[time-nuts] HP 5370B Questions

Ed Palmer ed_palmer at sasktel.net
Mon Mar 4 16:42:15 EST 2013

The recent thread on the 5370B resolution reminded me of a couple of 
questions I have about my unit.  Mine has a bit of a noise problem so I 
thought I'd work through the operator verification tests and a couple of 
the diagnosic flowcharts and see what popped up.  The results turned out 
to be more confusing than enlightening.

In the Operator Verification tests on page 3-12, the format of the 
frequency readings in step 19 don't match the resolution shown in the 
specifications on page 1-3.  The values in Step 19 seem to have one less 
digit than they should have.  e.g.  for the 1 sec. interval they show a 
target of 10.000 000 0XX MHz while my unit displays 10.000 000 000 X 
MHz.  The other values are also short a digit.  Is this a typo in the 

When I was working through Figure 8-18 (DAC/N0 Logic flowchart), Box 
number 50 towards the left-center of the figure states that I should see 
a result of 10.001 630 MHz.  I don't understand where this number comes 
from since the test is measuring the 10 MHz Ref Out signal.  In any 
case, I'm getting a reading of 10.001 512 MHz.  Is this better than 
spec, worse, or just wrong?

My unit has a serial number prefix of 2732.  The manual is for prefix 
2904.  I looked at the manual backdating pages but didn't see anything 
to explain these items.


More information about the time-nuts mailing list