Chapter 3 3-27
Adjustments and Correction Constants
Cavity Oscillator Frequency Correction Constants (Test 54)
1. Connect the equipment shown in Figure 3-10.
Figure 3-10 Setup for Cavity Oscillator Frequency Correction Constant
Routine
2. Press
.
During this adjustment routine, you will see several softkeys:
3. Press to sweep the first frequency span three times. Each new span
overlaps the previous span by 3 MHz (the center frequency increases by 2 MHz; the
span is 5 MHz). Therefore, anything visible on the right half of the screen of one set of
sweeps will appear on the left half or center of the screen when you press .
4. Press repeatedly. Watch the trace on each sweep and try to spot the target spur.
With the filter, the target spur will be one of two obvious spurs (see Figure 3-11).
Without the filter (not recommended), the target spur will be one of four or five less
distinct spurs as shown in Figure 3-12 and Figure 3-13. When the center frequency
increases to 2994.999 MHz, and you have not “selected” the target spur, the message
Cav Osc Cor FAIL will appear on the display.
sweeps the current frequency span; you may
press it repeatedly for additional sweeps of the
current frequency span.
sweeps the next frequency span (2 MHz higher).
enters the value of the marker (which you have
placed on the spur) and exits the routine.
exits the routine.
Preset Avg
x1 System
54
x1
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