A few days ago we posted about Hayati and others' work in creating a new release of the librtlsdr drivers which implemented some new interesting features. However, at the time of the post there was no GUI for actually making use of the features easily. Now Hayati has released a new rtl_tcp ExtIO interface.
The interface exposes the ability to manually adjust the filtering within the R820T tuner. This is quite useful for managing out of band interference and raising overall dynamic range especially when trying to listen to a narrowband signal. It also exposes decimation controls, tcp connection features like auto reconnect and persistent connection, manual IF gain control, the ability to choose USB vs LSB tuning, and the ability to choose the highest stable sample rate of 2.56 MSPS.
The ExtIO interface is only available for SDR programs that support ExtIO, such as HDSDR. To test the ExtIO, first download and extract the latest librtlsdr release then run rtl_tcp from the command line. Extract and run the new ExtIO dll into the HDSDR folder, then run HDSDR, making sure to select the new dll when it asks on startup. You can then set the desired bandwidth and the matching decimation settings for that bandwidth.