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Characteristic
Tube Type
Phosphor
Accelerating Potential
Graticule Type
Area
Illumination
U n b l i n k i n g
TIME BASE
Characteristic
Performance Requirement
S u p p l e m e n t a l I n f o r m a t i o n
,
RECORDER Output
≥4
mV per displayed division amplitude of
Rear panel connector
signal in LIN made.
Sweep Range
10
µs/div to 0.5
s/div
In a 1, 2, 5 sequence
Sweep Accuracy
± 3 %
Measured within the center 8 divisions
V A R I A B L E T i m e / D i v
≥ 2 . 5 : 1
An uncalibrated control provides continu-
ously variable sweep rates from 10 µs/div
to approximately 1.25 s/div.
Sweep Length
10.5 divisions ±0.2 div.
Sawtooth Output
70 mV to 90 mV (P-P)
Rear panel connector
TRIGGERING
Trigger Sensitivity
Internal
≤0.2
division, 20 Hz to 100 kHz
External
≤0.2
volt, 20 Hz to 100 kHz
Maximum Input Voltage
100 volts (DC + peak AC)
POWER REQUIREMENTS
Input Voltage
115-volt range
LOW- 90 to 110 VAC
MED- 104 to 126 VAC
H I G H - 1 1 2
to
1 3 6 V A C
Line voltage ranges provide regulated DC
230-volt range
LOW- 180 to 220 VAC
voltages, when line contains less than 2%
MED- 208 to 252 VAC
total harmonic distortion.
HIGH- 224 to 272 VAC
Line
Frequency
48 to 440 Hz
Input Power
55 watts maximum
CATHODE RAY TUBE
I n f o r m a t i o n
T4910-7-1
P7
Approximately 3.75 kV
internal
8 divisions vertical by 10 divisions horizontal
Construction
Finish
Overall Dimensions [measured
at maximum points]
Each division equals 0.8 cm.
Variable edge lighting
Deflection type, DC coupled
MECHANICAL CHARACTERISTICS
Alluminum-alloy chassis, panel and cabinet
Glass laminate etched-circuit boards
Anodized panel, blue vinyl-coated cabinet
7 ¼ ” h i g h , 1 2 ½ " w i d e , 2 3 ½ ” l o n g ( i n c l u d e s
ENVIRONMENTAL
The following environmental test limits apply when tested
in accordance with the recommended test procedure. This
instrument will meet the electrical performance requirements
given in this section, following an environmental test.
panel cover and carrying handle)
CHARACTERISTICS
1-3
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 ...
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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 ...