Section 1—475
SPECIFICATION
Introduction
The 475 Oscilloscope is a wide bandwidth, portable
oscilloscope designed to operate in a wide range of
environmental conditions. The instrument is light in weight
and compact of design for ease of transportation, yet
capable of performance necessary for accurate high-
frequency measurements. The dual-channel, DC-to-200
megahertz vertical deflection system provides calibrated
deflection factors from 2 millivolts to 5 volts/division. The
bandwidth limiting switch reduces interference from signals
above about 20 megahertz for viewing low-frequency,
low-level signals.
The trigger circuits provide stable sweep triggering to
beyond the bandwidth of the vertical deflection system.
Separate controls are provided to select the desired mode of
triggering for the A and B sweeps. The A sweep can be
operated in one of three modes; automatic triggering,
normal triggering, or single sweep. A variable trigger holdoff
control provides the ability for A sweep to trigger in a
stable manner on aperiodic signals or complex digital
words. The horizontal deflection system has calibrated
sweep rates from .5 second to .01 microsecond/division. A
X I 0 magnifier increases each sweep rate by a factor of 10
to provide a maximum sweep rate of one nanosecond/
division in the .01 /is position. The delayed and mixed
sweep features allow the start of B sweep to be delayed a
selected amount from the start of A sweep to provide
accurate relative-time measurements. Calibrated X -Y meas
urements can be made with Channel 2 providing the vertical
deflection and Channel 1 providing the horizontal deflec
tion (T IM E /D IV switch fully counterclockwise and V E R T
MODE switch to CH 2). The regulated DC power supplies
ensure that instrument performance is not affected by
variations in line voltage and frequency. Maximum power
consumption of the instrument is approximately 100 watts.
The following instrument specifications apply over an
ambient termperature range of —15°C to +55° C unless
otherwise specified. Warm-up time for specified accuracies
is 20 minutes. The calibration procedure given in section 5,
if performed completely, will allow an instrument to meet
the electrical characteristics listed below.
V E R T IC A L D EFLECTIO N SYSTEM
Deflection Factor
Calibrated range is from 2 millivolts to 5 volts per
division in 11 steps in a 1-2-5 sequence. Accuracy is within
3%. Uncalibrated VAR control provides deflection factors
continuously variable between the calibrated settings. Ex
tends deflection factor to at least 12.5 volts per division in
the 5 volts/div position.
Frequency Response
Bandwidth in both Channel 1 and Channel 2 is DC to at
least 200 megahertz. Risetime is 1.75 nanoseconds or less.
The AC-coupled lower —3 dB point is 10 hertz or less (1
hertz or less when using a 10X probe). Vertical system
bandwidth with the BW L IM IT pushbutton pulled is
approximately 20 megahertz*
Chopped Mode Repetition Rate
Approximately one megahertz.
Input Resistance And Capacitance
One megohm within 2%, paralleled by approximately 20
picofarads.
Maximum Input Voltage
DC coupled: 250 V (DC + peak AC) or 500 V P-P AC at
1 kHz or less.
AC coupled: 500 V (DC + peak AC) or 500 V P-P AC at
1 kHz or less.
Cascaded Operation (CH 2 V E R T IC A L SIG N AL
O UT connected to CH 1 OR X )
Bandwidth is DC to at least 50 MHz with a sensitivity of
approximately 400 juV/division.
TR IG G E R IN G
Sensitivity
DC Coupled: 0.3 division internal or 50 millivolts
external from DC to 40 megahertz, increasing to 1.5
divisions internal or 250 millivolts external at 200 mega
hertz.
AC Coupled: 0.3 division internal or 50 millivolts
external from 60 hertz to 40 megahertz, increasing to 1.5
divisions internal or 250 millivolts external at 200 mega
hertz. Attenuates all signals below about 60 hertz.
®
1-1
Summary of Contents for 475
Page 6: ...475 475 Oscilloscope ...
Page 20: ......
Page 46: ......
Page 151: ...A B C D E F G Fig 7 4 P 0 A4 Vertical Mode Switch circuit board ...
Page 152: ...n m m m 1 t siumm c ii im ...
Page 154: ...Diagrams 475 A B C D E F G ...
Page 155: ...GRID LOCATOR Fig 7 8 P O A3 Vertical Preamp circuit board ...
Page 157: ...Diagrams 475 ...
Page 158: ...GRID LOCATOR 2 3 4 5 6 7 8 9 1 10 11 1 12 Fig 7 10 P 0 A3 Vertical Preamp circuit board ...
Page 160: ...Diagrams 475 GRID LOCATOR Fig 7 11 A5 Vertical Output circuit board ...
Page 163: ...Diagrams 475 GRID LOCATOR Fig 7 12 P O A8 Trigger Generator And Sweep Logic circuit board ...
Page 167: ... 415 OSCILLOSCOPE B T R IG G E R G E N E R A T O R g B TR IG G E R GEN ER A TO R ...
Page 168: ...Diagrams 475 GRID LOCATOR ...
Page 172: ...SWEEP G E N ER A TO R S ...
Page 175: ...TIM IN G HORIZONTAL DISPLAY SWITCHING ...
Page 177: ...A 011 HORIZONTAL AMPLIFIER 8 l j k J Ll J Ol Z o N C O X U 1 C L O o v O o _J V v P O in r ...
Page 179: ... 476 OSCILLOSCOPE ...
Page 180: ...POWER SUPPLY ...
Page 182: ...CRT CIRCUIT ...
Page 185: ...C A L IB R A T O R A N D F A N C I R C U I T 4 C A LIB R A TO R FAN MOTOR C IR C U IT ...
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Page 190: ...4 T 475 OSCILLOSCOPE FIG 1 FRO NT PANEL ...
Page 191: ...475 OSCILLOSCOPE FIG 2 MAIN FRAME ...
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Page 200: ...FIG 3 RIGHT SIDE l 475 OSCILLOSCOPE ...
Page 201: ...V S X O t l B O T T OVJ 8 8 ...
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Page 210: ...5 ...
Page 211: ...4 4 75 O S C ILLO S C O P E FIG 5 CAB IN ET ...
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Page 241: ... 1 I R I II9A po S IT I o n f i n e I R l 130 PAGE 4 OF 5 R 1234 Ml 9 91 9 473 ...