I agree with Al, these look like extremely good numbers.
I find measured sensitivity numbers a bit difficult to correlate on my own test bench, and there are a few sources of possible error. First, many FM generators (like my old Sound Technology 1000A) have a 50-ohm output, so you need to use a matching network for proper calibration of the output into either a 75-ohm or a 300-ohm antenna input, and add the attenuation of this network to the signal-level dial calibration. Second, I find that there are a handful of RF-noisy devices around my bench, and sometimes don't feel like turning them all off to get a super-precise measurement. And there's the matter of the disparity of your mono vs. stereo readings - if the composite or pilot modulation level on the signal generator is off a bit, then it will show up here.
But if your tuner is indeed acheiving the performance you describe . . . it's working just fine.
I find measured sensitivity numbers a bit difficult to correlate on my own test bench, and there are a few sources of possible error. First, many FM generators (like my old Sound Technology 1000A) have a 50-ohm output, so you need to use a matching network for proper calibration of the output into either a 75-ohm or a 300-ohm antenna input, and add the attenuation of this network to the signal-level dial calibration. Second, I find that there are a handful of RF-noisy devices around my bench, and sometimes don't feel like turning them all off to get a super-precise measurement. And there's the matter of the disparity of your mono vs. stereo readings - if the composite or pilot modulation level on the signal generator is off a bit, then it will show up here.
But if your tuner is indeed acheiving the performance you describe . . . it's working just fine.