Demonstrating the Dynamic Range on the SDRplay RSP

The SDRplay radio spectrum processor (RSP) is a $150 USD software defined radio that can be considered as a next stage level up from the RTL-SDR dongle. We also consider it a competitor to the $199 USD Airspy SDR.

Over on YouTube the SDRplay designers have posted a video that demonstrates the dynamic range that is possible with their SDR. Dynamic range is a measure that defines the range between the strongest and weakest signal that can be received. So for example, if you have two signals near to each other on the frequency spectrum, dynamic range defines how much stronger can one signal be compared to the other before the weaker signal disappears into the noise.

In the experiment they use two frequency generators to generate a simulated wanted signal at 98.4 MHz and an unwanted blocking interferer at 98.7 MHz. They show that by reducing the IF bandwidth in their configuration screen and thus tightening the internal filters that the dynamic range can be increased to about 70 dB.

Previously Leif sm5bsz performed some similar tests, comparing many SDRs against one another, but did not utilize the programmable IF filters in the SDR Play RSP perhaps undervaluing the best possible dynamic range by about 5-10 dB.

SDRplay RSP FM Dynamic Range Demo

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Dynamic range isn’t necessarily the difference between the biggest and the smallest signal simultaneously. Making separate measurements would put the dynamic range at around >110dB, which would be a much more accurate and useful result. Good work with the video and keep up the testing!!!!


The video was made before even SM5BSZ lab testing. The new old thing?


Time travel ?

Published on 2 Nov 2014 – SDRplay RSP FM Dynamic Range Demo
Published on 11 Jan 2015 – SDR on 88-108 FM part1
Published on 20 Jan 2015 – SDR on 88-108 FM part2
Published on 14 Jun 2015 – SDR on 88-108 FM part3