[time-nuts] Re: Lowest noise (phase noise and ADEV) method to achieve 10 MHz signal from 5 MHz input

[Andy Talbot]

Your push-pull doubler is much nicer than my full-wave rectifier with
Schottky diodes
http://g4jnt.com/10MHzDist.pdf

Andy
www.g4jnt.com



On Mon, 29 Nov 2021 at 15:42, Wilko Bulte <wkb at xs4all.nl> wrote:

> For those interested, Dave PA5DOF and your's truly are working to get the
> doubler implemented that Luciano has on his website. The first PCB
> prototype is in and has been built and works OK. Some minor tweaks/fixes
> will be added to a V0.2 PCB. If there is interest I can share the Gerber
> files.
>
> The doubler is intended to be hooked up to an Efratom MRK-HLN 5MHz Rb. Our
> shack T&M equipment for the best part requires a 10MHz reference.
>
> Wilko
>
> > On 29 Nov 2021, at 10:35, timeok at timeok.it wrote:
> >
> > 
> >   you can use this:
> >
> >
> http://www.timeok.it/wp-content/uploads/2015/08/high-performance-frequency-doublerv1-31.pdf
> >
> >   Luciano P. S. Paramithiotti
> >   timeok at timeok.it
> >   www.timeok.it
> >
> >   Da "Matt Huszagh" huszaghmatt at gmail.com
> >   A time-nuts at lists.febo.com
> >   Cc
> >   Data Sun, 28 Nov 2021 19:29:58 -0800
> >   Oggetto [time-nuts] Lowest noise (phase noise and ADEV) method to
> achieve 10 MHz signal from 5 MHz input
> >   Hi,
> >
> >   I've got a 10 MHz distribution amplifier and am considering purchasing
> a
> >   5 MHz reference. Most (not all) of my equipment accepts a 5 MHz
> >   reference, but I'd like to be able to use the existing distribution
> >   amplifier I have if possible. Therefore, I'm considering ways I might
> >   generate a low-noise 10 MHz signal from the 5 MHz reference.
> >
> >   An obvious way is to use a doubler. However, as I understand it, even
> an
> >   ideal doubler will add 20log(2)=6 dB of phase noise to the 10 MHz
> >   signal. It seems like a possibly more expensive, but lower noise way
> >   would be to use a PLL with a divider that locks the divided 10 MHz
> >   signal to the 5 MHz input. If the time constant of the loop filter is
> >   set long enough, does this avoid the phase noise multiplication issue?
> >   From what I've gathered, this is a technique HP used in some of their
> >   gear. For example, the 8566 and 8340/1 lock a 100 MHz VCXO to an
> >   external reference with a PLL.
> >
> >   Any other thoughts on this?
> >   Matt
> >   _______________________________________________
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