Chapter 9 465
IF Section
A5 IF Assembly
1 MHz Resolution Bandwidth Problems
Check the crystal shorting switches as follows:
1.On the 8564EC or 8565EC spectrum analyzer, press
PRESET
and set the controls as follows:
Resolution bandwidth .............................................. 1MHz
Span ....................................................................... 500kHz
Center frequency .................................................. 300MHz
2.On the 8564EC or 8565EC spectrum analyzer, connect the
300 MHz CAL OUTPUT to the INPUT 50Ω.
3. If the trace flatness is not within 2.5 dB, a failure probably exists.
4. A trace similar to Figure 9-18 on page 465 indicates a crystal short
failure.
5. Press
SPAN to set the spectrum analyzer to 3 MHz. A trace that
slopes across the screen (see Figure 9-19, “Faulty LC Pole”) indicates
a failed LC pole. To isolate the broken pole refer to the shape factor
information in “30 kHz Resolution Bandwidth Problems.”
Figure 9-18 Faulty Crystal Short
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