[time-nuts] Re: Best frequency to start for GHz synth ?

[Bruce Griffiths]

The oscillator circuit consists of an SSM2210 supermatch npn pair configured as a long-tailed differential pair with a 12mA tail current and 51 ohm collector loads. One output feeds the output buffer whilst the other provides feedback to the crystal via an LC network that is series resonant at 10MHz and parallel resonant at 10.9MHz followed by a varactor tuned phase shift network connected to one end of the SC cut crystal.
The other end of the crystal drives the input of the diffamp via an RF step up transformer (ADT16-6T) with a grounded secondary centre tap.

Bruce  
> On 03 April 2021 at 01:36 Bob kb8tq <kb8tq at n1k.org> wrote:
> 
> 
> Hi
> 
> Unfortunately, even the numbers he quotes are going to be less than 
> ideal if multiplied directly to 10 GHz. Will they be “good enough” for 
> this or that? As always … that depends. It is rare to find any piece 
> of commercial gear that does it that way.
> 
> Bob
> 
> > On Apr 2, 2021, at 4:38 AM, John Moran, Scawby Design <john at scawbydesign.co.uk> wrote:
> > 
> > Since low phase noise seems to be a main requirement here, this paper by Jeremy Everard from York University may be of interest -
> > 
> > 'Ultralow Phase Noise 10-MHz Crystal Oscillators'
> > 
> > Available here -
> > 
> > https://ieeexplore.ieee.org/document/8540461
> > 
> > It also shows construction of a double oven system for it.
> > 
> > I believe Jeremy was working on sapphire oscillators 20 years ago when I worked at York for a while.
> > 
> > John 
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at lists.febo.com -- To unsubscribe send an email to time-nuts-leave at lists.febo.com
> > To unsubscribe, go to and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com -- To unsubscribe send an email to time-nuts-leave at lists.febo.com
> To unsubscribe, go to and follow the instructions there.