[time-nuts] Looking for Wavecrest Visi

[SAIDJACK at aol.com]

In a message dated 4/7/2007 00:00:25 Pacific Daylight Time,  
bg at lysator.liu.se writes:

On the  only "time-nut visit" I have done, the nut was VERY proud of his
Wavecrest!  You do not think the userbase is limited by pricelevel  and
availability?



Hi Bjoern,
 
there is one on Ebay today for $900 buy-it-now, with all accessories.  There 
is a bunch of others too, but too expensive in my opinion.
 
Sometimes they go for around $500 or even less on Ebay.
 
BTW: I don't believe in the tricks played by a lot of OCXO vendors to take  a 
(typically 100KHz BW limited) phase noise measurement and claim to be able to 
 calculate RMS jitter out of that for their crystals. Some vendors even have  
Excel spreadsheets on their website for this. Then they claim numbers such as 
 0.5ps RMS jitter etc.
 
Almost all crystal vendors use this method, but what about the  -10dBc/Hz 
spur at 115KHz that they don't even see on their phase noise plots??  How about 
the spur at -100Hz offset on the other sideband not visible in the  plot??
 
The Wavecrest unit has up to 2GHz bandwidth, and will see all spurs/noise  in 
that bandwidth and show a more 'true' RMS/Max jitter number/histogram.
 
AVXcorp and Kyocera are better equipped and use these DTS instruments to  
specify their oscillators in their datasheets.
 
Having an Ebay search saved, I see them more often on Ebay than HP's  5370's.
 
They are much more usefull with the Visi software running on a PC though,  
and I have been desparately trying to find a copy. I did buy my older (DOS)  
based Visi from Wavecrest, but have had no luck finding a version that runs on  
Win2K :(
 
bye,
Said



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