[time-nuts] Keysight N5511A - phase noise measurements down to theoretical-177 dBm/Hz

[ed breya]

That's quite an impressive system. I guess it's a few generations beyond 
my 11729C.

One way to get overall performance to the limits of room temperature kT 
noise level, is to lower the T where you work. I wouldn't be surprised 
if some parts are TE-cooled, easily affordable in a big budget system. 
My first thought was maybe a bunch of stuff in a cryogenic system, but 
it looks like most pieces are modules in a rack mainframe, and not in a 
special environment. But, within the modules, I could picture some 
degree (PTP) of TE-cooling being included, giving some margin on the 
capabilities.

Ed