Compare the NF of ATF33143feb with the NF of ATF33143
(Jan 30 2013)
Sorry, this screen dump is lost. The average S/N is -0.1730 for ATF33143feb while the ATF33143 shows S/N=-0.2442 with a known NF of 0.2525 dB. The correction for the S/N scale to show NF (with reversed sign) is to add -0.0083 dB.

From this comparison one would conclude that the NF of the ATF33143feb is 0.1813 dB.