Fig. 6-38. Equipment setup to adjust wide band IF amplifier and check flatness.
Type 491
F I N E R F C E N T E R F R E Q
Centered
I N T E N S I T Y
F O C U S a n d A S T I G M A T I S M
SCALE ILLUM
POSITION (Horizontal and
Vertical]
T I M E / D I V
VARIABLE
TRIGGER
SLOPE
LEVEL
S O U R C E
D I S P E R S I O N R A N G E
D I S P E R S I O N - C O U P L E D
R E S O L U T I O N
I F A T T E N U A T O R d B
IF CENTER FREQ Controls
V I D E O F I L T E R
V E R T I C A L D I S P L A Y
G A I N
P O W E R
M I X E R P E A K I N G
PHASE LOCK Controls
Display of nominal
brightness
I N T R E F F R E Q
O N
Adjusted for optimum
Test Oscilloscope
display definition.
T i m e / C m
1 ms
As desired
V o l t s / C m
. 0 0 5
A d j u s t e d f o r a h o r i z o n -
Input Coupling
AC
tally centered sweep on
Trigger
Int
the graticule baseline
20 ms
CAL
+
F R E E R U N
I N T
M H z / D I V
5 M H z / D I V
20 dB switch on
Midrange (000)
O F F
L I N
M i d r a n g e
O N
Manual
36. Adjust the Wide Band Amplifier
o
Response and Check the System Response
Flatness
N O T E
T h e T y p e 4 9 1 r e s p o n s e f l a t n e s s a n d s e n s i t i v i t y
i s d e p e n d e n t o n t h e c o m b i n e d r e s p o n s e o f t h e
w i d e b a n d a m p l i f i e r , t h e b a n d p a s s f i l t e r , t h e l o w
p a s s f i l t e r s a n d t h e R F m i x e r . E a c h c i r c u i t a s s e m -
b l y m u s t b e a d j u s t e d a s p a r t o f t h e c o m p l e t e
system, since the circuit response for each unit is
d e p e n d e n t o n t h e i m p e d a n c e p r e s e n t e d b y t h e
p r e c e d i n g a n d f o l l o w i n g c i r c u i t .
T h e l o w - p a s s a n d b a n d p a s s f i l t e r s s h o u l d r e q u i r e
r e c a l i b r a t i o n o n l y a f t e r c i r c u i t c o m p o n e n t s h a v e
been replaced.
I f r e c a l i b r a t i o n i s r e q u i r e d , t h e
a n a l y z e r s h o u l d b e r e t u r n e d t o T e k t r o n i x f o r c a l i -
6 - 3 6
Summary of Contents for 491
Page 4: ...i i Fig 1 1 The Type 491 Spectrum Analyzer ...
Page 24: ...2 16 Fig 2 17 Control set up chart ...
Page 34: ...Fig 3 1 Function block diagram of the Type 491 3 2 ...
Page 42: ...Fig 3 10 Block diagram of the video detector and vertical amplifier 3 1 0 ...
Page 48: ......
Page 53: ...Fig 4 4 Power Supply Circuit board assembly with wiring color code 4 5 ...
Page 54: ...Fig 4 5 Horizontal Display circuit board assembly showing color code to pin connectors 4 6 ...
Page 55: ...Fig 4 6 IF Control board assembly Wiring color code to pin connector 4 7 ...
Page 64: ...Fig 4 20A Tube subassembly removal procedure 4 16 ...
Page 65: ...Fig 4 20B Tube subassembly installation procedure 4 17 ...
Page 68: ...Fig 4 22 Power supply board assembly with component call out 4 2 0 ...
Page 69: ...Fig 4 23 Vertical Amplifier and Blanking board assembly with component call out 4 21 ...
Page 70: ...Fig 4 24 IF control board assembly with component call out 4 22 ...
Page 71: ...Fig 4 24 IF control board assembly with component call out 4 23 ...
Page 72: ...Fig 4 25 Horizontal display board with component call out 4 24 ...
Page 73: ...Fig 4 25 Horizontal display board with component call out 4 25 ...
Page 74: ...Fig 4 26 Phase lock board with component call out 4 26 ...
Page 88: ......
Page 90: ...Fig 6 1 Test equipment recommended for calibration of the Type 491 6 2 ...
Page 138: ......
Page 192: ......
Page 195: ...SECTION II B 3 ...
Page 196: ......
Page 200: ......
Page 201: ...SECTION 9 DIAGRAMS MECHANICAL PARTS LIST ILLUSTRATIONS ACCESSORIES ...
Page 202: ......
Page 203: ...9 1 ...
Page 204: ...9 3 ...
Page 205: ...9 5 ...
Page 206: ...9 7 ...
Page 207: ...9 9 ...
Page 208: ...9 11 ...
Page 209: ...9 13 ...
Page 210: ...9 15 ...
Page 211: ...9 17 ...
Page 212: ...9 19 ...
Page 213: ...9 21 ...
Page 214: ...9 23 ...
Page 215: ...9 25 ...
Page 216: ...9 27 ...
Page 217: ...FIG 1 9 29 ...
Page 218: ...FIG 2 REAR 9 31 ...
Page 219: ...9 33 FIG 3 IF CHASSIS PHASE LOCK ASSEMBLIES ...
Page 220: ...FIG 4 POWER CHASSIS 9 35 ...
Page 221: ...FIG 5 TIME DIV SWITCH OSCILLATOR ASSEMBLIES 9 37 ...
Page 222: ...FIG 6 CRT SHIELD ASSEMBLY 9 39 ...
Page 223: ...FIG 7 CABINET ASSEMBLY HANDLE 9 4 1 ...
Page 224: ...FIG 8 491 STANDARD ACCESSORIES FIG 8 491 STANDARD ACCESSORIES 9 43 ...
Page 225: ......
Page 226: ...PIN 028017 000 ...