I have been experimenting with an MSi.SDR RSP1 clone from China for a short while and must admit I have only used it for relatively narrow span measurements. IMHO the RSP SA software has many nice features and is slick to use.
Attached is what the baseline looks like with a 1GHz span with no signal and terminated input and RBW of 500Hz. I have not done any calibration to match the software to this particular receiver. However this should illustrate the internal spurs without any signal input for this particular RSP1 clone.
It appears some switching takes place around 60 MHz and possibly a pre-amplifier is inserted at 420 MHz. I had the clock spur removal feature turned on which removed many spurs. There are significant spurs around 196 MHz and 401 MHz plus a few other low level spurs.
I suspect this software would work better with a genuine RSP1A that has more filtering. Unfortunately I don't have an RSP1A to make a comparison.?
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