HP 8753E Service Manual

2. Use a spectrum analyzer, to examin e the HI OUT signal from the Al4
assembly. The signal should appear as clean as Figure 7-25. The comb shape
may vary from pulse generator to pulse generator.
sg626s
Figure 7-25. Stable HI OUT Signal in FRACN TUNE Mode
A7 Pulse Generator Check with Oscilloscope
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@-, .._.................................. ,.,, _ . . . . . . _ . . . . . _ ;... _
_ . . . i_ _ __.....i . . .,.
_ ..; ..,., ..,.,...
_. ,.
_
50 MHz. press Is-] ~~~~~~~~ ~~~~~~~~~~ ~~~:~,~~~~.~~~~ [sol
m-
3. Activate the SRC TUNE service mode of the analyzer and tune the source to
,:: 7 .i .:z: .~~;.;~~~~;.~~~;~;;;~~; ii
50 M&. press ~~~~.~.~~~~~ ~~~~~~~ L50) Irln_llE).
i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _
._ _ _ _ . . . . . __ _ __ ____ _ .,.,.,.,. i _ _ ,.,. _.,._.,_.~.._
4. Set the SRC TUNE frequency to those listed in Table 7-7 and observe the 1st
Il? waveforms. They should appear similar to F’igure 7-26.
q If the signals observed are proper, continue with “All Phase Lock Check”.
~3 If the signals observed are questionable, use a spectrum analyzer to
perform the preceding “A7 Pulse Generator Check with Spectrum
Analyzer”.
7-34 Source Troubleshooting

HP 8753E Specifications

General

Brand	HP
Model	8753E
Category	Measuring Instruments
Language	English