Tuesday, 6 March 2012

Using MMANA-GAL for antenna modelling


I gave a talk on antenna modelling using the free MMANA-GAL software at my local Amateur Radio Club. It looks at what MMANA-GAL is, how to use it and then a number of different applications.

Some of these are useful and surprising - like how to optimise a 40m off centre fed dipole (Windom) so that you can get 15m. And how mounting an antenna as an inverted V can seriously change its radation pattern or number of bands available.

It also asks the question is the G5RV really a good multiband antenna? Why was my W3EDP end fed better to the south-east and south west and rotten to the north. And does the DL7PE Microvert radiate off its feeder?

Download the presentation in PDF format with the notes included (8.8Mb).

Note: I have also made available a Zip file with some .maa files including the End fed Half Wave, Rybakov vertical, DL7PE Microvert, 80cm magnetic loop, 65ft Inverted L, EH antenna, 20-15-10m trap dipole, 80m OCFD (Windom) and an experimental W5GI mystery antenna file. Download the MMANA-GAL antenna files.

7 comments:

  1. Did you happen to record your presentation, either audio or video? Might be instructive listening.

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  2. tnx steve .... i try learn this program but i have alot of question and no more video on youtube.com but all the ways i tnx you so much for your great effort

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  3. how can you do a round mag loop ?

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    1. Hi Marko,

      The usual way is to produce an eight-sided octagonal loop. I think there is an 80cm diameter one in the examples with MMANA-GAL. If not, use the following definition:

      MagLoop 20m, 50 Ohm feed
      *
      14.05
      ***Wires***
      16
      0.08, 0.03, 0.0, 0.08, -0.03, 0.0, 0.005, -1
      0.08, -0.03, 0.0, 0.11, -0.06, 0.0, 0.005, -1
      0.11, -0.06, 0.0, 0.17, -0.06, 0.0, 0.005, -1
      0.17, -0.06, 0.0, 0.2, -0.03, 0.0, 0.005, -1
      0.2, -0.03, 0.0, 0.2, 0.03, 0.0, 0.005, -1
      0.2, 0.03, 0.0, 0.17, 0.06, 0.0, 0.005, -1
      0.17, 0.06, 0.0, 0.11, 0.06, 0.0, 0.005, -1
      0.11, 0.06, 0.0, 0.08, 0.03, 0.0, 0.005, -1
      0.0, 0.15, 0.0, 0.0, -0.15, 0.0, 0.01, -1
      0.0, -0.15, 0.0, 0.3, -0.45, 0.0, 0.01, -1
      0.3, -0.45, 0.0, 0.6, -0.45, 0.0, 0.01, -1
      0.6, -0.45, 0.0, 0.9, -0.15, 0.0, 0.01, -1
      0.9, -0.15, 0.0, 0.9, 0.15, 0.0, 0.01, -1
      0.9, 0.15, 0.0, 0.6, 0.45, 0.0, 0.01, -1
      0.6, 0.45, 0.0, 0.3, 0.45, 0.0, 0.01, -1
      0.3, 0.45, 0.0, 0.0, 0.15, 0.0, 0.01, -1
      ***Source***
      1, 0
      w1c, 0.0, 1.0
      ***Load***
      1, 1
      w13c, 0, 0.0, 53.672, 0.0
      ***Segmentation***
      800, 80, 2.0, 2
      ***G/H/M/R/AzEl/X***
      0, 17.0, 4, 50.0, 120, 60, 0.0

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  4. Hi,Steve!
    More than writing a comment, may I ask your help in plotting using mmana-gal wire antennas with antenna coupler. I use an SGC-230 with the loop antennas suggested by SGC in http://www.sgcworld.com/Publications/Books/stealthbook.pdf pages 23-24. I would like to see how the patterns vary across the bands. Any help would be appreciated. Thanks!

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    1. Hi, from what I can see this is a coiled, loaded wire arranged in a square. This would be very hard to model in MMANA-GAL as you can only model straight wires, and add capacitors and inductors. While it is easy to model wire it is not easy to model such an arrangement.

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