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3151 And 3151A User Manual
Maintenance and Performance Checks 5-22
Clock Synthesizer
Checkout
Problems with the clock synthesizer circuits can be detected if the Model
3151/3151A accepts word serial commands and responds correctly to word
serial queries, but fails to output the correct waveform frequency. If there is
a problem with the clock synthesizer circuit, proceed with the checkout
procedure given in Table 5-3.
Before you start with the following procedure, reset the 3151 to the factory
default using the *RST command.
Table 5-3, Clock Synthesizer Checkout Procedure
Step Test Point Expected Result
1 U15 pin 3 100 MHz ECL level clock
2 U16 pin 15 50 MHz ECL level clock
3 U16 pin 2 25 MHz ECL level clock
4 U32 pin 10 25 MHz TTL level clock
5 U31 pin 10, U32 pin 1 6.1035 kHz TTL level clock
6 U31 pin 1, U32 pin 10 1.49 Hz TTL level clock
7 U38 pin 3 46.56 MHz TTL level clock
8 U22 pin 8 10 MHz TTL level clock
9 U22 pin 3, U22 pin 13 Positive going pulses; 100 ns width, 400
F
s period
10 U14 pin 1 Approximately -2 VDC
11 U14 pin 7 Approxi2 VDC