LimeSDR high sample rate time series dropout

Projects LimeSDR
1

Hello all,
I’m using a LimeSDR usb as a RF reciever with GNU radio and have noticed that at high sample rates (40 MHz) that there is a drop out in the IQ series. It seems constistantly spaced at ~12 us and occurs in both reciver channels at the same time so I was thinking it was some sort of buffer issue? Has anyone come across this before and would anyone be able to help? Any advice is welcome, pictures included below:
This is my gnu flowgraph for reference, I have a little transmitter nearby at that frequency.

gnuflowgraph
gnuflowgraph701×322 40.4 KB

This is the timeseries. Channels are at different levels because of an antenna length missmatch but notice the vertical lines in the plot.

timeseries
timeseries1880×973 316 KB

This is zooming in on one of those lines, where the data is dropping. You can see both channels drop synchronously.

timeserieszoomed
timeserieszoomed1881×967 111 KB

Thanks,
Pallin

2

Are you sure you’re not hitting any CPU limitations? Probably you should also use a throttle block.

3

Thanks for your reply but I found my problem in that I had used the wrong usb cable (2 not 3)! Still getting some data drops but I can live with it for now.

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