Empathy List Archives

JR

James Robbins

Sat, Jul 9, 2016 7:48 PM

Would doubling the frequency of a 5 MHz oscillator to 10 MHz affect (or degrade) the natural ADEV of the 5 MHz oscillator? If so, how does it affect the original ADEV? Is there a preferred frequency doubler circuit which would do the least harm to the ADEV of the oscillator? The signal can be a square wave and does not need to be a sine wave. Thanks. Jim Robbins

CS

Charles Steinmetz

Sat, Jul 9, 2016 9:57 PM

James wrote:

Is there a preferred frequency doubler circuit which would do the least harm to the ADEV of the oscillator? The signal can be a square wave and does not need to be a sine wave. Thanks. Jim Robbins

A quadrature-fed DBM produces the lowest jitter and noise. My
implementation can be found at:

http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/4_App_Notes_and_Articles/Frequency_doubler_quadrature_DBM.pdf

A well-designed push-push frequency doubler is probably second (but note
that many push-push designs you find on the web have various common
design flaws). My implementation can be found at:

http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/Frequency_doubler_push_push_JFET_schematic_description_discussion.pdf

Best regards,

Charles

James wrote: > Is there a preferred frequency doubler circuit which would do the least harm to the ADEV of the oscillator? The signal can be a square wave and does not need to be a sine wave. Thanks. Jim Robbins A quadrature-fed DBM produces the lowest jitter and noise. My implementation can be found at: <http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/4_App_Notes_and_Articles/Frequency_doubler_quadrature_DBM.pdf> A well-designed push-push frequency doubler is probably second (but note that many push-push designs you find on the web have various common design flaws). My implementation can be found at: <http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/Frequency_doubler_push_push_JFET_schematic_description_discussion.pdf> Best regards, Charles

BC

Bob Camp

Sat, Jul 9, 2016 11:54 PM

Hi

The simple answer is that most doublers that are ok for phase noise will not degrade ADEV.
The issues with ADEV come when your doubler is out in a changing environment and your
oscillator is not ( = it’s an OCXO). The answer to that problem is pretty simple if you have an issue …
ovenize the doubler.

Bob

On Jul 9, 2016, at 3:48 PM, James Robbins jsrobbins@earthlink.net wrote:

Would doubling the frequency of a 5 MHz oscillator to 10 MHz affect (or degrade) the natural ADEV of the 5 MHz oscillator? If so, how does it affect the original ADEV? Is there a preferred frequency doubler circuit which would do the least harm to the ADEV of the oscillator? The signal can be a square wave and does not need to be a sine wave. Thanks. Jim Robbins

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Hi The simple answer is that most doublers that are ok for phase noise will not degrade ADEV. The issues with ADEV come when your doubler is out in a changing environment and your oscillator is not ( = it’s an OCXO). The answer to that problem is pretty simple if you have an issue … ovenize the doubler. Bob > On Jul 9, 2016, at 3:48 PM, James Robbins <jsrobbins@earthlink.net> wrote: > > Would doubling the frequency of a 5 MHz oscillator to 10 MHz affect (or degrade) the natural ADEV of the 5 MHz oscillator? If so, how does it affect the original ADEV? Is there a preferred frequency doubler circuit which would do the least harm to the ADEV of the oscillator? The signal can be a square wave and does not need to be a sine wave. Thanks. Jim Robbins > _______________________________________________ > 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.

D

davidh

Sun, Jul 10, 2016 12:44 AM

Charles,

Thanks for the reminder about this... it will neatly solve a problem I
have at hand. Can you advise which core you used for the transformer?

Thanks,

david

On 10/07/2016 07:57, Charles Steinmetz wrote:

James wrote:

Is there a preferred frequency doubler circuit which would do the
least harm to the ADEV of the oscillator? The signal can be a square
wave and does not need to be a sine wave. Thanks. Jim Robbins

A quadrature-fed DBM produces the lowest jitter and noise. My
implementation can be found at:

http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/4_App_Notes_and_Articles/Frequency_doubler_quadrature_DBM.pdf

A well-designed push-push frequency doubler is probably second (but note
that many push-push designs you find on the web have various common
design flaws). My implementation can be found at:

http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/Frequency_doubler_push_push_JFET_schematic_description_discussion.pdf

Best regards,

Charles

Charles, Thanks for the reminder about this... it will neatly solve a problem I have at hand. Can you advise which core you used for the transformer? Thanks, david On 10/07/2016 07:57, Charles Steinmetz wrote: > James wrote: > >> Is there a preferred frequency doubler circuit which would do the >> least harm to the ADEV of the oscillator? The signal can be a square >> wave and does not need to be a sine wave. Thanks. Jim Robbins > > A quadrature-fed DBM produces the lowest jitter and noise. My > implementation can be found at: > > <http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/4_App_Notes_and_Articles/Frequency_doubler_quadrature_DBM.pdf> > > > A well-designed push-push frequency doubler is probably second (but note > that many push-push designs you find on the web have various common > design flaws). My implementation can be found at: > > <http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/Frequency_doubler_push_push_JFET_schematic_description_discussion.pdf> > > > Best regards, > > Charles > >

CS

Charles Steinmetz

Sun, Jul 10, 2016 2:51 AM

David wrote:

Thanks for the reminder about this... it will neatly solve a problem I
have at hand. Can you advise which core you used for the transformer?

If you mean the quadrature hybrid, I use an FT37-61 toroid core. One of
the smaller Mix 61 balun cores should also work, but with the toroid you
can trim the inductance by spreading or compacting the windings on the
core.

If you mean the transformers for the push-push FET doubler, I usually
use commercial parts (MCL or Coilcraft).

Best regards,

Charles

David wrote: > Thanks for the reminder about this... it will neatly solve a problem I > have at hand. Can you advise which core you used for the transformer? If you mean the quadrature hybrid, I use an FT37-61 toroid core. One of the smaller Mix 61 balun cores should also work, but with the toroid you can trim the inductance by spreading or compacting the windings on the core. If you mean the transformers for the push-push FET doubler, I usually use commercial parts (MCL or Coilcraft). Best regards, Charles

T

timeok@timeok.it

Sun, Jul 10, 2016 6:15 AM

Luciano
www.timeok.it

From: "time-nuts" time-nuts-bounces@febo.com
To: time-nuts@febo.com
Cc:
Date: Sat, 9 Jul 2016 17:57:57 -0400
Subject: Re: [time-nuts] Does doubling a frequency alter the original ADEV of the frequency?

James wrote:

Is there a preferred frequency doubler circuit which would do the least harm to the ADEV of the oscillator? The signal can be a square wave and does not need to be a sine wave. Thanks. Jim Robbins

A quadrature-fed DBM produces the lowest jitter and noise. My
implementation can be found at:

http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/4_App_Notes_and_Articles/Frequency_doubler_quadrature_DBM.pdf

A well-designed push-push frequency doubler is probably second (but note
that many push-push designs you find on the web have various common
design flaws). My implementation can be found at:

http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/Frequency_doubler_push_push_JFET_schematic_description_discussion.pdf

Best regards,

Charles

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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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See also: http://www.timeok.it/wp-content/uploads/2015/08/high-performance-frequency-doublerv1-31.pdf Luciano www.timeok.it From: "time-nuts" time-nuts-bounces@febo.com To: time-nuts@febo.com Cc: Date: Sat, 9 Jul 2016 17:57:57 -0400 Subject: Re: [time-nuts] Does doubling a frequency alter the original ADEV of the frequency? James wrote: > Is there a preferred frequency doubler circuit which would do the least harm to the ADEV of the oscillator? The signal can be a square wave and does not need to be a sine wave. Thanks. Jim Robbins A quadrature-fed DBM produces the lowest jitter and noise. My implementation can be found at: <http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/4_App_Notes_and_Articles/Frequency_doubler_quadrature_DBM.pdf> A well-designed push-push frequency doubler is probably second (but note that many push-push designs you find on the web have various common design flaws). My implementation can be found at: <http://www.ko4bb.com/getsimple/index.php?id=download&file=02_GPS_Timing/Frequency_doubler_push_push_JFET_schematic_description_discussion.pdf> Best regards, Charles _______________________________________________ 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.

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Does doubling a frequency alter the original ADEV of the frequency?