Racal Instruments 3152, User Manual

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Maintenance and Performance Checks 5-20
Clock Synthesizer
Checkout
Problems with the clock synthesizer circuits can be detected if the
Model 3152 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 3152 to the
factory default using the *RST command and change frequency
setting to 1 MHz.
Table 5-3 Clock Synthesizer Checkout Procedure
Step Test Point Expected Result
1 U510 pin 7 100 MHz ECL level clock
2 U16 pin 15 50 MHz ECL level clock
3 U16 pin 2 25 MHz ECL level clock
4 U505 pin 21 1.5625 MHz TTL level clock
5 U506 pin 6 1.5625 MHz ECL level clock
6 U506 pin 2 1.5625 MHz square waves 2 Vp-p
7 U503 pin 1 1.5625 MHz ECL level clock
8 U503 pin 2 1.5625 MHz ECL level clock
9 Q502, Q503 collector 1.5625 pulses 3 Vp-p on 5 V offset
10 U516 pin 6 Approximately 12 VDC
11 U17 pin 15 100 MHz ECL level clock