LimeSDR as Software Radio Spectrum Analsyer (GNU Radio)

Hi all,

I’m trying to build a software radio spectrum analyser with GNU Radio and LimeSDR. I’m following the tutorial on:
https://wiki.gnuradio.org/index.php/Guided_Tutorial_Hardware_Considerations

My flowgraph looks like this:

My settings for frequency is of the range:
100kHz to 3.8GHz

Gain: 0 to 70

Sample rate: 32M

However the output I’m getting is:

I’m expecting the frequency for local radio station to spike up, from what the gnuradio wiki is stating. I’ve tried sliding the gain and frequency bars around but no change is observed.

I’m thinking if there is anything wrong with the values I have inputted or am I using the wrong blocks?

I have connected LimeSDR antenna and HackRF antenna to RX1_H and RX1_L respectively

Any help is appreciated! Thanks

Wei