[time-nuts] E1938A PN measurments

[Bob Camp]

Hi

….. any bets on it being a triple oven? :)

Bob

On Sep 30, 2012, at 1:26 PM, Tom Knox <actast at hotmail.com> wrote:

> 
> Rick it is really fantastic to see Time Nuts occasionally discuse different aspects of products they actually designed. This form is really a treasure.
> In the future it would be interesting to here how you would approach the next quartz industry standard. The next generation Blue-Top or BVA.
> Thanks;
> Thomas Knox
> 
> 
> 
>> Date: Sun, 30 Sep 2012 10:03:03 -0700
>> From: richard at karlquist.com
>> To: time-nuts at febo.com
>> Subject: Re: [time-nuts] E1938A PN measurments
>> 
>> I recently modified an old 10811 to bring out the crystal
>> leads on miniature coax (instead of having them connect
>> to the oscillator circuit).  This allowed me to measure
>> the crystal's inherent flicker noise of frequency.
>> The measurements indicate that the 10811 phase noise out
>> to at least 100 Hz is entirely due to the crystal.
>> An interesting aspect of flicker noise of frequency
>> is that Allan deviation is independent of tau.  Thus,
>> just one number describes the crystal noise.
>> 
>> Rick
>> 
>> On 9/30/2012 4:44 AM, Bob Camp wrote:
>>> Hi
>>> 
>>> Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator.
>>> 
>>> Bob
>>> 
>>> On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist <richard at karlquist.com> wrote:
>>> 
>>>> The E1938A uses a crystal that is basically the same as
>>>> the 10811 crystal except that it is in a reduced height
>>>> package.  However the phase noise is not as good as a
>>>> 10811 due to broadband noise in the automatic frequency
>>>> control circuit.  By the time I discovered this, it
>>>> was too late to try to fix it.
>>>> 
>>>> Rick Karlquist N6RK
>>>> E1938A designer
>>>> 
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-nuts at febo.com
>>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>> and follow the instructions there.
>>> 
>>> 
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> 
>>> 
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
> 		 	   		  
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.