Bill,
I have a piece of the answer. I am using the BasicRX transformer
coupled receiver boards. With the programmable gain amplifier ahead of
the ADC set to a gain of 20 dB, I am measuring approximately -100 dBm
sensitivity for a 10 dB S+N/N in a 100-Hz bandwidth. These numbers all
need to be refined, but they should at least be in the ball park for the
USRP by itself.
Dick…