BK Precision 2522B User Manual

INSTRUCTION

+

BK PRECISION

®

MANUAL

MODEL 2522B

20 MHz DIGITAL STORAGE/ANALOG

OSCILLOSCOPE

+

®

BK PRECISION

TEST INSTRUMENT SAFETY

WARNING

Normal use of test equipment exposes you to a certain amount of danger from electrical shock because
testing must often be performed where exposed high voltage is present. An electrical shock causing
10milliampsofcurrentto pass throughtheheart will stop most human heartbeats. Voltageas low as 35 volts
dc or ac rms should be considered dangerous and hazardous since it can produce a lethal current under
certain conditions. Higher voltage poses an even greater threat because such voltage can more easily
produce a lethal current. Your normal work habits should include all accepted practices that will prevent
contact with exposed high voltage, and that will steer current away from your heart in case of accidental
contact with a high voltage. You will significantly reduce the risk factor if you know and observe the
following safety precautions:

1. Don’t expose high voltage needlessly in the equipment under test. Remove housings and covers only when necessary.
Turn off equipment while making test connections in high-voltage circuits. Discharge high-voltage capacitors after
removing power.

2. If possible, familiarize yourself with the equipment being tested and the location of its high voltage points. However,
remember that high voltage may appear at unexpected points in defective equipment.

3. Use an insulated floor material or a large, insulated floor mat to stand on, and an insulated work surface on which to
place equipment; make certain such surfaces are not damp or wet.

4. Use the time-proven “one hand in the pocket” technique while handling an instrument probe. Be particularly careful to
avoid contacting a nearby metal object that could provide a good ground return path.

5. When using a probe, touch only the insulated portion. Never touch the exposed tip portion.

6. When testing ac powered equipment, remember that ac line voltage is usually present on some power input circuits such
as the on-off switch, fuses, power transformer, etc. any time the equipment is connected to an ac outlet, even if the
equipment is turned off.

7. Some equipment with a two-wire ac power cord, including some with polarized power plugs, is the “hot chassis” type.
This includes most recent television receivers and audio equipment. A plastic or wooden cabinet insulates the chassis
toprotect the customer. When the cabinet is removed for servicing, a serious shock hazard exists if the chassis is touched.
Not only does this present a dangerous shock hazard, but damage to test instruments or the equipment under test may
result from connecting the ground lead of most test instruments (including this oscilloscope) to a “hot chassis”. To make
measurements in “hot chassis” equipment, always connect an isolation transformer between the ac outlet and the
equipment under test. The B+K Precision Model TR-110 or 1604A Isolation Transformer, or Model 1653A or 1655A
AC Power Supply is suitable for most applications. To be on the safe side, treat all two wire ac powered equipment as
“hot chassis” unless you are sure it has an isolated chassis or an earth ground chassis.

8. Never work alone. Someone should be nearby to render aid if necessary. Training in CPR (cardio-pulmonary
resuscitation) first aid is highly recommended.

Instruction Manual

for

+

BK PRECISION

®

Model 2522B

20 MHz

Digital Storage/Analog

Oscilloscope

©2000 B+K Precision Corp.

This symbol on oscilloscope means “refer to instruction manual
for further precautionary information”. This symbol appears in the
manual where the corresponding information is given.

®

+

1031 Segovia Circle, Placentia, CA 92870

TABLE OF CONTENTS

Page Page

TEST INSTRUMENT SAFETY . . . . . . inside front cover

FEATURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

CONTROLS AND INDICATORS . . . . . . . . . . . . . . . . . . 7

General Function Controls . . . . . . . . . . . . . . . . . . . . . . 7

Vertical Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Horizontal Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Triggering Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Digital Storage Controls. . . . . . . . . . . . . . . . . . . . . . . 10

Rear Panel Controls . . . . . . . . . . . . . . . . . . . . . . . . . . 10

OPERATING INSTRUCTIONS. . . . . . . . . . . . . . . . . . . 11

Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Equipment Protection Precautions. . . . . . . . . . . . . . . 11

Operating Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Initial Starting Procedure . . . . . . . . . . . . . . . . . . . . . . 12

Single TraceDisplay . . . . . . . . . . . . . . . . . . . . . . . . . 12

Dual Trace Display. . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Triggering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Magnified Sweep Operation . . . . . . . . . . . . . . . . . . . 15

X−Y Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Video SignalObservation. . . . . . . . . . . . . . . . . . . . . . 15

OPERATING INSTRUCTIONS (Continued)

Digital Storage Operation . . . . . . . . . . . . . . . . . . . . . 15

Applications Guidebook . . . . . . . . . . . . . . . . . . . . . . 17

MAINTENANCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Fuse Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Line Voltage Selection. . . . . . . . . . . . . . . . . . . . . . . . 18

PeriodicAdjustments. . . . . . . . . . . . . . . . . . . . . . . . . 18

Calibration Check . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Instrument Repair Service. . . . . . . . . . . . . . . . . . . . . 19

APPENDIX I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Important Considerations for Rise Time and

Fall Time Measurements . . . . . . . . . . . . . . . . . . . . 20

APPENDIX II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Unique Characteristics of Digital Storage

Oscilloscopes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Aliasing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Equivalent Time Sampling . . . . . . . . . . . . . . . . . . . . 21

Service Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

“Guidebook To Oscilloscopes”

Availability . . . . . . . . . . . . . . . . . . . . . inside back cover

2

FEATURES

LOW COST ,HIGH PERFORMANCE

B+K Precision’s Model 2522B is one of the lowest cost
digital storage oscilloscopes in the industry, yet it includes
all the basic features needed by most technicians and engi­neers. Unlike other digital oscilloscopes, it has a full analog
modewithinfiniteresolution.Digitalstoragemodesinclude
refresh, roll, and single sweep. Equivalent time storage
techniques allow storage of repetitive waveforms up to
20 MHz. This oscilloscope is built by and backed by B+K
Precision, a company that has been selling reliable, durable,
value priced test instruments for over 50 years.

DIGITAL STORAGE FEATURES

High Resolution

2048 samples across the width of the screen (200
samplesperdivision)assures good resolution ofstored
waveforms. 1024 samples taken at sweep rates of
10 µs/div to 0.1 µs/div.

High Sampling Rate

Sampling Rate up to 10 Ms/s (Megasamples per sec­ond) for storing one-time events down to 50 nS.

Slow Event Display

X100 time base selections extend sweep time to 50
seconds/division. Excellent for displaying slow speed
events.

Equivalent Time Sampling

Allows repetitive waveforms up to 20 MHz to be
stored.

Pretrigger Capture

Permits viewing activity before the trigger occurs.
Selectable 0%, 25%, 50%, or 75% pre-trigger view.

Plotter Output

Analog output plus TTL Pen-Down control for strip
chart recorder or X-Y plotter.

CRT FEATURES

Rectangular CRT

Rectangular CRTwith large 8 x 10 centimeterviewing
area.

Convenience

Tracerotation electrically adjustable from front panel.
0%, 10%, 90%, and 100% markers for rise time meas­urements.

DUAL TRACEFEATURES

Dual Trace

Model 2522B has two vertical input channels for dis­playing two waveforms simultaneously. Selectable
single trace (either CH 1 or CH 2) or dual trace.
Alternate or chop sweep selectable at all sweep rates.

Sum and Difference Capability

Permits algebraic addition or subtraction of channel 1
and channel 2 waveforms, displayed as a single trace.
Useful for differential voltage and distortion measure­ments.

HIGH FREQUENCY FEATURES

Wide Bandwidth

Conservatively-rated −3 dB bandwidth is dc to 20
MHz.

Fast Rise Time

Rise time is less than 18 nS.

Fast Sweep

Maximum sweep speed of 10 nS/div (with X10 MAG)
assures high frequencies and short-duration pulses are
displayed with high resolution.

VERTICAL FEATURES

High Sensitivity

5 mV/div sensitivityfor full bandwidth. High-sen­sitivity 1 mV/div and 2 mV/div using PULL X5 gain
control.

Calibrated VoltageMeasurements

Accurate voltage measurements (±3%) on 10 cali­brated ranges from 5 mV/div to 5 V/ div. Vertical gain
fully adjustable between calibrated ranges.

SWEEP FEATURES

Calibrated Time Measurements

Accurate (±3%) time measurements. The main sweep
has 21 calibrated ranges from 0.5 s/div to 0.1 µS/div.
Sweep time is fully adjustable between calibrated
ranges.

X10 Sweep Magnification

Allows closer examination of waveforms, increases
maximum sweep rate to 10 nS/div.

3

FEATURES

TRIGGERING FEATURES

Two Trigger Modes

Selectable normal (triggered) or automatic sweep
modes.

Triggered Sweep

Sweep remains at rest unless adequate trigger signal is
applied. Fully adjustable trigger level and (+) or (−)
slope.

AUTO Sweep

Selectable AUTO sweep provides sweep without trig­ger input, automatically reverts to triggered sweep
operation when adequate trigger is applied.

Five TriggerSources

Five trigger source selections, including CH 1, CH 2,
alternate, EXT, and LINE.

Video Sync

Frame(TV V) or Line (TV H) triggering selectablefor
observingcomposite video waveforms.TV-Hposition
can also be used as low frequency reject and TV-V
position can be used as high frequency reject.

Variable Holdoff

Trigger inhibit period after end of sweep adjustable.
Permits stable observation of complex pulse trains.

OTHER FEATURES

X−Y Operation

Channel 1 can be applied as horizontal deflection
(X-axis) while channel 2 provides vertical deflection
(Y-axis).

Built-in Probe Adjust Square Wave

A 0.5 V p-p, 1 kHz square wave generator permits
probe compensation adjustment.

Channel 2 (Y) Output

A buffered 50Ω output of the channel 2 signal is
available at the rear panel for driving a frequency
counter or other instruments. The output is 50 mV/div
(nominal) into 50Ω.

Supplied With TwoProbes

4

SPECIFICATIONS

CRT

Type: 6-inch rectangular with integral graticule, P31

phosphor.

DisplayArea:8 x 10 div (1 div = 1 cm).
AcceleratingVoltage:2kV.
Phosphor:P31.
Trace Rotation: Electrical, front panel adjustable.

VERTICAL AMPLIFIERS (CH 1 and CH 2)

Sensitivity: 5 mV/div to 5 V/div, 1 mv/div to 1 V/div at

X5 MAG.

Attenuator:10 calibrated steps in 1-2-5 sequence.Vernier

control provides fully adjustable sensitivity between
steps; range 1/1 to at least 1/3.

Accuracy:±3%, 5 mV to 5 V/div; 5%, at X5 MAG.
Input Resistance:1MΩ±2%.
Input Capacitance: 25 pF ±10 pF.
Frequency Response:

5 mV/div to 5 V/div:

DC to 20 MHz (−3 dB).

X5 MAG:

DC to 10 MHz (−3 dB).

Rise Time:

18 nS; 35 nS at X5 MAG.

Overshoot:Less than 5%.
Operating Modes:

CH 1: CH 1, single trace.
CH 2: CH 2, single trace.
DUAL: CH 1 and CH 2, dual trace.

Alternate or Chop selectable at
any sweep rate.

ADD: Algebraic sum of CH 1 + CH 2.

Chop Frequency:Approximately 500 kHz.
PolarityReversal:CH 2 invert.
MaximumInput Voltage:400 V (dc + ac peak).

HORIZONTAL AMPLIFIER

(Input through channel 1 input)

X−Y mode:

CH 1 = X axis.
CH 2 = Y axis.

Sensitivity: Same as verticalchannel 2.
Input Impedance: Same as vertical channel 2.
Frequency Response:

DC to 1 MHz (−3 dB).

X-Y Phase Difference: 3° or less at 50 kHz.
MaximumInputVoltage: Same as vertical channel 1.

SWEEP SYSTEM

Time Base: 0.1 µS/div to 0.5 S/div in 1-2-5 sequence,

21 steps. Vernier control providesfully adjustable
sweep time between steps.

Accuracy:±3%, except ±20% on 0.1 µS/div.
Sweep Magnification: X10 ±10%.
Holdoff: Continuously adjustable for main time base from

NORM to 5 times normal.

TRIGGERING

Trigger Modes:

AUTO (free run), NORM, TV-V, TV-H.

Trigger Source:

CH 1, CH 2, Alternate, EXT,LINE.

Slope:

(+) or (–).

Trigger Coupling:

AUTO: Sweep free-runs in absence of

suitable trigger signal.

NORM: Sweep triggered only by adequate

trigger signal.

TV-V: Video vertical sync pulses are

selected. Also usable for high
frequency reject.

TV-H: Video horizontal sync pulses are

selected. Also usable for low
frequency reject.

5

SPECIFICATIONS

Trigger Sensitivity:

AC: 1.0 div (internal)

≥0.5 Vp-p (external)

30 Hz – 30 MHz

TV-V: 1.0 div (internal)

≥0.5 Vp-p (external)

20 Hz – 30 kHz

TV-H: 1.0 div (internal)

≥0.5 Vp-p (external)
3 kHz – 100 kHz

MaximumExternalTriggerVoltage: 300 V (dc + ac

peak).

DIGITAL STORAGE FACILITIES

Storage Word Size:

2048 3 8 bits/channel (2 k/channel with direct sam­pling, 1 k/channel with equivalent time sampling).

Vertical Resolution:

8 bit (1 in 256) approximately 25 steps/div.

Horizontal Resolution:

1 in 2048, approximately 200 samples/div.

Sampling Rate:

10 M samples/sec to 4 samples/sec, reduced in propor­tion to time base. Direct sampling at time base settings
of 20 µs/div and slower, equivalent time sampling at
time base settings of 10 µs/div and faster.

Time Base Expander:

For storage of slow time events, time base steps
10 ms/divandslowerhaveselectable 1/1 or 1/100 rate.
1/100 rate expands time base from 1 sec/div to 50
sec/div in 1-2-5 sequence.

Equivqlent Time Sampling Bandwidth:

20 MHz for repetitive waveforms.

Dot Joining:

Linear interpolation between samples.

Digital Display Modes:

Roll:

Stored data and display updated continually.

Refresh:

Storeddataanddisplay updated by triggeredsweep.

Hold:

Freezes channel 1 and channel 2 data immediately.

Save CH 2:

Freezes channel 2 data immediately.

Pretrigger Storage:

Available in single sweepmode, switchable to 0%,

25%, 50%, or 75%.

PLOT OUTPUT

Analog output of the stored display.

CH 1 and CH 2 Outputs:

Selected by PLOT switch. Output via CH1 OUTPUT
and CH2 OUTPUT jacks on rear panel. Amplitude

0.2 V/div (2 V maximum).

Output Sweep Rate:

Output sweep rate is 1/10 of TIME/DIV setting (and
1/100 switch when applicable).

Pen Lift Output:

Availableat PEN DOWNjack on rearpanel,TTL high,
pen up. TTL low, pen down.

OTHER SPECIFICATIONS

Cal/ProbeCompensation Voltage:0.5 V p-p ±3% square

wave,1 kHz nominal.

CH 2 (Y) Output:

Output Voltage: 50 mV/div (nominal into 50 ohm

load).

Output Impedance: Approximately 50 ohms.
Frequency Response:20 Hz to 20 MHz, −3 dB.

Power Requirements: 100–130 VAC or 200–260 VAC,

50/60 Hz, 55 watts.

Dimensions (H 3 W3 D):

5.2″ 3 12.8″ 3 15.7″
(132 3 324 3 398 mm).

Weight: 18.7 lbs (8.5 kg).
Environment:

Within Specified Accuracy: +10° to +35° C, 10–80%

relative humidity.

Full Operation: 0° to +50° C, 10–80% relative

humidity.

Storage: −30° to +70° C, 10–90% relative humidity.

ACCESSORIES SUPPLIED:

Two Switchable X1/X10 Probes.

Instruction Manual.
AC Line Cord.

6

CONTROLS AND INDICATORS

14

13

5

3

1

4

2

26

25

24

23

22 21

20

19

37

38

30

29

31

32

36

33

34

35

9

Fig. 1. Model 2522B Controls and Indicators.

GENERAL FUNCTION CONTROLS

1. ON Indicator. Lights when oscilloscope is “on”.

2. POWER Pushbutton. Turns oscilloscope “on” and

“off”.

3. INTENSITY Control. Adjusts brightness of trace.

4. TRACE ROTATION Control. Adjusts to maintain

trace at a horizontal position.

5. FOCUS Control. Adjusts trace focus.

6. GND Terminal. Oscilloscope chassis ground

jack, and earth ground via three-wire ac power cord.

7. CAL Terminal. Terminal provides 0.5 V p-p, 1 kHz

(nominal) square wave signal. This signal is useful for
checking probe compensation adjustment, as well as
providing a rough check of vertical calibration.

VERTICAL CONTROLS

8. VERTical MODE Switch. Selects vertical display

mode. Four-position lever switch with the following
positions:

CH1:

Displays the channel 1 signal by itself.

CH2/X-Y:

CH2: displays the channel 2 signal by itself.

10

11

12

6

28

7

8

15

16

17

2718

X-Y: used in conjunction with the X-Y control and
Trigger SOURCE switch to enable X-Y display

mode.

DUAL:

Displays the channel 1 and channel 2 signals simul­taneously. Dual-trace mode may be either alternate
orchoppedsweep;see the description underCHan-

nel 1 POSition/PULL CHOP control.

ADD:

The inputs from channel 1 and channel 2 are
summed and displayed as a single signal. If the
Channel 2 POSition/PULL INVert control is
pulled out, the input from channel 2 is subtracted
from channel 1 and the difference is displayed as a
single signal.

9. CH1 AC-GND-DC Switch. Three-position lever

switch with the following positions:

AC:

Channel 1 input signal is capacitively coupled; dc
component is blocked.

GND:

Opens signal path and grounds input to vertical
amplifier. This provides a zero-volt base line, the
position of which can be used as a reference when
performing dc measurements.

7