Making Antennas

Has anyone experimented with Pothos and getting a lime to measure the VSWR of an antenna?
i.e. using the Lime to generate the noise on a Tx pin and measuring the response across a return-loss bridge?

There has been talk about using the “Ham It Up!” noise converter and an RTL dongle… so I assume it’s possible here using the lime to generate noise…

I take it you’ve also seen:

I hadn’t until now… Haven’t even had the board running a whole week yet. Was really hoping it’d be possible without a coupler - but hey, that’s life.

Super useful. Thanks @andrewback!

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Hey Guys,

After over a week, with some software setting changes, different driver and new line to the antenna, I can get pretty good reception with Gqrx. Thanks to people in this forum. Several of the points were not listed in documentation I could find.

So the next step is finding out what’s the best for trancieving. I’m particularly interested in using LimeSDR as a wide band combo spectrum analyzer and signal generator, for lab testing not related to communications. Though it would be cool to use Lime for developing more ham skills.

What apps are there for creating different waveforms? Sine, square, triangle, etc?

In looking through the forum, it looks like there was some debate about what was good for this, with some programs working then not working, over the course of some months.

I tried to get the Qspectrumanalyser running, but it didn’t want to work. It doesn’t recognize the Lime at all.

Thanks guys!

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@fltech - Daniel,

If QTSpectrumAnalyzer isn’t working and it does not see your Lime, then there’s a pretty good chance that this is because the driver you have installed won’t operate for that app. If you’re using Windows and If I miss my guess, I would think that QTSpectrumAnalyzer uses the Cypress driver that loads auto-magically from Microsoft because it’s the ‘Signed Driver’ for LimeSDR. It’s likely (I think) that if you had ZADIG running on your setup at all (for other apps) that the Cypress driver will be removed and the Win-driver from ZADIG will take its place. It’s an annoyance, but it’s the most likely cause why this is happening. If you have the Cypress driver and QTSpectrumAnalyzer is not working, then it may need the ZADIG Win-driver to make it work. Again, the annoyance with this is that you can’t have both at the same time - it’s an either/or situation with this.

Try some things and let us all know how you’re getting along, Daniel -

73 de Marty, KN0CK

ugh.

I swapped out the different drivers with zadig, but the only combination that would work was the auto magic driver from windows with Gqrx.

Now however, none of them work. I’ve gone into device manager and deleted, uninstalled, reinstalled, rebooted, etc, and even the windows “updated” driver won’t work on anything. Its windows 7 btw.

:frowning:

Hey Marty (and fellow Limers),

System restore got Gqrx working again. Just trying to fix the driver wasn’t doing anything. I work in IT, and fix computers through the week, so I’m plenty used to driver fixing. Though there’s always more to learn.

I’m wondering if Windows 8 or 10 might work better with LimeSDR. Or maybe it’s just this computer.

I’m thinking I might double or triple boot this thing to find out. Thus having 7,8 and 10 on the same computer. I haven’t done that before with 10, but i’m guessing it might work.

Also, what are the transceiver apps to work with?

Are there any other recommended spectrum analyzers or waveform/signal generator programs?

Thanks guys.

@fltech -Daniel,

I’m using Windows 10 on my LattePanda to play with SDRAngel (which uses the ZADIG application to install the WinUSB driver) for full duplex receive and transmit for Amateur Radio. It’s a wonderful app and it runs incredibly well on receive and transmit. It does have some controls that need specific adjustment, but once you get it set up and understand the controls it’s a very powerful app for transceiver operations.

I’m not as familiar with spectrum analyzer apps for the Lime but I do know that they exist. I would think that running through the threads in the MyriadRF forum would yield that info for you.

Hope this helps - 73 de Marty, KN0CK

From my experience, an app that uses the GNU Radio APIs needs to be recognised by the soapy util…

i.e. SoapySDRUtil --find=“driver=lime”
(More info: https://wiki.myriadrf.org/Lime_Suite#Device_enumeration )

Apps with native lime support through the limesuite driver (i.e. Console SDR) doesn’t seem to need soapy support. (I’ve also begun some testing with the limesuite driver as I’m really not thrilled with the usability of the limesuite utility…)

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Cool indes, I’m going to try this today. I’ve installed a bunch of SDR programs by now, and GNU ones are on there too.

Anyone know how to use a Lime as a frequency counter? I think this is what I need most, at least for the front of the process.

I’ve found mention online of people using an SDR as a frequency counter, that X or Y program could do it, but there was no explanation of how to do it.

I’d need something that can scan the whole range of MHz to lower GHz and show maybe the top 1-10 frequencies. Probably filtering by signal strength or proximity.

Is this possible with the right program or code?

Thanks guys!

Regarding antenna making…


Biconic dipole, cones IKEA original :smiley:
SWR less than 1:2 from 800 to 1500 MHz
Some more measurements =>
663 to 1865 MHz SWR is less than 2.5:1
Best SWR 1.37:1 at 1025 MHz

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:grinning: that’s cool. I’ve never seen an antenna like that before, but I’ve thought about it myself.

How well does it work? Can one be made like that from 1MHz - 3GHz?

Work like average dipole, just wide-band…
Yes can be done 1 to 3 GHz but you may have higher SWR on top end…
Cones must be smaller, no such cones in IKEA so you must order custom made
from copper or brass.
Stainless steel is not so good for higher freq, but you see from curve that can be used.

I bet you can make some good ones with aluminum flashing, like as used on roofing. Easy to make into cones. In some places copper is a common flashing material. Even better. A mesh material like aluminum window screen would work great. You can cut it in half with a ground plane and you have a discone. Antennas are a lot of fun. I read an article about someone who used a bridge across a river as an antenna and made some contacts. Hmmmm…, my deck has a metal framework, I think I will hook my antenna analyzer to it and see where it resonates.

Very cool Ikea hack and should be nice for Mode S reception too :sunglasses:

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What IKEA cones are you using?

http://www.ikea.com/hr/hr/catalog/products/30081467/
300.814.67
Regards
Djani

Thanks!

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Hey Guys,

My antennas are working good. I want to say thanks for the help. I was fun learning and making them.

For the next step, I’m not sure where to start, the app forums seem inactive now. I need an app that can be a frequency counter and waveform generator. Its for a Rife-type use.

A programmer I know said he thought it wouldn’t be too hard, still hasn’t worked on it much, but doens’t know much about radio programing, so the project has stalled.

He wanted to code it from scratch in the language Haskell, but I don’t think he knows how the code should be written to control the LimeSDR, how to create different waveforms, etc. Or what languages would be best to code in.

I only know html/css. I wish I knew how to do it myself, or could find help with this. I don’t have much money now.

Thanks guys/gals.