Well, in my opinion, it was no more complex than what you had to offer, and there was never a mention of an FFT analyzer. FFT or not, it still has to see a detector first prior to an A/D. As I said, modern analyzers read No out directly in dBm/Hz, so, no correction is needed. The problem is more complex than you state as the -100 Hz does fold back and depending on the phase relationship with the + 100 Hz could cause discrepancies in readings of actual values. A typical spectrum analyzer usually allows you to go below DC, therefore the -100 Hz would probably be visible. The fact is, it does exist. A simple energy detector would measure the vector sum of the two. Pretty basic to me after doing it for close to 30 years. However, I am always open to new ideas and am happy to learn from any experience you may have to share. I just do not appreciate answers that do not contribute anything of additional value. Unfortunately, I did not see anything in your post that provided that additional value. Regards - Mike
Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bruce Griffiths Sent: Thursday, January 17, 2008 3:50 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] PM-to-AM noise conversion (was RE: New Question onHP3048A Phase Noise Test Set) Mike Feher wrote: > So - Bruce - what did you say that I did not? - > > > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 > > Mike You didnt clearly indicate why the 3048 reports the spur amplitude as 6dB lower than the spectrum analyser does. Your explanation is overly complex and confusing. You also mention several factors that are irrelevant when using an FFT spectrum analyser. Bruce _______________________________________________ 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. _______________________________________________ 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.
