A7 Pulse Generator Check With Oscilloscope - HP 8753E Service Manual

Use a spectrum analyzer, to examin e the HI OUT signal from the Al4
2.
assembly. The signal should appear as clean as Figure 7-25. The comb shape
may vary from pulse generator to pulse generator.
Figure 7-25. Stable HI OUT Signal in FRACN TUNE Mode
Perform this check if a spectrum analyzer is not available.
1. Remove the A4to-All SMB cable from the A4 (R) sampler/mixer output.
Connect the oscilloscope to the A4 output (1st IF).
2. Activate the FRACN TUNE service mode and t.~e,,ne.~~~~ion~~,~ t@-,
3. Activate the SRC TUNE service mode of the analyzer and tune the source to
. . . . . . . . . . . . . .
4. Set the SRC TUNE frequency to those listed in Table 7-7 and observe the 1st
If the signals observed are proper, continue with "All Phase Lock Check".
q
perform the preceding "A7 Pulse Generator Check with Spectrum
Analyzer".
. .