BK Precision 2522C Instruction Manual

INSTRUCTION

MANUAL

Model 2522C

20 MHz DIGITAL STORAGE/ANALOG

OSCILLOSCOPE

TEST INSTRUMENT SAFETY

WARNING

Normal use of test equipment exposes you to a certain amount of danger from electrical shock because testing
must oft en b e pe rf orm ed w her e ex pos ed h igh vol ta ge i s pre se nt. An e lec tri cal sho ck c au sin g 10 milliamps of current
to pass through the heart will stop most human heartbeats. Voltage as 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 th reat because such voltage can more eas ily 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 significantl y 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 to protect 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-1 10 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

TABLE OF CONTENTS

TEST INSTRUMENT SAFETY..........................................................................................................2

TABLE OF CONTENTS....................................................................................................................3

FEATURES.......................................................................................................................................4

SPECIFICATIONS ............................................................................................................................6

CONTROLS AND INDICATORS ......................................................................................................8

GENERAL FUNCTION CONTROLS ............................................................................................................8

VERTICAL CONTROLS ...............................................................................................................................8

HORIZONTAL CONTROLS........................................................................................................................10

TRIGGERING CONTROLS........................................................................................................................10

DIGITAL STORAGE CONTROLS ..............................................................................................................12

REAR PANEL CONTROLS........................................................................................................................12

OPERATING INSTRUCTIONS .......................................................................................................13

SAFETY PRECAUTIONS...........................................................................................................................13

EQUIPMENT PROTECTION PR ECAUTIONS.........................................................................................13

OPERATING TIPS......................................................................................................................................14

INITIAL STARTING PROCEDURE.............................................................................................................14

SINGLE TRACE DISPLAY .........................................................................................................................14

DUAL TRACE DISPLAY.............................................................................................................................14

TRIGGERING.............................................................................................................................................15

MAGNIFIED SWEEP OPERATION............................................................................................................17

X Y OPERATION ......................................................................................................................................17

VIDEO SIGNAL OBSERVATION................................................................................................................17

DIGITAL STORAGE OPERATION .............................................................................................................17

MAINTENANCE..............................................................................................................................20

FUSE REPLACEMENT ..............................................................................................................................20

LINE VOLTAGE SELECTION.....................................................................................................................20

PERIODIC ADJUSTMENTS.......................................................................................................................20

CALIBRATION CHECK ..............................................................................................................................21

INSTRUMENT REPAIR SERVICE.............................................................................................................21

APPENDIX I....................................................................................................................................22

IMPORTANT CONSIDERATIONS FOR RISE TIME AND FALL TIME MEASUREMENTS.......................22

APPENDIX II...................................................................................................................................23

UNIQUE CHARACTERISTICS OF DIGITAL STORAGE OSCILLSCOPES...............................................23

ALIASING ...................................................................................................................................................23

EQUIVALENT TIME SAMPLING................................................................................................................23

SERVICE INFORMATION...............................................................................................................25

LIMITED ONE-YEAR WARRANTY ................................................................................................25

3

FEATURES

LOW COST, HIGH PERFORMANCE

B&K Precision’s Model 2522C 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 mode with
infinite resolution. Digital storage modes include 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.

DUAL TRACE FEATURES

Dual Trace

Model 2522C 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.

DIGITAL STORAGE FEATURES

High Resolution

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

High Sampling Rate

Sampling Rate up to 40 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.

CRT FEATURES

Rectangular CRT

Rectangular CRT with large 8 x 10 centimeter viewing
area.

Convenience

Trace rotation electrically adjustable from front panel. 0%,
10%, 90%, and 100% markers for rise time 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 sensitivity for full bandwidth. High-sensitivity
1 mV/div and 2 mV/div using PULL X5 gain control.

Calibrated Voltage Measurements

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 S/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.

4

FEATU RES

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 Trigger Sources

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

Video Sync

Frame (TV V) or Line (TV H) triggering selectable
for observing composite video waveforms. TV-H
position 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

XY 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 50 Ω 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 50 Ω .

Supplied With Two Probes

5

SPECIFICATIONS

CRT

Type: 6-inch rectangular with integral graticule, P31

phosphor.

Display Area: 8 x 10 div (1 div = 1 cm).
Accelerating Voltage: 2 kV.
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: 1 M2%.
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 atX5 MAG.

Overshoot: Less than 5%.

Operating Modes:

CH 1:

CH 2:

DUAL:

ADD:

Chop Frequency: Approximately 500 kHz.
Polarity Reversal: CH 2 invert.
Maximum Input Voltage: 400 V (dc + ac peak).

CH 1, single trace.

CH 2, single trace.

CH 1 and CH 2, dual trace.
Alternate or Chop selectable at
any sweep rate.

Algebraic sum of CH 1 + CH 2.

HORIZONTAL AMPLIFIER

(Input through channel 1 input)

XY mode:

CH 1 = X axis.
CH2 = Y axis.

Sensitivity: Same as vertical channel 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. Maximum
Input Voltage: 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 provides fully adjustable sweep
time between steps.

Accuracy: ±3%, except ±20% on 0.1 S/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.

6

Trigger Sensitivity:

AC: 1.0 div (internal)

≥0.5 Vp-p (external)
30 Hz – 20 MHz

TV-V: 1.0 div (internal)

≥0.5 Vp-p (external)
20 Hz – 20 kHz

TV-H: 1.0 div (internal)

≥0.5 Vp-p (external)
3 kHz – 100 kHz

Maximum External Trigger Voltage: 300 V (dc +

ac peak).

DIGITAL STORAGE FACILITIES

Storage Word Size:

8 bits/channel (2 k/channel with direct

2048 x
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 s/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/div and slower have selectable 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.

Equivalent Time Sampling Bandwidth:

20 MHz for repetitive waveforms.

USB Host Interface

Save screen image to USB flash drive

OTHER SPECIFICATIONS

Cal/Probe Compensation 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, 5 0/60 Hz,

55 watts.

Dimensions (H

(132

X 324 X 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.

3 W 3 D): 5.2” X 12.8” X 15.7”

ACCESSORIES SUPPLIED:

Two Switchable X1/X10 Probes.

Instruction Manual.

AC Line Cord.

Dot Joining:

Linear interpolation between samples.

Digital Display Modes:

Roll:

Stored data and display updated continually.

Refresh:

Stored data and display updated by triggered sweep.

Hold:

Freezes channel 1 and channel 2 data immediately.

Save CH2:

Freezes channel 2 data immediately.

Pretrigger Storage:

Available in single sweep mode, switchable to 0%,
25%, 50%, or 75%.

7

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CONTROLS AND INDICAT ORS

GENERAL FUNCTION CONTROLS

ON Indicator. Lights when oscilloscope is “on”.

1.
POWER Pushbutton. Turns oscilloscope “on” and

2.

“off”.

INTENSITY Control. Adjusts brightness of trace.

3.
TRACE ROTATION Control. Adjusts to maintain

4.

trace at a horizontal position.

5.

FOCUS Control. Adjusts trace focus. The inputs from channel 1 and channel 2 are
GND Terminal. Oscilloscope chassis ground

6.

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

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

7.

(nominal) square wave signal. This signal is useful for

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.

Fig. 1. Model 2522C Controls and Indicators.

X-Y:

used in conjunction with the

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

nel 1 POSition/PULL CHOP control.

ADD:

summed and displayed as a single signal. If the
Channel 2
pulled out, the input from channel 2 is subtracted

from channel 1 and the difference is displayed as a
single signal.

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

9.

switch with the followin

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.

POSition/PULL INVert control is

ositions:

X-Y

control and

-

8