Anritsu 682XXB - Manual (Page 69)

Test
Procedure The frequency error is measured at the start and
finish of the test time period of 24 hours. The aging
rate is the difference between the two error read-
ings.
1. Set up the Frequency Reference as follows:
a. Press the ESC key until the MAIN MENU is
displayed.
b. At the MAIN MENU display, press 1 to select
CONFIGURATION.
c. At the CONFIGURATION MENU display,
press 8 to select MEAS.
d. Press the MOD key and use the Up/Down Ar-
row keys to get to the menu display:
MEASUREMENT = FREQ.
e. Press the ENTER key.
f. Press the ESC key until the MAIN MENU is
displayed.
g. At the MAIN MENU display, press 3 to select
the REVIEW MENU.
h. At the REVIEW MENU display, press 8 to se-
lect TFM.
2. Connect the 682XXB/683XXB rear panel 10 MHz
REF OUT signal to the Frequency Reference front
panel 10 MHz input.
3. Wait approximately 90 minutes (default setting)
until the FMFOM on the Frequency Reference
display decreases from 9 to 1. (The default setting
is recommended to achieve optimum mease-
ments.)
The frequency error in the signal under test is
displayed in ps/s (Picoseconds/Second). For exam-
ple, an error of –644681 ps/s is –644681
´ 10 –12
or
–6.44681
´ 10 –7
away from the 10 MHz internal
reference of the Frequency Reference.
The frequency error display is continuously up-
dated as a running 5000-second average. The av-
eraging smooths out the short-term instability of
the oscillator.
682XXB/683XXB MM 3-9
PERFORMANCE INTERNAL TIME BASE
VERIFICATION AGING RATE TEST