22. Frequency Reference Error
10 MHz Standard Adjustment
Aging Rate:
X
and
X
year; attained after 30
days warm-up from cold start at
Temperature Stability:
X
to 55°C
Frequency is within 1 X
of final stabilized frequency within 30
minutes.
The frequency of the spectrum analyzer time base oscillator is
measured directly using a frequency counter locked to a frequency
reference which has an aging rate less than one-tenth that of the
time base specification. After a 30-day warm-up period, a frequency
measurement is made. The analyzer is left undisturbed for a 24-hour
period and a second reading is taken. The frequency change over this
24-hour period must be less than one part in
This test requires that the spectrum analyzer be turned on (not in
STANDBY) for a period of 30 days to ensure that the frequency
reference attains its specified aging rate. However, after the aging
rate is attained, the frequency reference typically attains its aging
rate again in 72 hours of operation after being off for a period not
exceeding 24 hours.
Because the frequency reference is sensitive to shock and vibration,
care must be taken not to disturb the spectrum analyzer during the 24
hour period in which the frequency measurement is made.
The frequency reference should remain within its attained aging
rate if: the instrument is left on; the instrument orientation with
respect to the earth’s magnetic field is maintained; and the instrument
does not sustain any mechanical shock. Frequency changes due to
orientation with respect to the earth’s magnetic field and altitude
changes will usually be nullified when the instrument is returned to
its original position. Frequency changes due to mechanical shock will
usually appear as a fixed frequency error.
The frequency reference is also sensitive to temperature changes;
for this reason, the ambient temperature near the instrument at the
first measurement time and the ambient temperature at the second
measurement time should not differ by more than
Placing the
spectrum analyzer in STANDBY turns the instrument off while
continuing to provide power for the frequency reference oven, which
minimizes warm up time. However, the spectrum analyzer must be ON
to allow the frequency reference to attain its specified aging rate.
Performance Tests
Содержание HP 8566B
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Страница 137: ...Test 19 1st LO Output Amplitude Steps Min Measured Max 4 1st LO OUTPUT Level 5 dBm 2 112 Performance Tests ...
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Страница 351: ...23 Track and Hold Adjustments 25 Repeat steps 4 through 24 until no further adjustments are required Adjustments 3 211 ...
Страница 404: ...AIVI Wi AlAl ti2 W8 Figure 6 6 IF Section Front View 6 8 Major Assembly and Component locations ...