[email protected] wrote: > Hi Rick, > > In my experience the 53132 is not good for ADEV measurements below 100s. > It > is just way too noisy.
Now I vaguely remember: the buffer circuit for the external reference is a poor design, because the designers didn't know any better and didn't ask for help. (I knew the designers). So even though I am using the 10811 inside of an 8662A as an external reference, the 53132 won't get the full performance of it. I hope the 53230 is better. The counters are designed and made in Asia now, so I can't exercise the proverbial HP "next bench" paradigm very well when the bench is on another continent. > > You can try longer measurement gate and averaging times, but theoretically > the SD value should be similar for 100s or 1000s SD measurements if what > you are measuring is actually the internal noise of the counter (this is > what > I suspect). > I think you're right. I'm measuring a 10811 on the bench vs the 10811 in 8662. Interestingly, if I feed the 8662's 10 MHz output to both the external reference and the front panel at the same time, the display reads exactly 10 MHz most of the time, or occasionally drops by 1 count (1 part in 12). This would make it seem like the buffer inside is OK. Rick _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
