"Joel Koltner" wrote in
:

....
Here's a question for you: What's the noise output power of your
run-of-the-mill RF signal generator (e.g., an HP 8594A/B/C)? I'm
thinking the noise output power is *well* in excess of kTB (where T is
the room temperature you're operating the generator in)?

Most SSGs will have a large attenuation at the output, and as the output
level is reduced (attenuation increased), the noise power density away from
the carrier approaches kT/Hz.

Owen