New LimeSDR-USB not working properly

Hello, I’m new to LimeSDR. I just received a new LimeSDR-USB board and I’m a little confused.
I downloaded and installed the latest version of LimeSuite GUI for windows 10 and I tried understand if the board is ok. LimeSDR-USB is detected and the driver assigned correctly. The GUI sees the LimeSDR and connects to it.
I opened the FFT viewer set Nyquist frequ. to 7.5 MHz and pushed the star button. There is no spectrum appearing for several tenth of second and once the spectrum appears (when it appears) it no not updates at all…
I run the LimeQuickTest which tells me that everything is OK. Searching on the web i found out that the spectrum view should be responsive and with a good refresh rate.

Do I miss something.?
I used the board default settings (I just changed the LO frequency) which I was expecting to be able to generate a smooth spectrum. Isn’t it ?
Is there something wrong with the board ?

Thanks in advance, Joel

Hi! Have you tried the WCDMA test described here?

Yes, I tried both WCDMA and the " Receiving a signal " test.
both WCDMA and “Receiving a signal” are running for about 1.5s then they gets stuck till I press STOP and START again.

Same story on Linux (different PC)

I suppose both tests should produce a spectrum till I press STOP, isn’t it ?

Tagging @Zack.

some more details: I’m using the PC (Windows10) on which I did the LimeSDR tests for running our GNSS SDR which streams continuously up to 250 MBytes/s over the USB 3.0 connection. This points me into the direction of excluding any USB/Windows issues on the host side…

Device: LimeSDR-USB, media=USB 3.0, module=FX3, serial=0009081C05C32639, index=0, HW=4, GW=2.23 Serial Number: 0009081C05C32639

Hi @joebre,

Would suggest to do the following steps (assuming LimeSuiteGUI):

  1. Connect to the board;
  2. Push “Default” button;
  3. Go to CGEN tab and push “Tune” button. Perform the same for SXT and SXR tabs;
  4. Try FFTViewer now.

The “stream freezing” issue which has been solved by using an external power supply. Power trough USB seems to be the root cause of the observed instability.

Many thanks for the help… Joel

If using USB2, an external supply is usually needed. Please use 8VDC or less.
If using a USB3 hub, use a quality one, as the cheap ones will not provide enough power.
Most USB3 ports in computers “Should” supply enough power.


Hello… one question about the 8 VDC power supply …

Why 8V instead of the 12 VDC reported on the documentation (5…12 VDC if I remember well)? is there any reason for this (we planned to use LimeSDR with a 12 VDC power source)

I’m not sure, but I might’ve seen reports here on the forums about voltages higher than 8 damaging the board. I opted for an intermediate DC-DC converter in front of the external power input - just to be safe with the 13.8V car power grid.

Many have used inexpensive 12VDC wal warts that may have higher voltages. The “Power switch” IC is sensitive & has failed numerous times. Mine did. I then bridges 2 solder pads to use only USB power on both of my Limes. Using a good quality hub, I can run both at the same time. I have never had more than 750ma draw on the USB (Metered outboard).
This is why I state 8VDC.


Well I can tell you from my experience is that Lime SDR is total junk. Mine hasn’t worked properly from day 1 and the company (Crowd Supply) refuses to take it back or return e-mails or phone calls. I have reported Crowd Supply to the BBB and Crowd Supply refused to answer their e-mails/calls as well. Use it for a door stop because that’s about all it’s good for. Get yourself a Hack RF One, much better product.

@rjhidde I see from your other posts that you had issues using a particular piece of software. Have you tried others, such as SDRangel or SDR Console? If it passes LimeQuickTest OK it should be “working properly” and for general purpose receiver use, most people tend to use one of these two applications. Since we don’t develop these or SDR#, we cannot give any guarantees as to their operation however.

Additionally, SDR-Console has full TX support for the LimeSDR-USB, now. Works excellent !


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