Thanks all for the suggestions. I am typically measuring 5 or 10 Mhz sine waves with levels between 1 and 4 volts peak to peak into a 50 ohm load.
To expand on my first email with suitable input signals I can see the 20 ps resolution of the HP5370B on a "strip chart" from time lab without any further effort. So far other than re seating the cards (which cured some lock up issues on a few of them) I haven't really done any maintenance to my HP5370's. I'm also using a 5 Mhz BVA as the reference oscillator for the HP5370B's in question which seems to improve things vis a vis the internal 10811's. At some point when I have some more time I'll delve into the reference oscillator matter in more detail as I'm a bit surprised at this. Magnus your suggestion to try attenuating the input signals makes a lot sense and I will try this as different signal levels do seem to make a difference. Re the other recent post re cable issues I've also encountered similar issues in the past and typically use RG400 double shielded cables. Regards Mark S Sent from my iPad _______________________________________________ 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.
