"Jim Lux" wrote in message
...
For example, an Agilent N5181 looks like the noise floor is
around -160dBc/Hz well away from the carrier (e.g. 10MHz). That's probably
representative of the overall noise floor with the carrier at some level
like 0dBm. If we take that level, then it's 14 dB above kTB of -174 dBm/Hz

Thanks. Presumably then if you dial the carrier power down much below -14dBm
you're then going to have a -174dBm/Hz noise floor due to the output
attenuators as Owen mentioned...

---Joel