Thinking about it a bit more, if your spur appears 6 dB too *low*, that wouldn't be accounted for by the mixer-as-phase-detector correction factor. It's in the wrong direction. Failure to apply that correction would make your spur appear 6 dB too high.
Out of curiosity, does it matter which spectrum analyzer (3561A versus 3585A) you use to verify the spur amplitude? -- john, KE5FX > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Behalf Of John Miles > Sent: Thursday, January 17, 2008 10:54 AM > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] PM-to-AM noise conversion (was RE: New Question > onHP3048A Phase Noise Test Set) > > > > > I confirm the spur level on the spectrum analyzer. However the > > 3048A always > > says the spur is 6 dB lower than it actually is (6 dB > plus/minus 0.5 dB). > > > > Can anyone tell me why this is so. > > > > I wondered if it had something to do with phase noise and > amplitude noise > > not being the same thing. > > That sounds likely. It's interesting to think about where that 6-dB fudge > factor might be coming from... _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
