HP 8444A - Page 24

Operation
Figure 3-10 illustrates frequency measurement at
the 30 dB point on a low-pass filter,
a. Spectrum Analyzer (8554B) control
settings:
FREQUENCY 4% 6 od oobosbeeud sean D0 MHZ
BANDWIDTH cora iia 300 kHz
SCAN WIDTH PER DIVISION ........ 10 MHz
INPUT ATTENUATION .............. 10dB
SCAN TIME PER DIVISION 10 MILLISECONDS
LOG REF LEVEL . sisi 000222 cases a DB
LOG/LINEAR ............. pal Re Gea LOG
VIDEO BIETER... ge ds KA OFF
SCAN MODE 2... ale arene paa ts aka E
SCAN TRIGGER 2.3350 ena bate en ... AUTO
b. Tracking Generator control settings:
TRACK ADS nat .... Peak
EEN DONE EEE TEN 0 dBm
MANUAL SCAN |... sawa aata aa,
c. Connect unit under test between Tracking
Generator RF OUTPUT and Spectrum Analyzer
RF INPUT.
d. Connect Tracking Generator AUX RF
OUTPUT to Frequency Counter input.
e. Connect Tracking Generator SCAN
OUTPUT to Spectrum Analyzer SCAN IN/OUT.
f. Connect Tracking Generator FIRST LO
INPUT to Spectrum Analyzer FIRST LO OUTPUT
and THIRD LO INPUT to THIRD LO OUTPUT.
3-10
Model 84444
g. Note point of interest on CRT display.
h. Set Spectrum Analyzer SCAN MODE to
EXT and rotate Tracking Generator MANUAL
SCAN control clockwise to point of interest.
i. Note and record frequency.
j. Set Spectrum Analyzer SCAN MODE to
INT.
Note
The CRT trace (dot) can be moved in
either direction by the Tracking Genera-
tor MANUAL SCAN control. For best
frequency accuracy, approach frequency
measurement point while tuning the
MANUAL SCAN control in the clockwise
direction.
Figure 3-10. Precision Frequency Measurement
CRT Display