In QST Jan 2000 the ARRL published some specifications about receivers
including the Icom R75. Regarding the R75 it stated that the Noise Floor
(mds) is -130dBm under certain specific conditions. It also states that the
AM Sensitivity, 10dB (S + N)/N, under the same conditions is 1.7uV.

I am trying to equate the two specs into the same units. -130dBm is equal to
0.071uV; 1.7uV is equal to -102.5dBm. That is a difference of 27.5dB.

It is my understanding (and this is where the fault probably lies) that 10dB
above the noise floor should put the signal at -120dBm, which is 0.22uV not
1.7uV. They are putting the signal at -102.5dBm. Where is the extra 17.5dB
loss coming from? Doesn't 10dB (S + N)/N mean 10dB above the noise?

All input is greatly appreciated. Thank you.

Al KA5JGV