[time-nuts] Phase noise measurement (was - no subject)

[Bob Camp]

Hi

If the sidebands are un-correlated noise then they add as power (3db). If they are correlated they add as voltage (6db). Noisy modulation processes produce correlated sidebands.

Close in noise likely comes from a modulation process. Far removed noise is unlikely to be a result of modulation.

Bob



On Aug 24, 2010, at 4:24 PM, dk4xp at arcor.de wrote:

> 
> 
> 
> Von:     Bob Camp <lists at rtty.us>
> 
>> If you start with a mixer that runs 500 mV / radian (an RPD-1 at the typical
>> 8 mV / degree + 10%) then -180 below that would be 0.5 nV. Since noise it
>> coherent close in, the DSB  to SSB process nets you 1 nV out when you have
>> -180 dbc noise. 
> 
> Adding the two sidebands may double the power, but not the voltage?
> 
> 
> 73, Gerhard
> 
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