Tektronix 492 Service Manual

*1
492/492P Service Vol. I (SN B030000 & up)
TABLE OF CONTENTS (cont)
Page Page
Section 4 MAINTENANCE (cont) Section 4 MAINTENANCE (cont)
Repairing the Crt Trace Rotation
7. Check and Calibrate
Coil .................................................
4-14
Tune Sensitivity..........................
4-34
Front Panel Assembly ....................
4-14
8 . Conclusion .................................
4-34
Front Panel Board..........................
4-14
Troubleshooting Aids for the 2182 MHz
Replacing Front-Panel Push Button
Phaselocked 2nd LO ...........................
4-35
Switches .........................................
4-15
MICROCOMPUTER SYSTEM
Main Power Supply Module ............
4-15
MAINTENANCE .................................
4-36
High Voltage Power Supply ............
4-16
Memory Board Option Switch ........
4-36
Replacing the 1st (YIG) Local
Power-Up Self-Test Mode ..............
4-37
Oscillator Interface Board ................ 4-16
Microcomputer Test Mode ..............
4-38
Compliant Mounted Fan .................. 4-16
Instrument Bus Check Mode ..........
4-39
MAINTENANCE ADJUSTMENTS
4-19
Firmware Operating Notes ..............
4-39
110 MHz IF Assembly Return Loss
Exceptions for Firmware
Calibration .......................................
4-19
Version 8 .2 .....................................
4-40
2072 MHz 2nd Converter ..........
4-19
Exceptions for Firmware
Four Cavity Filter ........................
4-20
Versions 8.2, 8.7 and 8 . 8 ................
4-41
M ixer .........................................
4-20
Exceptions for Firmware
110 MHz Three Cavity Filter
4-20
Version 1.1 (492P only) ..................
4-41
829 MHz Converter Maintenance ........
4-21
Exceptions for Firmware
1. To gain acceses to the LO
Versions 1.1 and 1.2 in 492P only ..
4-42
section........................................
4-21
Changes incorporated in
2. To gain access to the IF
Version 1.2 Firmware......................
4-42
section .......................................
4-21
TROUBLESHOOTING ON THE
3. 719 MHz Oscillator Range
INSTRUMENT BUS ............................
4-42
Adjustment ................................
4-21
Instrument Bus Data Transfers
4-42
4. 829 MHz Coaxial Bandpass Filter
Instrument Bus Registers ................
4-45
Adjustment ................................
4-22
Troubleshooting and Calibrating
the 2182 MHz Phaselocked 2nd LO ...
4-25
Oscillator Section ................................
4-27
1. Preparation ................................
4-27
Section 5 THEORY OF OPERATION
2. Adjust and Check Functional and General Description ... 5-1
Oscillator Frequency ..................
4-27
Detailed Description
5-3
3. Measure Output Power ..............
4-28
1 st Converter .................................
5-3
4. Check the 2200 MHz
RF Interface Circuits ..................
5-4
Reference Mixer ........................
4-29
RF Circuitry ...............................
5-5
5. Check Tune Range ....................
4-29
2nd Converter ................................. 5-6
6 . Reassembly................................
4-29
2072 MHz 2nd Converter .......... 5-8
Troubleshooting and Calibrating 2182 MHz Phaselocked
the 14-22 MHz Phaselock Section
2nd LO .......................................
5-10
of the 2nd LO Assembly ......................
4-30
General Description ................ 5-10
1. Preliminary..................................
4-31
2182 MHz Microstrip
2. Check Voltages..........................
4-31 Oscillator ............................... 5-10
3. Check Tune Linearity ..................
4-31
2200 MHz Reference Board .. 5-11
4. Coarse Linearity Adjustment....
4-32
2200 MHz Reference Mixer .. 5-11
5. Fine Linearity Adjustment ..........
4-33
14-22 MHz Phaselock Board . 5-11
6 . Set the Center Frequency Cavity 2nd LO Local Oscillator..
5-12
of the 14-22 MHz Oscillator ....
4-34
829 MHz 2nd Converter ............
5-13
REV JUN 1.983
iii

Tektronix 492 Specifications

General

Brand	Tektronix
Model	492
Category	Measuring Instruments
Language	English