Hi
> On May 31, 2016, at 6:30 AM, Dr. David Kirkby (Kirkby Microwave Ltd) > <drkir...@kirkbymicrowave.co.uk> wrote: > > On 30 May 2016 17:01, "Richard (Rick) Karlquist" <rich...@karlquist.com> > wrote: >> >> On 5/30/2016 4:06 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > >>> I'm wondering what's the best way to generate 116 MHz with very low phase >>> noise. Phase noise at < 20 kHz offset is particularly important, but 200 >> >> The "best" way is clearly to use a 116 MHz 5th overtone crystal >> oscillator, which can be locked to 10 MHz with no difficulty. >> I designed hundreds of these sorts of things 40 years ago when >> I worked for Zeta Labs. > > Please excuse my ignorance, but how would one lock a 116 MHz 5th overtone > crystal oscillator to 10 MHz with no difficulty? Do you have a circuit you > share that would give low phase noise, and if so how low? There are an enormous number of PLL chips that will do the trick for < $2 a pop. About the only external components are a couple of caps and resistors. > > From what I have read here before, amplifiers degrade the phase noise if > driven to near the 1 dB compression point. So would the final amplifier > need to have a 1dB compression point of 33, 36, 40 dBm? Indeed, no matter how you do it and no matter what your signal source, your amp will be an issue. A +40 dbm amp is a good starting point. You may get away with something a bit less. > > My next problem would be measuring the phase noise, but that's a different > topic for another day. Checking the phase noise will be part of the design no matter how you do it. Bob > > Dave. > _______________________________________________ > 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. _______________________________________________ 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.