Shaper DAC
Adjustment For Models 682XXB with Firmware Version
2.39 and above; Models 683XXB with Firmware
Version2.46 and above; Models 682X5B with
Firmware Version1.28 and above; and Models
683X5B with Firmware Version1.32 and above.
The following step in the procedure adjusts the
Switch Filter Shaper DAC which controls the gain of
the Switched Filter Shaper Amplifier.Each fre-
quency band will be scanned for the minimum un-
leveled power point before automatic adjustment of
the shaper DAC.
1. At the $prompt on the PC display,type:
calterm 138 and press <ENTER>. (The $
prompt will appear on the screen when the cali-
bration is complete.)
NOTE
The calibration routine may take up to 20
minutesdepending on the frequency range
of the 682XXB/683XXB being calibrated.
2. Storethe calibration data in non-volatile memory
(EEPROMs) on the A17 CPU PCB as follows:
a. Type:calterm 787 and press <ENTER>.
(The $prompt will appear on the screen when
the data has been stored.)
b. Record step completion on the Test Record.
682XXB/683XXB MM 4-21
SWITCHED FILTER
CALIBRATION SHAPER CALIBRATION
CAUTION
Whensaving calibration data, turn-
ing off the instrument before the $
prompt returns to the screen can
cause all stored data to be lost.