Software-defined Antenna Analyzer

  • 6
  • Idea
  • Updated 3 years ago
  • Under Consideration
Been doing a lot of antenna work lately and found myself taking SWR readings at lowest power level across different bands and manually recording actual SWR ranges.  I could use my antenna analyzer, except I'm several hundred miles away and it's a slow, arduous process even if I were physically present.

This gave me an idea... what if the Software-Defined Radio could be used as an antenna analyzer? The SDR could sweep across the bands, taking antenna analytics readings and producing charts for each band.  Perhaps pressing a button would analyze the current band (slice) or using a form one could select multiple bands or a frequency range to analyze.

Of course we can use an expensive instrument to accomplish this antenna analysis job, but typically they're expensive and have various limitations, like the display or frequency range.

If this feature were available, I would use it periodically when doing new antenna testing and development, as well as to take a "baseline" measurement, then go back to verify things haven't drifted out of alignment over time.

I would even consider paying $100 to $200 for this as an add-on module, if not provided built into SmartSDR.

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Rick - W5FCX

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Posted 3 years ago

  • 6
Photo of KM4CQG


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Morning Rick

Been there done that take a look at this page download SWR Plotter.

Prepare to be amazed .

Its great when your radio is hooked up but if your up the tower you need the hand analyzer make no mistake nothing like tunning the antenna while using the Analyzer.

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Lawrence Gray

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I love SWRPlotter and use it regularly.  Additional functionality would be nice, but it works very well and is helpful with my antenna projects.
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Bob Hawkins

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Love this idea! It makes complete sense.
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this was made in the ols day by Kachina 505dsp that i had great tool for sure 
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Bill W2PKY

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See this website:; The 6K will only report SWR inside ham bands.
I recently purchased an AA-54 which can report SWR on any frequency in the HF + 6M spectrum.
This device has the added convenience of portable "in the field" measurements.
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EA4GLI - 8P9EH - Salvador

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I was going to post the same link to
Great stuff from Ray K9DUR 
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EA4GLI - 8P9EH - Salvador

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Additionally, for the tinker inside all of us.....
You can go to the AppData folder of SWRPlotter (C:\Users\YOURUSER\AppData\Roaming\RNA Software\SWRplotter6k)  and modify the BandLimits.xml file that SWRPlotter opens to "widen" the range and plot SWR outside of the band limits.

If we could get SWR readings from the XVTR port of the Flex radio you could do some fancy plots of SWR.
And if you could use the RX port and XVTR ports you could even get to have a Vector Network Analyzer inside the radio.... but that is just dreaming.... In the meantime I got myself a MetroVNA.
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Tim - W4TME, Customer Experience Manager

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This is already in our feature database as item #4058.
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Ken - NM9P

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Not only basic SWR charting, but more elaborate Vector Network Analyzer function have been talked about off and on since the early days of SSDR on several threads.  This is one of the earlier ones:

There are others:

There may be some interesting possibilities, using the XVTR port and extremely low power.  I would classify this as a "dreaming/brainstorming" idea at present.  I suspect any real experimentation will be a long way off...after  

But I would love to be proven incorrect!

Ken - NM9P
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Rick - W5FCX

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Yes, SWR Plotter 6K worked like a champ!

Thank you!