[time-nuts] State of the art of crystal oscillator measurements

John Miles john at miles.io
Thu Aug 11 19:57:22 EDT 2016

-177 = the -174 dBm/Hz SSB thermal noise floor at 25C, less 3 dB to account for the usual assumption that half of it is AM, half PM.   

dBm/Hz is obviously equivalent to dBc/Hz for a 0 dBm carrier.  

Anyone who claims to measure noise in a 1 Hz bandwidth below -177 dBm/Hz at room temperature is either doing something wrong somewhere, or doing something amazing somewhere.

-- john, KE5FX
Miles Design LLC

> -----Original Message-----
> From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Mike
> Feher
> Sent: Thursday, August 11, 2016 4:15 PM
> To: 'Discussion of precise time and frequency measurement'
> Subject: Re: [time-nuts] State of the art of crystal oscillator measurements
> That is why I asked what the Po was. Where did the 177 come from? L(f) is
> single sided. This is not my first "rodeo" in these matters. 73 - Mike
> Mike B. Feher, EOZ Inc.
> 89 Arnold Blvd.
> Howell, NJ, 07731
> 732-886-5960 office
> 908-902-3831 cell

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