Agilent Technologies 856290216 service manual Al5 RF Assembly, Confirming a Faulty Third Converter

Al5 RF Assembly

Note	The block diagrams for the Al4 and Al5 assemblies are located in Chapter 11,
	“Synthesizer Section.”

Confirming a Faulty Third Converter

1.Perform the “IF Input Amplitude Accuracy” performance test in the HP 8560 E-Series Spectrum Analyzer Calibration Guide. This exercises most of the third converter.

2.If the performance test fails, perform the “External Mixer Amplitude Adjustment” in Chapter 2, “Adjustment Procedures.”

3.If adjustment cannot be made, disconnect W35 (coax 92) from A15J801.

4.On the HP 85623, press c-1 and set the controls to the following settings:

Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..300MHz Span . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OHz

5.Connect a signal generator to A15J801.

6.Set the signal generator to the following settings:

Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..310.7MHz CW Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -28dBm

7.If a flat line is displayed within 2 dB of the reference level and the performance test passed, troubleshoot microcircuits A7, A8, A9, and A13.

8.If a flat line is displayed within 2 dB of the reference level and the performance test failed, troubleshoot the Al5 RF assembly.

9.Disconnect the signal generator from A15J801 and reconnect W35.

Confirming Third Converter Output

1.Connect the HP 85623 CAL OUTPUT to the INPUT 5Ofl connector.

2.Set the HP 85623 to the following settings:

Center frequency	..300MHz
Span ..,..........................................................0 Hz
Input attenuation	. . . . . 10 dB

3.Press [WSWP), (CAL), SF AD3 OFF.

4.Disconnect W29 (coax 7) from A15J601.

5.Connect a test cable from A15J601 to the input of another spectrum analyzer.

6.Tune the other spectrum analyzer to 10.7 MHz. The signal displayed on the other spectrum analyzer should be approximately -15 dBm.

7.Remove the test cable from A15J601 and reconnect W29 to A15J601.

12-18 RF Section