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

**URL:** <https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926>\
**Category:** LimeSDR\
**Created:** [27 October 2017 07:42 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926 "2017-10-27T07:42:50Z")\
**Posts on this page:** 10\
**Page:** 1

<div class="post-metadata">

**Author:** ![Fshkie](https://avatars.discourse-cdn.com/v4/letter/f/919ad9/32.png) [@Fshkie](https://discourse.myriadrf.org/u/Fshkie)\
**Post date:** [27 October 2017 07:42 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926/1 "2017-10-27T07:42:50Z")

</div>

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).

 ![318 s](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/b/bed9d569df2efb29949163c339ed9f605d09a7ed.png)

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

---

<div class="post-metadata">

**Author:** ![Fshkie](https://avatars.discourse-cdn.com/v4/letter/f/919ad9/32.png) [@Fshkie](https://discourse.myriadrf.org/u/Fshkie)\
**Post date:** [27 October 2017 08:34 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926/2 "2017-10-27T08:34:12Z")

</div>

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.

 ![Comparison](https://yyz2.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/1/12682aed3ba17af8b3342801def41c75ad83f45c.png)

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

---

<div class="post-metadata">

**Author:** ![9a4db](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/9a4db/32/2675_2.png) [@9a4db](https://discourse.myriadrf.org/u/9a4db)\
**Post date:** [27 October 2017 08:36 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926/3 "2017-10-27T08:36:23Z")

</div>

You are producing Ghostbusters II theme 😄

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…

---

<div class="post-metadata">

**Author:** ![Fshkie](https://avatars.discourse-cdn.com/v4/letter/f/919ad9/32.png) [@Fshkie](https://discourse.myriadrf.org/u/Fshkie)\
**Post date:** [27 October 2017 08:45 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926/4 "2017-10-27T08:45:40Z")

</div>

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?

---

<div class="post-metadata">

**Author:** ![9a4db](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/9a4db/32/2675_2.png) [@9a4db](https://discourse.myriadrf.org/u/9a4db)\
**Post date:** [27 October 2017 08:47 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926/5 "2017-10-27T08:47:40Z")

</div>

Yep, G4 cell networks…

---

<div class="post-metadata">

**Author:** ![Fshkie](https://avatars.discourse-cdn.com/v4/letter/f/919ad9/32.png) [@Fshkie](https://discourse.myriadrf.org/u/Fshkie)\
**Post date:** [27 October 2017 08:53 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926/6 "2017-10-27T08:53:56Z")

</div>

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

---

<div class="post-metadata">

**Author:** ![9a4db](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/9a4db/32/2675_2.png) [@9a4db](https://discourse.myriadrf.org/u/9a4db)\
**Post date:** [27 October 2017 08:58 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926/7 "2017-10-27T08:58:53Z")

</div>

Start from Wiki than google on further…

> **[Comparison of mobile phone standards](https://en.wikipedia.org/wiki/Comparison_of_mobile_phone_standards)**
>
> This is a comparison of standards of mobile phones. A new generation of cellular standards has appeared approximately every tenth year since 1G systems were introduced in 1979 and the early to mid-1980s.
> Global System for Mobile Communications (GSM, around 80–85% market share) and IS-95 (around 10–15% market share) were the two most prevalent 2G mobile communication technologies in 2007. In 3G, the most prevalent technology was UMTS with CDMA-2000 in close contention.
> All radio access technolog...

---

<div class="post-metadata">

**Author:** ![Fshkie](https://avatars.discourse-cdn.com/v4/letter/f/919ad9/32.png) [@Fshkie](https://discourse.myriadrf.org/u/Fshkie)\
**Post date:** [27 October 2017 08:59 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926/8 "2017-10-27T08:59:46Z")

</div>

Thanks man, appreciate it!

---

<div class="post-metadata">

**Author:** ![M0GLO](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/m0glo/32/999_2.png) [@M0GLO](https://discourse.myriadrf.org/u/M0GLO)\
**Post date:** [28 October 2017 20:30 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926/9 "2017-10-28T20:30:01Z")

</div>

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.

---

<div class="post-metadata">

**Author:** ![9a4db](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/9a4db/32/2675_2.png) [@9a4db](https://discourse.myriadrf.org/u/9a4db)\
**Post date:** [2 November 2017 08:45 UTC](https://discourse.myriadrf.org/t/lime-seems-incapable-of-detecting-any-changes-radiation-as-the-sun-sets/1926/10 "2017-11-02T08:45:26Z")

</div>

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

> **[2x LNA4ALL for the Hydrogen line measurements](http://lna4all.blogspot.com/2008/09/2x-lna4all-for-hydrogen-line.html)**
>
> The LNA4ALL is a wide band LNA that cover also the Hydrogen line, 1420 MHz frequency. I receive a lot of e-mails from the guys asking for t...

  
and about H line band pass filter too -\>  

> **[Hydrogen line 1420 MHz filter](http://adsbfilter.blogspot.com/2015/06/hydrogen-line-1420-mhz-filter.html)**
>
> After announcing the ADS-B filter we receive some inputs asking for other type of the filters. One of them is filter commonly used by the ...