LimeSDR Mini vs USB - Signal Saturation

Projects LimeSDR
1

Hi, I’m checking here the LimeSDR Support for OpenSatelliteProject and I noticed something weird. When running on LimeSDR USB everything goes fine, but on Mini the signal looks overly saturated. Even putting a hardware bandpass filter before the LimeSDR doesnt help much.

LimeSDR USB:

Captura%20de%20tela%20de%202019-02-23%2013-21-37
Captura de tela de 2019-02-23 13-21-37.png1853×1053 88.6 KB

LimeSDR Mini:

Captura%20de%20tela%20de%202019-02-23%2013-23-10
Captura de tela de 2019-02-23 13-23-10.png1853×1053 94.9 KB

I tried playing with the gains, putting a hardware attenuator, several bandpass filters, but none seens to help.

Any ideas what I can do?

2

Ok so I did few more tests here, and looks like the Mini SMA Connector are not good as LimeUSB ones, if I force the cable in, the NF reduces for some reason. Also adding another LNA Stage also helps a bit. I could get the same signal levels as the LimeUSB by holding the cable pressed against the lime mini, for the LimeUSB I dont need to do that.

3

Hello @racerxdl,

Could you post a picture of your board with cables connected, please.

4

Sure:

image
image.jpg694×926 128 KB

Its working now, I Just had to tight a bit more than I’m used to.

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