OK that gives me some hope that I can make this thing work. I have started the calibration process and got to the second step that requires a short duration pulse. I don't know how I will do that yet. Maybe I will skip that item and go to the next.
The processor seems to work OK so I assume the ROMs are seated. I did re-seat them anyway. Thanks for the comments and now back to work :-) Bill K7NOM John Miles wrote: > It's normal for those last few digits to bounce around when measuring > frequency. The shorter the gate time, the less-consistent the LSDs will be. > How do the tolerances compare to what's in the manual's self-check > procedures? You'll note that they don't tell you to expect 10.000 000 000 > MHz, but 10.000 000 0XX MHz. > > The important things to look at with a 5370 are: 1) verify that the trigger > levels are 0.00 +/- 0.01 with the controls set to PRESET; 2) verify that the > +T.I. ONLY interval is within 1 ns of 100.0 ns; and 3) verify that the > jitter when measuring its own clock reference is less than 100 ps (all of > the ones I have seen are under 50.) If all of that is OK, then chances are > everything else will work properly including frequency measurement. > > I've found that many of them need their front-panel input assembly taken > apart and the switches carefully cleaned/lubed. That alone may clear up a > lot of flakiness. There have also been some reports of poorly-seated ROMs, > and/or socket contact problems. > > -- john, KE5FX > > > >> I got a HP 5370A off of Ebay and although it looks terrible I thought it >> would probably work OK. >> But it doesn't :-( I downloaded the manual and have yet to print it out. >> >> Question; >> When doing a self check by feeding the 10 MHz from the back into the >> counter it counts cycles OK >> but the last 3 or 4 digits are erratic. I am starting to do as much >> alignment as I can but am >> wondering if this is a known problem and if a cure is known. >> >> Anyway I think I paid too much for this box of problems but will >> continue to try to repair. >> >> Any suggestions (on repair only) is appreciated >> >> Bill K7NOM >> >> > > > _______________________________________________ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > > _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
