448
Chapter 9
IF Section
Log Amplifier (P/O A4 Assembly)
4. Set the oscilloscope controls as follows:
Amplitude scale ................................................... 200 mV/div
Offset ........................................................................ +400 mV
Coupling ............................................................................... dc
Sweep time ....................................................... 50
µ
s/division
5. The oscilloscope should display a 4.8 kHz sine wave.
6. Disconnect the cable from the CAL OUTPUT and the INPUT 50
Ω
connectors.
7. Set the resolution bandwidth to 2 MHz.
8. Broadband noise should be displayed on the oscilloscope from
approxi200 mV to +400 mV.
9. As the
REF LVL
is decreased in 10 dB steps from
−
10 dBm to
−
70 dBm, the noise displayed on the oscilloscope should increase in
100 mV increments. If this response is not observed, refer to
10.Reconnect cable W54 to A4J4.
Frequency Counter Prescaler/Conditioner
Refer to function block Q of A4 log amplifier schematic diagram (sheet
4 of 4) in the 8560 E-Series Spectrum Analyzer Component Level
Information
.
The frequency counter prescaler/conditioner divides the frequency by
two, and then attenuates it. The circuit consists of frequency divider
(U703A) and an output attenuator. The frequency divider turns on only
when the instrument is counting.
AM/FM Demodulator
Refer to function block R of A4 Log Amplifier Schematic Diagram (sheet
4 of 4) in the 8560 E-Series Spectrum Analyzer Component Level
Information.
The demodulator circuitry on the log amplifier on A4 produces a
low-level audio signal. This audio signal is then amplified by the audio
amplifier on A4. The FM demodulator demodulates narrowband FM
(5 kHz deviation) signals. The detector (block J) demodulates AM
signals.
1. If demodulation problems occur when the spectrum analyzer is in
the frequency domain, perform the Frequency Span Accuracy
performance test and, if necessary, the YTO Adjustments procedure.
Summary of Contents for 8564EC
Page 17: ...25 1 General Information ...
Page 37: ...47 2 Adjustment Diagnostic Software ...
Page 77: ...89 3 Manual Adjustment Procedures ...
Page 129: ...161 3a Manual Adjustment Procedures 3335A Source not Available ...
Page 142: ...175 4 Assembly Replacement ...
Page 194: ...Chapter 4 257 Assembly Replacement Procedure 13 A21 OCXO Figure 4 34 A21 OCXO Mounting Screws ...
Page 196: ...259 5 Replaceable Parts ...
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Page 223: ......
Page 224: ...303 6 Major Assembly and Cable Locations ...
Page 234: ...315 7 General Troubleshooting ...
Page 238: ...Chapter 7 319 General Troubleshooting Introduction Figure 7 2 Ribbon Cable Connections 1 of 3 ...
Page 239: ...320 Chapter7 General Troubleshooting Introduction Figure 7 3 Ribbon Cable Connections 2 of 3 ...
Page 242: ...Chapter 7 323 General Troubleshooting Introduction Figure 7 5 Service Cal Data Menu ...
Page 271: ...352 Chapter7 General Troubleshooting Block Diagram Description Figure 7 6 Functional Sections ...
Page 283: ...364 Chapter7 General Troubleshooting Block Diagram Description ...
Page 284: ......
Page 285: ......
Page 286: ......
Page 287: ...377 8 ADC Interface Section ...
Page 291: ...Chapter 8 381 ADC Interface Section Introduction Figure 8 2 A3 Test Connector Pin Locations ...
Page 321: ......
Page 322: ...427 9 IF Section ...
Page 356: ...Chapter 9 461 IF Section A5 IF Assembly Figure 9 13 Detailed IF Adjust Signature 5 ...
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Page 379: ...487 10 Controller Section ...
Page 394: ...521 11 Synthesizer Section ...
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Page 453: ......
Page 454: ...593 12 RF Section ...
Page 489: ...628 Chapter12 RF Section A15 RF Assembly Figure 12 10 10 MHz TTL Reference at U304 Pin 13 ...
Page 491: ......
Page 492: ...633 13 Display Power Supply Section ...
Page 504: ......
Page 505: ...671 14 Component Level Information Packets ...
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