[time-nuts] Method for comparing oscillators

[Bruce Griffiths]

Joseph M Gwinn wrote:
> Rex,
>
>
> time-nuts-bounces at febo.com wrote on 08/04/2009 07:35:51 PM:
>
>   
>> From:
>>
>> Rex <rexa at sonic.net>
>>
>> To:
>>
>> Discussion of precise time and frequency measurement 
>>     
> <time-nuts at febo.com>
>   
>> Date:
>>
>> 08/04/2009 07:43 PM
>>
>> Subject:
>>
>> Re: [time-nuts] Method for comparing oscillators
>>
>> Sent by:
>>
>> time-nuts-bounces at febo.com
>>
>> Bruce Griffiths wrote:
>>
>>     
>>> Rex wrote:
>>>
>>>
>>>       
>>>> Poul-Henning Kamp wrote:
>>>>
>>>>
>>>>
>>>>         
>>>>> In message
>>>>> <abec162c0908030758y62c9dffdq65f8341cd2bb84d1 at mail.gmail.com>, John
>>>>> Green writes:
>>>>>           
>>>>>> I have studied the dual mixer approach and the consensus is that it
>>>>>> is the
>>>>>> most accurate method. However, it seems pretty difficult to
>>>>>>             
>> obtain that
>>     
>>>>>> accuracy.
>>>>>>             
>>>>> Check the description and papers about Timing.com's way of doing it,
>>>>> they
>>>>> are quite clever.
>>>>>
>>>>>
>>>>>           
>>>> Poul-Henning,
>>>>
>>>> Can you give a more specific reference to the documentation? I took a
>>>> look around www.symmetricom.com/resources/ (where timing.com
>>>> redirects) but it is not clear to me that anything I found describes
>>>> their way of doing it.
>>>>
>>>>
>>>>         
>>> Rex
>>>
>>> Look at the TSC5115A and the TSC5120A (download and read the manuals)
>>> plus the associated patents.
>>>
>>> Bruce
>>>
>>>       
>> Bruce,
>>
>> Thanks, that looks interesting. I found the manual here...
>> http://www.symmetricom.com/media/files/support/ttm/product-
>> manual/5120A-MAN.pdf
>>
>> But I haven't figured out where to get a list of related patents. Can 
>> anyone provide key number(s) or point me to a list?
>>     
>
> I dug this up a year or two ago.  It was not easy to find, but the main 
> patent is US Patent 7,227,346 to Solbrig.  The patent text may be obtained 
> from www.pat2pdf.org or Google Patents.
>
> There may be another patent, but I don't know its number.
>
> The main article was "Direct-Digital Phase-Noise Measurement", J. Grove, 
> J. Hein, J. Retta, P. Schweiger, W. Solbrig, and S.R. Stein, 2004 IEEE 
> International Ultrasonics, Ferroelectrics, and Frequency Control Joint 
> 50th Anniversary Conference, pages 287-291, 
> 0-7803-8414-8/04/$20.00 (c)2004 IEEE.  Much of the text of this article 
> also appears in an appendix to the 5120 manual.
>
> Joe Gwinn
>
>   
Joe

7436166 is the other relevant patent.

Bruce