[time-nuts] Looking for Wavecrest Visi

[SAIDJACK at aol.com]

In a message dated 4/8/2007 14:21:05 Pacific Daylight Time,  
tvb at LeapSecond.com writes:
 
>Said,

>One way to settle this is for you to collect a data  set
>of back-to-back single-shot time interval samples over
>GPIB  and have a look at the data. Even a hundred
>samples is enough; it will  take a fraction of a second;
>probably limited by GPIB  speed.


Hi Tom,
 
well - that's my main reason I did the post - I wish I had Visi for  
Windows2K so I could do exactly that!
 
I am trying to set up a Win98 machine with GPIB since I bought a quite  old 
version of Visi from Wavecrest that runs only on Win98.

>Doing this with a 5328, 5334, 5370, 5371, 53132, or
> 620,  etc. clearly shows what the native resolution of
> these machines  is.


See Magnus' email, down to 200 femtoseconds on the newer units.

>Do not use an averaging mode. All of the above TIC
>allow  averaging, and yes, with averaging you get a
>significant gain in apparent  resolution. But we're talking
>here about the single-shot resolution of  the hardware.


Will let you know once I get GPIB up and running.

>Related to that, about how many single-shot samples
>per  second can you get out of a Wavecrest?


According to their user manuals, 15,000 per second on a 2070 via GPIB, and  
up to 40,000 per second with the HiPer option (I don't know what that means) on 
 a DTS2075.
 
The SIA3000 and later models can probably do more, but I don't think they  
have two input A to B time interval measurements (I may stand corrected).
 
Bye,
Said





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