Over on the SDRplay forum, Mike Rooke has been checking out how coherent the two tuners of the RSPduo are. Using the sample v3 api code for windows he added code to dump both tuner IQ streams to stdout. An earlier version of the play_sdr command line app that he’d hacked together for his RSP2s under Linux already gave him antenna switching, tuning and frequency hopping. Taking the tuning bits of that code and porting it to windows enabled Mike to do basic testing of the RSPduo, to check how coherent both tuners are. – Mike summarises this as “in a  word, excellent”.

Here’s his video showing the duo tuning via a windows laptop streaming IQ samples (via netcat) to a Linux server running baudline.
https://urlme.net/dl/sdrduo-dualtuningtest.mp4

And a still capture
Image

Mike writes “The main learning with the API, was the getting the correct initialisation sequence to use for the dual tuner use, and updating the example code to actually output samples. You can see Mike’s forum post which includes the relevant example code expansion. It’s not a complete example, and needs incorporating/rewriting for the final requirements of your  particular application.  Go to:  https://www.sdrplay.com/community/viewtopic.php?f=7&t=3508