quency control to position the high (or low) car-
rier at the center of the display.Note the
frequency reading.
j. On the keyboard, enter 1to toggle the polarity.
k. Now,adjust the center frequency control to po-
sition the low (or high) carrier at the center of
the display.Note the frequency reading.
l. The difference between these two frequencies
should be 200 MHz ±8 MHz. If not, enter 2
and fine adjust the DAC to obtain this devia-
tion.
m.When finished setting the DAC, press Qon the
keyboard to return to the menu then enter 3to
go to the next calibration step (adjusting the
DAC to obtain 20 MHz deviation).
n. On the keyboard, enter 2, then press the 1key
to start calibration.
o. While oberving the Spectrum Analyzer display,
adjust the value of the DAC’ssetting to obtain
a 10 MHz change in frequency.
p. On the keyboard, press Qto return to the
menu, then enter 1to toggle the polarity.
q. Measure the change in frequency on the Spec-
trum Analyzer.The change in frequency
should be 20 MHz. If not, enter 2and adjust
the DAC.
r. Repeat steps 5.p and 5.q as necessary to obtain
a 20 MHz frequency change. When finished ad-
justing the DAC, press Qto return to the
menu.
s. On the Spectrum Analyzer, set the Span/Div to
1 MHz per division and adjust the center fre-
quency control to position the high (or low) car-
rier at the center of the display.Note the
frequency reading.
t. On the keyboard, enter 1to toggle the polarity.
u. Now,adjust the center frequency control to po-
sition the low (or high) carrier at the center of
the display.Note the frequency reading.
v. The difference between these two frequencies
should be 20 MHz ±0.8 MHz. If not, enter 2
and fine adjust the DAC to obtain this devia-
tion.
4-42 682XXB/683XXB MM
FM
CALIBRATION CALIBRATION