[time-nuts] Notes on the Driscoll VHF Overtone Crystal Oscillator

Bruce Griffiths bruce.griffiths at xtra.co.nz
Mon Dec 28 05:52:12 UTC 2009


An inductor in series with the 220 ohm emitter resistor will improve the 
phase noise floor.
The MMIC output amplifier has a wider bandwidth than necessary and 
doesn't have a particularly high reverse isolation.
One could improve this by substituting a CB cascade or other discrete 
amplifier cascade.
Alternative methods of extracting the signal from the collector of the 
second transistor may be more effective in maintaining a low phase nose 
floor.

Bruce

Bob Camp wrote:
> Hi
>
> The feedback network in the Fig 7 schematic makes a lot more sense than the network in the first Fig 7 ....
>
> Bob
>
> On Dec 27, 2009, at 7:19 PM, Tom Clifton wrote:
>
>    
>> Interesting read on a low phase noise oscillator by Chris Bartram GW4DGU
>>
>>
>> http://www.christopherbartramrfdesign.com/blaenffos/oscillator/VLNO.pdf
>>
>>
>>
>>
>>      






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