problem imagening the meaning of phase noise definition -70dbc/hz at 10Khz

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yefj

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Hello,From Wikipedia i have the following definition, but i cant imgine it.
Noise is not deterministic it has a variance and other properties of a random type.

dBc means ratio in amplitude between the carrier and some point
here we have some random thing so how ding /HZ helps us catch soe value from it?

Phase noise (ℒ(f)) is typically expressed in units of dBc/Hz, and it represents the noise power relative to the carrier contained in a 1 Hz bandwidth centered at a certain offsets from the carrier. For example, a certain signal may have a phase noise of −80 dBc/Hz at an offset of 10 kHz and −95 dBc/Hz at an offset of 100 kHz. Phase noise can be measured and expressed as single-sideband or double-sideband values, but as noted earlier, the IEEE has adopted the definition as one-half of the double-sideband PSD.
 

It's Average Noise Power measure in 1Hz Bandwidth.Random does not mean "non measurable".
Random Processes are characterized their "Average Values"
 

Its measure of PSD, think of regular WGN, its random in time but have PSD = const for all frequencies.
 

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