> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Magnus Danielson > Sent: Sunday, April 06, 2008 6:18 AM > To: time-nuts@febo.com; [EMAIL PROTECTED] > Subject: Re: [time-nuts] GPS noise reduction > > Actually, in this application will a bit of interlocking not > hurt, as the two oscillators should longterm have the same > frequency and interlocking will pull them together to their > average frequency. If you further aid this interlocking by > externally couple them together for higher frequencies (up to > say 10-100 Hz) then you can sum their outputs and get a > reduced noise response, a 3 dB improvement. The noise > processes internal to the oscillators will be uncorrelated > where as the locking causes the signals to be in phase. > ... > > Cheers, > Magnus >
That's an interesting concept. One could couple a number of oscillators that way (provided it is practically feasible) and improve phase noise, like you can make a better LNA by paralleling several amplifiers. For that to actually be beneficial however, the locking effect should be mutual, i.e. each oscillator has the same effect on the other so that "averaging" (probably not the right term, but you get the idea) takes place. If coupling is assymetrical, then the dominant oscillator (the one that is less affected by the others but affects the others) will drive the result and you won't have any improvement over that oscillator alone. Since it is very hard in practice to control coupling between two devices unless you do it intentionaly (that means the devices are designed to be coupled in a controlled fashion), it may be best (easier in practice) to do everything you can to reduce coupling. Didier No virus found in this outgoing message. Checked by AVG. Version: 7.5.519 / Virus Database: 269.22.5/1358 - Release Date: 4/3/2008 6:36 PM _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.