One of my 5370A's had a severely distorted sine out, which Bruce helped me trace to a bad solder joint on one of the cap that is part of the output filter. After reflowing the solder joint, it all came to life with a pretty good sinewave output.
Some of the caps on the amplifier board look different than most others. I suspect they were maybe higher grade, but the leads must have been a different alloy. Didier -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dr Bruce Griffiths Sent: Saturday, June 09, 2007 4:55 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] another Ebay mixup, 5370 [EMAIL PROTECTED] wrote: > Hi Tom, > > this was the recommended setup (by HP) for checking the internal > noise. Feed the 10MHz output back to the input using a short cable, > and set the unit for "COMMON" input, setting 50 Ohm impedance etc. > > In the meantime I did some more tests, and found the following: > > 1) The sine-wave output is crappy. The sine wave has some sort of > "Class-B" cross-over distortion, and it measures a whooping 200ps RMS > jitter on my Wavecrest jitter analyzer (>400ps pk-pk). Compare that > to 2.7ps RMS jitter I measure on our Fury 10MHz output. Definitely > the crystal got damaged, or something else. > > The unit has about 2x better jitter performance (around 50ps RMS) if I > feed a clean Fury 10MHz into it. I think the 10811 OCXO or the > internal driver circuit may have gotten damaged. > > > thanks, > bye, > Said > Said Can you send an image of the rear panel sinewave output waveform? Bruce _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.472 / Virus Database: 269.8.13/842 - Release Date: 6/9/2007 10:46 AM _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts