[time-nuts] another Ebay mixup, 5370
Dr Bruce Griffiths
bruce.griffiths at xtra.co.nz
Sat Jun 9 20:53:16 EDT 2007
John Miles wrote:
> Pretty similar results here, taken from the 5370B's rear-panel output while
> running on the internal 10811B (attached). Indicated jitter with this setup
> is about the same as it was on the ext ref via the 5087A (10-12 ps).
> I've seen this counter return self-test jitter results in the 15-25 ps range
> before. Not sure why it's in such a good mood today.
> At any rate, it doesn't appear that the wave shape is a problem... but of
> course, you will usually get better jitter readings with a fast edge than
> with a sine wave.
> -- john, KE5FX
Internal crosstalk can cause the 5370 to appear to be much better than
The jitter will vary as you vary the length of the cable connecting the
external 10MHz output to the input.
If the input is attenuated (inadvertently by internal fault or
otherwise) the jitter will increase considerably with a sine wave input.
It would be nice to have a look at the jitter spectrum (of Said's 5370
), to see if there are any line frequency related components.
After 20 years or less some of the power supply electros may be suspect.
More information about the time-nuts