11-8 Rf Section; Al3 Second Converter - HP 8560A Service Manual

Al3 Second Converter

Caution
The Al3 assembly is extremely sensitive to Electrostatic Discharge (ESD). For
further information regarding electrostatic cautions, refer to "Electrostatic
Discharge Information" in Chapter 1.
1.
Connect the HP 8560A CAL OUTPUT to INPUT 50ohm.
2.
Set the HP 8560A to the following settings:
C E N T E R F R E Q
SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Hz
3. Disconnect W35 from A13J2.
4.
Connect a test cable from A13J2 to the input of another spectrum analyzer.
5. Tune the other spectrum analyzer to 310.7 MHz. The signal displayed on the other
spectrum analyzer should be approximately -28 dBm.
6. Remove the test cable from A13J2 and reconnect W35 to A13J2.
7.
Disconnect W33 from A13J4 and connect W33 through a test cable to the input of
another spectrum analyzer.
8.
Tune the other spectrum analyzer to a center frequency of 600 MHz.
9. If a 600 MHz signal is not present, or its amplitude is less than -5 dBm, the fault is
probably on the Al5 RF Assembly.
10. Reconnect W33 to A13J4.
11. Connect a DVM's positive lead to A14J19 pin 15 and the negative lead to A14J19 pin 6.
12. If the DVM does not measure between +14.0 Vdc and i-15.0 Vdc perform the following:
a. Set the HP 8560A's (LINE) switch off and disconnect W13 from A14J12.
b. Set the HP 8560A's (LINE] switch on and set the analyzer to the following settings:
CENTER FREQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..300MHz
SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..l0 MHz
c. The voltage should measure +15 Vdc +/-0.2 V. If th e voltage measures outside this
limit, the Al4 Frequency Control Assembly is probably defective.
d. Set the HP 8560A's IUNE) switch off, reconnect W13 to A14J12, and set the (LINEI
switch on. Set the HP 8560A to the following settings:
CENTER FREQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .300 MHz
SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OHz
13. Move the DVM's positive lead to A14J19 pin 1. The voltage should measure between
-150 m Vdc and -900 mVdc. If the voltage measures outside this limit, measure the
voltages on A14J19 pin 2 and pin3.
14. The voltage on A14J19 pin 2 should be 150 mV to 200 mV more positive than on A14J19
pin 3. If the voltage difference is not within this limit, the Al3 Second Converter is
probably defective.
Reconnect W13 to A14J12.
15.

11-8 RF Section

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