Chapter 12
615
RF Section
A14 Frequency Control Assembly
Control Latch for Band-Switch Drivers
Refer to function block P on A14 Frequency Control Schematic Diagram
in the 8560 E-Series Spectrum Analyzer Component Level Information.
1. Connect the positive lead of a DVM to A14U417 pin 14
(LLOWBAND) and the negative lead to A14J18 pin 6.
2. Set the spectrum analyzer to the following settings:
Center frequency .................................................. 300 MHz
Span .............................................................................. 0 Hz
3. The voltage should measure approximately 0 Vdc (TTL low).
4. Set the spectrum analyzer center frequency to 3 GHz.
5. The voltage should measure approxi5 Vdc (TTL high).
6. Move the positive lead of the DVM to A14U406 pin 12 (LSBTX).
7. The voltage should measure approxi5 Vdc (TTL high).
8. Set the spectrum analyzer center frequency to 35 GHz.
9. The voltage should measure approximately 0 Vdc (TTL low).
YTF Driver Circuit
The YTF driver circuitry consists of the Sweep + Tune Multiplier, FAV
(Frequency Analog Voltage) Generator, YTF Gain and Offset, and YTF
Drive. Refer to function blocks Q, R, S, and T on A14 frequency control
schematic diagram. The FAV generator generates the 0.5 V/GHz signal.
The YTF driver circuitry can be half-split by checking the rear panel
FAV OUTPUT.
NOTE
The rear panel output changes according to the external-mixer mode
selected. The preselected external-mixer mode must not be selected
while executing this procedure. Make sure that the rear panel output is
set for .50 V/GHz and not .25 V/GHz.
The Sweep + Tune Multiplier takes tune information (YTO start
frequency) and sweep (based on LO span) and multiplies it so that it is
correct for the appropriate YTF band.
C31 of the FAV Generator holds the YTF steady during retraces
between multiband sweeps. Switch U606C and R94 provide the YTF
dehysteresis pulse. A dehysteresis pulse is activated at the end of spans
greater than 1 MHz. In microwave bands, amplifier U402A provides an
offset voltage to account for the 310.7 MHz offset (U415A open) between
the desired harmonic of the YTO frequency and the center frequency. In
low band, switch U415A is closed to account for the negative
3.9107 GHz 1st IF offset between the YTO frequency and the center
frequency. In millimeter bands, U415D is closed to account for the
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 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 ...
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Page 287: ...377 8 ADC Interface Section ...
Page 291: ...Chapter 8 381 ADC Interface Section Introduction Figure 8 2 A3 Test Connector Pin Locations ...
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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 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 ...
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Page 492: ...633 13 Display Power Supply Section ...
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Page 505: ...671 14 Component Level Information Packets ...
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