Lime seems incapable of detecting any changes radiation as the sun sets

Hey guys. My Lime seems to be pretty useless at the moment. I ran it outside yesterday over about 6 hours from 4-10 as the sun set. I was hoping to at least notice a change in intensity in any frequency band. I’m using a waveguide that’s tuned to 1.3 GHz, but I feel like there’s no real difference in results when I use that, the stock monopoles, or no antenna.

I used QSpectrumAnalyzer to do a large sweep over 1.2 GHz to 2 GHz just to try notice any changes, but I got nothing. Then I ran it again from inside and got the exact same plot. Here’s my plot, it hit an error after 4 hours and stopped, so I restarted it and patched it together in paint (not the most technical, I know).

Any reason why this might not be working? I’d love to have this sorted so I can start looking at some decent signals.

Okay, nevermind that comment about the antennas making a difference, here’s a little comparison between the stock monopole, the waveguide I’m using, and no antenna at all.

The question remains, why can I not detect the changes in radiation as the sun sets?

You are producing Ghostbusters II theme :smile:

You need good gain antenna and LNA in front of LimeSDR for that.
So add parabolic reflector of at last 3-4 m in front of that wave guide and LNA4ALL,
than please report here again…

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I ain’t afraid of no ghosts.

Alright, so the LNA of the Lime isn’t enough. Sure sure, thanks for the heads up. I probably should’ve gone for a cheaper SDR and an external LNA, but suppose I’ll keep that in mind next time.

While I have you, any idea what those signals at around 1.8-2 GHz would be? Maybe cell signals?

Yep, G4 cell networks…

Any tips on classifying cell signals? Like looking at their bandwidth or frequency? Any resources would be appreciated.

Start from Wiki than google on further…

Thanks man, appreciate it!

Also know what frequencies you are looking for.

For the Hydrogen line it will be centred on 1420MHz with some Doppler smearing to either side (Sol rotation combined with earth rotation+orbital shifts).

You probably want to filter ~100MHz on either side with either a bandpass filter or a set of low pass and high pass filters tuned for that window.
And the LNA, put it before the filters for best results.

Also, you can read this post from 9A4QV ->

and about H line band pass filter too ->