HP 8340B Manual page 471

HOW TO RESTORE FACTORY-OPTIMIZED CALIBRATION CONSTANTS
A printed copy of protected data is included with each instrument.
It is
stored
in
a
bracket
located
under the top cover, on the left side of the instrument
(as
viewed from
the front).
If
working and protected data in
RAM are
lost,
use the information on this
sheet
to restore the cal
constants.
When the instrument is recalibrated, the printed copy protected data
should be updated and placed
back
in
the instrument
(remember
to update protected data after recalibration). Figure A-3 shows an
example of
a
calibration
constant
printed copy.
1.
Remove
the top
cover
of the instrument. Inside the instrument, find the printed copy of calibration
constants
(they
are
in
a
metal bracket
on the left side of the instrument, as viewed from the
front).
2.
Replace the top cover.
V¥¥¥¥V¥¥¥¥^f
CCAUTIONJ
This procedure
affects data required for optimum instrument perfor¬
mance. Be careful when accessing or changing calibration data.
3.
To access the
calibration constants, press:
[SHIFT] [GHz] [1] [Hz]
[SHIFT] [MHz] [1] [2] [Hz]
[SHIFT] [KHz] [2] [2] [Hz]
The
value
of calibration constant
#1 is
displayed in the
ENTRY
display.
4.
Compare the value on the
ENTRY
display with the value
listed
in the print-out.
If
the values do not
match:
a.
Enter the value from the print-out
via
the DATA ENTRY keyboard.
b.
Press
[Hz].
5.
To see the next calibration constant, press the up
STEP
key.
6.
Repeat steps
4
and
5 until
all calibration constants are the same as those shown on the print-out.
7.
To
store the entered calibration constants into protected memory, press:
[SHIFT]
[MHz]
[1] [4] [Hz]
[SHIFT] [KHz] [5] [3] [4] [9] [Hz]
CALIBRATION STORED appears
in
the
ENTRY
display.
8.
Press [INSTR PRESET].
The FAULT
indicator should be
off. If it is still
on, suspect
a
problem with the instrument's mem¬
ory.
9.
Replace the print-out inside the instrument.
HP 8340B/41B
Assembly-Level Service Calibration Constants A-23