the field and seem worthless, especially for time constrained operations.

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