I don't know if this has been previously reported in this group, but
Adam Farson published his test results of the Airspy HF+ in April
http://www.ab4oj.com/sdr/airspy/airspy_hf_notes.pdf . In it he
concludes that the Airspy HF+'s Noise Power Ratio (NPR) measured
between 62 dB and 54 dB is "By comparison, the Perseus has 75 dB NPR
at higher noise loading levels, i.e. higher signal strength per
Are these test results also appropriate for the Airspy HF+ Discovery?