[time-nuts] 10MHz Rubidium reference source for frequency counter

Karen Tadevosyan ra3apw at mail.ru
Fri Oct 31 16:57:05 EDT 2014

Thank you, Charles. 

All OCXOs have been tested in free-running mode after 40-50 min of

All OCXOs have been installed in isolated close box to exclude external

Cases of all OCXOs had not any contact with external metallic parts of the



>Karen wrote:


>>The next OCXOs have been tested today:


>Did you test the oscillators free-running (NOT in your GPSDO)?  If 

>so, those plots look much too high (by at least an order of 

>magnitude, maybe even 2 or more OOM for some of the oscillators).


>Of course, oscillators take time to settle to their best stability -- 

>as much as several weeks or even several months for some -- so if you 

>just turned them on and measured them a few hours later you can 

>expect higher than normal ADEV results.  Even so, these results seem high.


>But if you measured them in your GPSDO circuit, you have not 

>separated the potential measurement problems from potential GPSDO problems.


>If you suspect the time base in the Pendulum, you can use one of the 

>OCXOs to feed its external reference input.


>Best regards,




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