Tektronix 221 User manual

Tektronix, Inc.
P.O. Box 500
Beaverton, Oregon 97005
TEKTRO N IX
221
OSCILLOSCOPE
SERVICE
  

WARRANTY
Copyright (C) 1973, new material 1974, by Tektronix, 
Inc., Beaverton, Oregon. Printed in the United States of 
America. All rights reserved. Contents of this publication 
may not be reproduced in any form without permission of 
Tektronix, Inc.
All TEKTRONIX instruments are warranted against 
defective materials and workmanship for one year. Any 
questions with respect to the warranty should be taken up 
with your TEKTRONIX Field Engineer or representative.
All requests for repairs and replacement parts should be 
directed to the TEKTRONIX Field Office or representative 
in your area. This will assure you the fastest possible 
service. Please include the instrument Type Number or Part 
Number and Serial Number with all requests for parts or 
service.
Specifications and price change privileges reserved.
U.S.A, and foreign TEKTRONIX products covered by U.S. 
and foreign patents and/or patents pending.
TEKTRONIX is a registered trademark of Tektronix, Inc.


221 Service
    
SECTION 1
OPERATING INFORMATION
Page
SECTION 5 CALIBRATION (cont)
Page
AND SPECIFICATIONS
PRELIMINARY PROCEDURE 5-2
INTRODUCTION
1-1
PRELIMINARY CONTROL
ELECTRICAL
1-1
SETTINGS 5-2
Vertical Deflection System
1-1
INDEX TO CALIBRATION
Triggering
1-1
PROCEDURE
5-3
Horizontal Deflection System
1-2
POWER SUPPLY 5-4
Display
1-2
DISPLAY 5-6
Power
1-2
VERTICAL SYSTEM 5-7
PHYSICAL
1-3
SWEEP TRIGGER 5-11
HORIZONTAL SYSTEM 5-12
SECTION 2
FUNCTIONS OF CONTROLS
AND CONNECTORS
2-1
SECTION 6
TROUBLESHOOTING AIDS
SECTION 3
PREVENTIVE MAINTENANCE
Diagrams
6-1
Troubleshooting Equipment 6-1
Disassembly
3-1
Component Color Coding 6-2
Cleaning
3-1
Isolating Trouble To A Circuit 6-2
Visual Inspection 3-2
Semiconductor Checks 3-2
Recalibration
3-3
SECTION 7 CORRECTIVE MAINTENANCE
Obtaining Replacement Parts 7-1
SECTION 4 CIRCUIT DESCRIPTION
Component Replacement
7-1
Recalibration After Repair 7-2
BLOCK DIAGRAM 4-1
Instrument Repackaging
7-2
CIRCUIT OPERATION
4-1
Vertical Amplifier
4-1
SECTION 8
ELECTRICAL PARTS LISTS
8-1
Trigger Sweep
4-3
Horizontal Amplifier
4-5
Power Supply
4-6
SECTION 9
DIAGRAMS, CIRCUIT BOARD
CRT Circuit
4-8
ILLUSTRATIONS
SECTION 5 CALIBRATION
SECTION 10 MECHANICAL PARTS LISTS
10-1
TEKTRONIX FIELD SERVICE
5-1
TEST EQUIPMENT REQUIRED
5-1
CHANGE INFORMATION
      

Fig. 1-1. The Tektronix 221 Oscilloscope.
  


Section 1 — 221 Service
   
  
INTRODUCTION
               
               
               
             
          
                 
                 
                 
                 
        
           
               
               
                 
                 
                 
             
                 
                   
           
  
                     
             
                   
            
               
           
               
                       
                     
                 
      
ELECTRICAL
               
               
             
           
    
             
                    
                 
        
Vertical Deflection System
               
  
               
  
         
    
               
                 
      
          
              
      
        
                    
      
Triggering
  
                 
            
                 
          
               
    
          
  
        
        
                
                  
      
1-1

Operating Information and Specifications — 221 Service
Horizontal Deflection System
  
            
      
               
          
               
               
  
         
               
               
        
         
               
                 

    
               
    
             
  
Power
    
                             
            
      
          
  
               
                     
                     
  
             
                 
          
  
          
            
              
               
      
           
               
    
        
        
                    
      
         
    
Display

        
              
    
                 
                 
        
    
            
TABLE 1-1
CHARGE 
TEMPERATURE
OPERATING TEMPERATURE

+20° C to +30° C
+55° C
      
  
      
      



  
 

1-2       

Operating Information and Specifications — 221 Service
PHYSICAL

                 

                 
      
              

             
                 
  
      
               
    
             
                 
          
    
       
        
        
        
        

1-3
    

Section 2 — 221 Service
  
    
               
                     
                   
        
           
                 

             
                 
  
                
                 
    
           
               
  
               
            
               
                  
                 
                   
              
                     
    
                 
                     
                   
               
                 

               

           
               
             
  
               
               
              

Fig. 2-1 Side panel showing controls and connectors.
      
2-1

Functions of Controls And Connectors — 221 Service

Fig. 2-2. Side panel showing controls and connectors.
               
        
           
      
                   
                   
          
             
                     
                       
                   
                   
               
                   
      
             
            
              
            
      
             

             
            
           
               
               
          
             
                 
    
2-2
      

Section 3 — 221 Service
  
             
               
                   
               
               
             

Disassembly
                   
                     
                   
                 
            
                     
                 
                 
                   
  
Cleaning
                 
               
      
               
                   
                a     
                     
                   
                     
               
  
               
                         
                   
                   
              
Avoid the use of chemical cleaning agents which 
might damage the plastics used in this instrument. 
Avoid chemicals which contain hydrochloric acid, 
sodium hydroxide, or sulfuric acid.
Fig. 3-1. Location of screws securing bottom cover and side panel 
(instrument shown upside down).
    
3-1

Preventive Maintenance — 221 Service
Visual Inspection
               
             
               
               
               
             
                 
                 

Semiconductor Checks
               
             
               
                 
                 
               
                 
        
                 
                 
                     
                   
                     
                   
               
                   
            







  
   







  
 




   

Fig. 3-2. Lead configurations of the semiconductors used in the 221 Oscilloscope.
3-2
    


Preventive Maintenance — 221 Service
Recalibration
             
                  
                 
               
               
                 
                   

3-3

Section 4 — 221 Service
CIRCUIT DESCRIPTION
               
                   
               
                 
                     
    
Vertical Amplifier
               
               
                 
                   
          
BLOCK DIAGRAM
                     
                   
             
           
  
             
                   
                 
                   

               
                 
                 
                 
               
  
               
                
                   
                 

CIRCUIT OPERATION
                 
                     
                   
                 
        
         
      
                   
                 
                 
                   
                 
                   
           
                   
           
         
            
               
                 
                 
                   
             
                 
                 
      
             
                   
                   
               
                 
                 
             
             
                   
               
               
               
             
               
                 
  
       4-1

Circuit Description — 221 Service
Fig. 4-1. Simplified block diagram of the Vertical Amplifier circuit.
                   
           
             
                 
             
                 
               
             
                   
  
                 
                   
               
               
                 
                 
                 
          
              
               
               
                   
            
               
                    
                              
                   
              
4-2
      

Circuit Description — 221 Service
   

Fig. 4 2. Simplified block diagram of the Trigger Sweep circuit.
Trigger/Sweep
                
               
                   
                   
                 
                
                 
               
                   
                   
                   
                 
                   
                     
             
                   
                       
      
              
                 
                     
             
                   
                 
                     
               
             
             
             
                    
                       
                   
        
      
4-3

Circuit Description — 221 Service
               
               
               
                   
                
               
                   
                   
               
  
               
                 
                   
                   
                   
                 
               
                   
                   
                     
                   
                     
                   
                 
                 
                 
                     
                 
               
                     

               
               
                   
                 
              
                 
               
               
                 
                 
          
                 
                      
                 
                 
                   
                 
    
4-4
      

Circuit Description — 221 Service
Fig. 4-3. Simplified block diagram of the Horizontal Output Amplifier circuit.
Horizontal Amplifier
           
                       
                     
                     
          
               
               
             
               
                 
        
                 
               
                     
               
                         
                        
                 
               
                      

                 
                
                
          
                 
             
                 
               
             
                 
    
             
                 
                 
                     
             
               
          
      
4-5

Circuit Description — 221 Service
The circuit from the power line to the primary of 
T633 is floating at line potential. Any signal 
measurement in this circuit must be referenced to 
pin 1 of T633, and should be measured only if an 
Isolation transformer is used on the power line.
Power Supply
                 
                    
                     
                     
      
                 
                   
                     
               
                    
                   
             
                   
                
                 
                   
                   
                 
                   
               

4-6       

Circuit Description — 221 Service
                   
                   
               
                 
               
                   
                   
                   
                   
                     
               
               
                   
                     
                   
  
                    
                 
                 
                 
               
                 
                 
                 
                 
                   
               
          
               
                 
                        
               
    
               
             
                     
               
       
                 
                 
                    
             
                 
                   
                     
                   
                     
                 
               
                     
                   
        
      
4-7

Circuit Description — 221 Service
Fig. 4-5. Simplified block diagram of the CRT circuit.
CRT Circuit
                 
                   
                       
      
               
                   
                 
                     
                   
                      
                  
                   
    
                 
                 
                 
               
                       
             
             
                 
                 
             
               
             
    
4-8
      