On 5/31/2016 3:30 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:
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?
If you extract the signal from the oscillator through the crystal (as done in the 10811), the oscillator will be inherently low phase noise, plenty good enough for your ham radio application. Hard to screw it up. If you phase lock the oscillator to 10 MHz using a very narrow bandwidth phase locked loop, say 10 Hz, you will not contaminate the crystal oscillator with reference noise. The purpose of the PLL here is not to "clean up" the XO, but to merely remove drift. Again, hard to screw it up. I can't quote exact phase noise numbers from 40 years ago, but the Zeta Labs sources were sold to very demanding aerospace customers, all big names you would have heard of. Rick N6RK _______________________________________________ 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.
