BK Precision 5105A Instruction Manual
150 MHz (200MS/s) ANALOG/DIGITAL OSCILLOSCOPE
+
INSTRUCTION
MANUAL
MODELS 5105A
¨
3
Subject to change without notice
Table of contents
Oscilloscope
5105A
St.250900-Hüb/tke
Specifications ................................................................... 5
General Information ........................................................ 4
Symbols ........................................................................ 4
Use of tilt handle .......................................................... 4
Safety ............................................................................ 4
Type of signal voltage ..................................................... 6
Amplitude Measurements ............................................ 6
Total value of input voltage .......................................... 7
Time Measurements .................................................... 7
Connection of Test Signal............................................. 8
Controls and Readout...................................................... 9
First Time Operation ...................................................... 25
Trace Rotation TR ....................................................... 25
Probe compensation and use .................................... 2 5
Adjustment at 1kHz .................................................... 26
Adjustment at 1MHz .................................................. 26
Operating modes of the vertical
amplifiers in Yt mode ................................................. 26
X-Y Operation .............................................................. 27
Phase comparison with Lissajous figures ................. 27
Phase difference measurement
in DUAL mode (Yt) ...................................................... 27
Phase difference measurement in DUAL mode ....... 28
Measurement of an amplitude modulation ............... 28
Triggering and time base .............................................. 28
Automatic Peak (value) -Triggering ............................ 29
Normal Triggering ....................................................... 29
- Slope.................................................................... 29
Trigger coupling........................................................... 29
Triggering of video signals .......................................... 30
Line / Mains triggering (~).......................................... 3 0
Alternate triggering ..................................................... 30
External triggering ...................................................... 31
HOLD OFF-time adjustment ...................................... 31
B time base (2nd time base) /.................................... 31
Triggering after Delay ................................................. 31
AUTO SET ....................................................................... 3 2
Component Tester (analog mode)............................... 32
General........................................................................ 32
Using the Component Tester ..................................... 33
Test Procedure ............................................................ 3 3
Test Pattern Displays .................................................. 33
Testing Resistors ........................................................ 33
Testing Capacitors and Inductors ............................... 33
Testing Semiconductors ............................................. 3 3
Testing Diodes ............................................................ 33
Testing Transistors ...................................................... 34
In-Circuit Tests ............................................................ 34
Storage mode ................................................................. 3 4
Signal recording modes.............................................. 3 5
Vertical resolution ....................................................... 3 5
Horizontal resolution................................................... 35
Maximum signal frequency in storage mode ............ 35
Alias signal display ...................................................... 36
Test Instructions ............................................................. 36
General........................................................................ 36
Cathode Ray Tube:
Brightness and Focus,
Linearity, Raster Distortion ......................................... 3 6
Astigmatism Check .................................................... 36
Symmetry and Drift of the Vertical Amplifier ............ 36
Calibration of the Vertical Amplifier ............................ 36
Transmission Perfor mance ......................................... 37
of the Vertical Amplifier.............................................. 37
Operating Modes: CH.I/II, DUAL, ADD,
CHOP., INVERT and X-Y Operation............................ 3 7
Triggering Checks ....................................................... 37
Time base .................................................................... 38
Hold Off time .............................................................. 38
Component Tester ...................................................... 38
Trace Alignment .......................................................... 3 8
Adjustments................................................................ 38
RS232 Interface - Remote Control ............................... 3 8
Safety .......................................................................... 38
Operation .................................................................... 38
Baud-Rate Setting ....................................................... 3 8
Data Communication .................................................. 38
Front control 5105A ....................................................... 39
Subject to change without notice
4
KONFORMITÄTSERKLÄRUNG
DECLARATION OF CONFORMITY
DECLARATION DE CONFORMITE
®
Instruments
Herstellers HAMEG GmbH
Manufacturer Kelsterbacherstraße 15-19
Fabricant D - 60528 Frankfurt
Bezeichnung / Product name / Designation:
Oszilloskop/Oscilloscope/Oscilloscope
Typ / Type / Type: HM1507-3
mit / with / avec: -
Optionen / Options / Options: HO79-6
mit den folgenden Bestimmungen / with applicable regulations / avec les
directives suivantes
EMV Richtlinie 89/336/EWG ergänzt durch 91/263/EWG, 92/31/EWG
EMC Directive 89/336/EEC amended by 91/263/EWG, 92/31/EEC
Directive EMC 89/336/CEE amendée par 91/263/EWG, 92/31/CEE
Niederspannungsrichtlinie 73/23/EWG ergänzt durch 93/68/EWG
Low-Voltage Equipment Directive 73/23/EEC amended by 93/68/EEC
Directive des equipements basse tension 73/23/CEE amendée par 93/68/CEE
Angewendete harmonisierte Normen / Harmonized standards applied / Normes
harmonisées utilisées
Sicherheit / Safety / Sécurité
EN 61010-1: 1993 / IEC (CEI) 1010-1: 1990 A 1: 1992 / VDE 0411: 1994
EN 61010-1/A2: 1995 / IEC 1010-1/A2: 1995 / VDE 0411 Teil 1/A1: 1996-05
Überspannungskategorie / Overvoltage category / Catégorie de surtension: II
Verschmutzungsgrad / Degree of pollution / Degré de pollution: 2
Elektromagnetische Verträglichkeit / Electromagnetic compatibility
Compatibilité électromagnétique
EN 50082-2: 1995 / VDE 0839 T82-2
ENV 50140: 1993 / IEC (CEI) 1004-4-3: 1995 / VDE 0847 T3
ENV 50141: 1993 / IEC (CEI) 1000-4-6 / VDE 0843 / 6
EN 61000-4-2: 1995 / IEC (CEI) 1000-4-2: 1995 / VDE 0847 T4-2
Prüfschärfe / Level / Niveau = 2
EN 61000-4-4: 1995 / IEC (CEI) 1000-4-4: 1995 / VDE 0847 T4-4:
Prüfschärfe / Level / Niveau = 3
EN 50081-1: 1992 / EN 55011: 1991 / CISPR11: 1991 / VDE0875 T11: 1992
Gruppe / group / groupe = 1, Klasse / Class / Classe = B
Datum /Date /Date Unterschrift / Signature /Signatur
23.04.1999
G. Hübenett
QMB
General information regarding the CE marking
B&K instruments fulfill the regulations of the EMC directive. The conformity test made by B&K is based on the actual
generic and product standards. In cases where different limit values are applicable, B&K applies the severer standard. For
emission the limits for residential, commercial and light industry are applied. Regarding the immunity (susceptibility) the limits
for industrial environment have been used.
The measuring- and data lines of the instrument have much influence on emmission and immunity and therefore on meeting the
acceptance limits. For different applications the lines and/or cables used may be different. For measurement operation the
following hints and conditions regarding emission and immunity should be observed:
1. Data cables
For the connection between instruments resp. their interfaces and external devices, (computer, printer etc.) sufficiently shielded
cables must be used. Without a special instruction in the manual for a reduced cable length, the maximum cable length of a
dataline must be less than 3 meters long. If an interface has several connectors only one connector must have a connection to
a cable.
Basically interconnections must have a double shielding.
2. Signal cables
Basically test leads for signal interconnection between test point and instrument should be as short as possible. Without
instruction in the manual for a shorter length, signal lines must be less than 3 meters long. Signal lines must shielded (coaxial
cable - RG58/U). A proper ground connection is required. In combination with signal generators double shielded cables (RG223/
U, RG214/U) must be used.
3. Influence on measuring instruments.
Under the presence of strong high frequency electric or magnetic fields, even with careful setup of the measuring equipment an
influence of such signals is unavoidable.
This will not cause damage or put the instrument out of operation. Small deviations of the measuring value (reading) exceeding
the instruments specifications may result from such conditions in individual cases.
4. RF immunity of oscilloscopes.
4.1 Electromagnetic RF field
The influence of electric and magnetic RF fields may become visible (e.g. RF superimposed), if the field intensity is high. In most
cases the coupling into the oscilloscope takes place via the device under test, mains/line supply, test leads, control cables and/
or radiation. The device under test as well as the oscilloscope may be effected by such fields.
Although the interior of the oscilloscope is shielded by the cabinet, direct radiation can occur via the CRT gap. As the bandwidth
of each amplifier stage is higher than the total –3dB bandwidth of the oscilloscope, the influence RF fields of even higher
frequencies may be noticeable.
4.2 Electrical fast transients / electrostatic discharge
Electrical fast transient signals (burst) may be coupled into the oscilloscope directly via the mains/line supply, or indirectly via
test leads and/or control cables. Due to the high trigger and input sensitivity of the oscilloscopes, such normally high signals
may effect the trigger unit and/or may become visible on the CRT, which is unavoidable. These effects can also be caused by
direct or indirect electrostatic discharge.
Subject to change without notice
6
General Information
This oscilloscope is easy to operate. The logical arrangement
of the controls allows anyone to quickly become familiar with
the operation of the instrument, however, experienced users
are also advised to read through these instructions so that all
functions are understood.
Immediately after unpacking, the instrument should be
checked for mechanical damage and loose parts in the interior .
If there is transport damage, the supplier must be informed
immediately. The instrument must then not be put into
operation.
Symbols
ATTENTION - refer to manual
Danger - High voltage
Protective ground (earth) terminal
Use of tilt handle
To view the screen from the best angle, there are three
different positions (C, D, E) for setting up the instrument. If
the instrument is set down on the floor after being carried,
the handle automatically remains in the upright carrying
position (A). In order to place the instrument onto a horizontal
surface, the handle should be turned to the upper side of the
oscilloscope (C). For the D position (10° inclination), the handle
should be turned to the opposite direction of the carrying
position until it locks in place automatically underneath the
instrument. For the E position (20° inclination), the handle
should be pulled to release it from the D position and swing
backwards until it locks once more. The handle may also be
set to a position for horizontal carrying by turning it to the
upper side to lock in the B position. At the same time, the
instrument must be lifted, because otherwise the handle will
snap back to the previous position.
Safety
This instrument has been designed and tested in accordance
with IEC Publication 1010-1 (overvoltage category II, pollution
degree 2), Safety requirements for electrical equipment for
measurement, control, and laboratory use. The CENELEC
regulations EN 61010-1 correspond to this standard. It has
left the factory in a safe condition. This instruction manual
contains important information and warnings which have to
be followed by the user to ensure safe operation and to retain
the oscilloscope in a safe condition.
The case, chassis and all measuring terminals are
connected to the protective earth contact of the
appliance inlet. The instrument operates according
to Safety Class I (three-conductor power cord with
protective earthing conductor and a plug with
earthing contact).
The main line plug shall only be inserted in a socket outlet
provided with a protective earth contact. The protective action
must not be negated by the use of an extension cord without
a protective conductor.
The main line plug must be inserted before connections are made to measuring circuits.
The grounded accessible metal parts (case, sockets, jacks)
and the main line supply contacts (line/live, neutral) of the
instrument have been tested against insulation breakdown
with 2200V DC.
Under certain conditions, 50Hz or 60Hz hum voltages can
occur in the measuring circuit due to the interconnection with
other main line powered equipment or instruments. This
can be avoided by using an isolation transformer (Safety Class
II) between the main line outlet and the power plug of the
device being investigated.
Most cathode-ray tubes develop X-rays.
However, the dose equivalent rate falls far below the
maximum permissible value of 36pA/kg (0.5mR/h).
Whenever it is likely that protection has been impaired, the
instrument shall be made inoperative and be secured against
any unintended operation. The protection is likely to be
impaired if, for example, the instrument
• shows visible damage,
• fails to perform the intended measurements,
• has been subjected to prolonged storage under unfavorable
conditions (e.g. in the open or in moist environments),
• has been subject to severe transport stress (e.g. do to
packaging).
Intended purpose and operating conditions
This instrument must be used only by qualified experts who
are aware of the risks of electrical measurement.
The instrument is specified for operation in industry, light
industry, commercial and residential environments.
Due to safety reasons the instrument must only be connected
to a properly installed power outlet, containing a protective
earth conductor. The protective earth connection must not
be broken. The power plug must be inserted in the power
outlet while any connection is made to the test device.
The instrument has been designed for indoor use. The
permissible ambient temperature range during operation is
+10°C (+50°F) ... +40°C (+104°F). It may occasionally be
subjected to temperatures between +10°C (+50°F) and -10°C
(+14°F) without degrading its safety. The permissible ambient
temperature range for storage or transportation is -40°C (0°F) ... +70°C (+158°F). The maximum operating altitude is
up to 2200m (non-operating 15000m). The maximum relative
humidity is up to 80%.
If condensed water exists in the instrument it should be
acclimatized before switching on. In some cases (e.g.
extremely cold oscilloscope) two hours should be allowed
before the instrument is put into operation. The instrument
General Information
7
Subject to change without notice
Protective Switch-Off
This instrument is equipped with a switch mode power supply.
It has both overvoltage and overload protection, which will
cause the switch mode supply to limit power consumption
to a minimum. In this case a ticking noise may be heard.
Power supply
The oscilloscope operates on main line voltages between
100VAC and 240VAC. No means of switching to different
input voltages has therefore been provided.
The power input fuses are externally accessible. The fuse
holder is located above the 3-pole power connector. The
power input fuses are externally accessible, if the rubber
connector is removed. The fuse holder can be released by
pressing its plastic retainers with the aid of a small screwdriver. The retainers are located on the right and left side of
the holder and must be pressed towards the center. The
fuse(s) can then be replaced and pressed in until locked on
both sides.
Use of patched fuses or short-circuiting of the fuse holder is
not permissible; B&K assumes no liability whatsoever for
any damage caused as a result, and all warranty claims
become null and void.
Fuse type:
Size 5x20mm; 0.8A, 250V AC fuse;
must meet IEC specification 127,
Sheet III (or DIN 41 662
or DIN 41 571, sheet 3).
Time characteristic: time-lag (T).
Attention!
There is a fuse located inside the instrument within
the switch mode power supply:
Size 5x20mm; 0.8A, 250V AC fuse;
must meet IEC specification 127,
Sheet III (or DIN 41 662
or DIN 41 571, sheet 3).
Time characteristic: fast (F).
This fuse must not be replaced by the operator!
should be kept in a clean and dry room and must not be
operated in explosive, corrosive, dusty, or moist environments. The oscilloscope can be operated in any position, but
the convection cooling must not be impaired. The ventilation
holes may not be covered. For continuous operation the
instrument should be used in the horizontal position,
preferably tilted upwards, resting on the tilt handle.
The specifications stating tolerances are only valid if the
instrument has warmed up for 30minutes at an ambient
temperature between +15°C (+59°F) and +30°C (+86°F).
Values without tolerances are typical for an average instrument.
EMC
This instrument conforms to the European standards regarding the electromagnetic compatibility. The applied standards
are: Generic immunity standard EN50082-2:1995 (for industrial environment) Generic emission standard EN50081-1:1992
(for residential, commercial and light industry environment).
This means that the instrument has been tested to the highest
standards.
Please note that under the influence of strong electromagnetic fields, such signals may be superimposed on the
measured signals.
Under certain conditions this is unavoidable due to the
instrument’s high input sensitivity, high input impedance and
bandwidth. Shielded measuring cables, shielding and earthing
of the device under test may reduce or eliminate those
effects.
General Information
Subject to change without notice
8
Type of signal voltage
The following description of the 5105A relates to the
analog-oscilloscope mode. Please note “Storage Operation”.
The oscilloscope 5105A allows examination of DC voltages and most repetitive signals in the frequency range up
to at least 150MHz (-3dB).
The vertical amplifiers have been designed for minimum
overshoot and therefore permit a true signal display.
The display of sinusoidal signals within the bandwidth limits
causes no problems, but an increasing error in measurement
due to gain reduction must be taken into account when
measuring high frequency signals. This error becomes
noticeable at approx. 70MHz. At approx. 110MHz the redu-
ction is approx. 10% and the real voltage value is 11% higher.
The gain reduction error can not be defined exactly as the -
3dB bandwidth of the amplifiers differ between 150MHz
and 170MHz.
For sine wave signals the -6dB limit is approx. 220MHz.
When examining square or pulse type waveforms, attention
must be paid to the harmonic content of such signals. The
repetition frequency (fundamental frequency) of the signal
must therefore be significantly smaller than the upper limit
frequency of the vertical amplifier.
Displaying composite signals can be difficult, especially if they
contain no repetitive higher amplitude content which can be
used for triggering. This is the case with bursts, for instance.
To obtain a well-triggered display in this case, the assistance
of the variable hold off function or the second time base may
be required. Television video signals are relatively easy to
trigger using the built-in TV-Sync-Separator (TV).
For optional operation as a DC or AC voltage amplifier, each
vertical amplifier input is provided with a DC/AC switch. DC
coupling should only be used with a series-connected attenuator probe or at very low frequencies or if the measurement of the DC voltage content of the signal is absolutely
necessary.
When displaying very low frequency pulses, the flat tops may
be sloping with AC coupling of the vertical amplifier (AC limit
frequency approx. 1.6 Hz for 3dB). In this case, DC operation
is preferred, provided the signal voltage is not superimposed
on a too high DC level. Otherwise a capacitor of adequate
capacitance must be connected to the input of the vertical
amplifier with DC coupling. This capacitor must have a
sufficiently high breakdown voltage rating. DC coupling is
also recommended for the display of logic and pulse signals,
especially if the pulse duty factor changes constantly.
Otherwise the display will move upwards or downwards at
each change. Pure direct voltages can only be measured with
DC coupling.
The input coupling is selectable by the AC/DC pushbutton.
The actual setting is displayed in the readout with the “ = “
symbol for DC- and the “ ~ “ symbol for AC coupling.
Amplitude Measurements
In general electrical engineering, alternating voltage data
normally refers to effective values (rms = root-mean-square
value). However, for signal magnitudes and voltage designations in oscilloscope measurements, the peak-to-peak
voltage (V
pp
) value is applied. The latter corresponds to the
real potential difference between the most positive and most
negative points of a signal waveform. If a sinusoidal
waveform, displayed on the oscilloscope screen, is to be
converted into an effective (rms) value, the resulting peakto-peak value must be divided by 2x√2 = 2.83. Conversely, it
should be observed that sinusoidal voltages indicated in V
rms
(V
eff
) have 2.83 times the potential difference in Vpp.
The relationship between the different voltage magnitudes
can be seen from the following figure.
Voltage values of a sine curve
V
rms
= effective value; Vp = simple peak or crest value;
V
pp
= peak-to-peak value; V
mom
= momentary value.
The minimum signal voltage which must be applied to the Y
input for a trace of 1div height is 1mV
pp
(± 5%) when this
deflection coefficient is displayed on the screen (readout)
and the vernier is switched off (VAR-LED dark). However,
smaller signals than this may also be displayed. The deflection
coefficients are indicated in mV/div or V/div (peak-to-peak
value).
The magnitude of the applied voltage is ascertained by
multiplying the selected deflection coefficient by the vertical
display height in div. If an attenuator probe x10 is used, a
further multiplication by a factor of 10 is required to ascertain
the correct voltage value.
For exact amplitude measurements, the variable control (VAR)
must be set to its calibrated detent CAL position.
With the variable control activated the deflection sensitivity
can be reduced up to a ratio of 2.5 to 1 (please note “controls
and readout”). Therefore any intermediate value is possible
within the 1-2-5 sequence of the attenuator(s).
With direct connection to the vertical input, signals
up to 400Vpp may be displayed (attenuator set to
20V/div, variable control to 2.5:1).
With the designations
H = display height in div,
U = signal voltage in V
pp
at the vertical input,
D = deflection coefficient in V/div at attenuator switch,
the required value can be calculated from the two given
quantities:
However, these three values are not freely selectable.
They have to be within the following limits (trigger threshold,
accuracy of reading):
H between 0.5 and 8div, if possible 3.2 to 8div,
U between 0.5mV
pp
and 160Vpp,
D between 1mV/div and 20V/div in 1-2-5 sequence.
Type of signal voltage
9
Subject to change without notice
Examples:
Set deflection coefficient D = 50mV/div 0.05V/div,
observed display height H = 4.6div,
required voltage U = 0.05x4.6 = 0.23V
pp
.
Input voltage U = 5V
pp
,
set deflection coefficient D = 1V/div,
required display height H = 5:1 = 5div.
Signal voltage U = 230Vrmsx 2
?√
2 = 651V
pp
(voltage > 160Vpp, with probe 10:1: U = 65.1Vpp),
desired display height H = min. 3.2div, max. 8div,
max. deflection coefficient D = 65.1:3.2 = 20.3V/div,
min. deflection coefficient D = 65.1:8 = 8.1V/div,
adjusted deflection coefficient D = 10V/div.
The previous examples are related to the CRT graticule
reading. The results can also be determined with the aid of
the ∆V cursor measurement (please note “controls and
readout”).
The input voltage must not exceed 400V , independent
from the polarity.
If an AC voltage which is superimposed on a DC voltage is
applied, the maximum peak value of both voltages must not
exceed + or -400V. So for AC voltages with a mean value of
zero volt the maximum peak to peak value is 800V
pp
.
If attenuator probes with higher limits are used, the
probes limits are valid only if the oscilloscope is set
to DC input coupling.
If DC voltages are applied under AC input coupling conditions
the oscilloscope maximum input voltage value remains 400V .
The attenuator consists of a resistor in the probe and the
1MΩ input resistor of the oscilloscope, which are disabled
by the AC input coupling capacity when AC coupling is
selected. This also applies to DC voltages with superimposed
AC voltages. It also must be noted that due to the capacitive
resistance of the AC input coupling capacitor, the attenuation
ratio depends on the signal frequency. For sine wave signals
with frequencies higher than 40Hz this influence is negligible.
With the above listed exceptions B&K 10:1 probes can
be used for DC measurements up to 600V or AC voltages
(with a mean value of zero volt) of 1200V
pp
. The 100:1 probe
HZ53 allows for 1200V DC or 2400Vpp for AC.
It should be noted that its AC peak value is derated at higher
frequencies. If a normal x10 probe is used to measure high
voltages there is the risk that the compensation trimmer
bridging the attenuator series resistor will break down causing
damage to the input of the oscilloscope. However, if for
example only the residual ripple of a high voltage is to be
displayed on the oscilloscope, a normal x10 probe is sufficient.
In this case, an appropriate high voltage capacitor (approx.
22-68nF) must be connected in series with the input tip of
the probe.
With Y-POS. control (input coupling to GD) it is possible to
use a horizontal graticule line as reference line for ground
potential before the measurement. It can lie below or above
the horizontal central line according to whether positive and/
or negative deviations from the ground potential are to be
measured.
Total value of input voltage
The dotted line shows a voltage alternating at zero volt level. If
superimposed on a DC voltage, the addition of the positive peak
and the DC voltage results in the max. voltage (DC + ACpeak).
Time Measurements
As a rule, most signals to be displayed are periodically repeating processes, also called periods. The number of periods
per second is the repetition frequency. Depending on the
time base setting (TIME/DIV.-knob) indicated by the readout,
one or several signal periods or only a part of a period can be
displayed. The time coefficients are stated in ms/div, µs/
div or ns/div. The following examples are related to the CRT
graticule reading. The results can also be determined with
the aid of the ∆t and 1/∆t cursor measurement (please note
“ controls and readout”).
The duration of a signal period or a part of it is determined by
multiplying the relevant time (horizontal distance in div) by
the (calibrated) time coefficient displayed in the readout .
Uncalibrated, the time base speed can be reduced until a
maximum factor of 2.5 is reached. Therefore any intermediate
value is possible within the 1-2-5 sequence.
With the designations
L = displayed wave length in div of one period,
T = time in seconds for one period,
F = recurrence frequency in Hz of the signal,
Tc = time coefficient in ms, µs or ns/div and the relation
F = 1/T, the following equations can be stated:
However, these four values are not freely selectable. They
have to be within the following limits:
L between 0.2 and 10div, if possible 4 to 10div,
T between 5ns and 5s,
F between 0.5Hz and 100MHz,
Tc between 50ns/div and 500ms/div in 1-2-5 sequence
(with X-MAG. (x10) inactive), and
Tc between 5ns/div and 50ms/div in 1-2-5 sequence
(with X-MAG. (x10) active).
Examples:
Displayed wavelength L = 7div,
set time coefficient Tc = 100ns/div,
required period T = 7x100x10
-9
= 0.7µs
required rec. freq. F = 1:(0.7x10-6) = 1.428MHz.
Signal period T = 1s,
set time coefficient Tc = 0.2s/div,
required wavelength L = 1:0.2 = 5div.
Displayed ripple wavelength L = 1div,
set time coefficient Tc = 10ms/div,
required ripple freq. F = 1:(1x10x10
-3
) = 100Hz.
TV-line frequency F = 15625Hz,
Type of signal voltage
Subject to change without notice
10
set time coefficient Tc = 10µs/div,
required wavelength L = 1:(15625x10
-5
) = 6.4div.
Sine wavelength L = min. 4div, max. 10div,
Frequency F = 1kHz,
max. time coefficient Tc = 1:(4x10
3
) = 0.25ms/div,
min. time coefficient Tc = 1:(10x10
3
) = 0.1ms/div,
set time coefficient Tc = 0.2ms/div,
required wavelength L = 1:(10
3
x0.2x10-3) = 5div.
Displayed wavelength L = 0.8div,
set time coefficient Tc = 0.5µs/div,
pressed X-MAG. (x10) pushbutton: Tc = 0.05µs/div,
required rec. freq. F = 1:(0.8x0.05x10
-6
) = 25MHz,
required period T = 1:(25x106) = 40ns.
If the time is relatively short as compared with the complete
signal period, an expanded time scale should always be
applied (X-MAG. (x10) active). In this case, the time interval
of interest can be shifted to the screen center using the XPOS. control.
When investigating pulse or square waveforms, the critical
feature is the rise time of the voltage step. To ensure that
transients, ramp-offs, and bandwidth limits do not unduly
influence the measuring accuracy, the rise time is generally
measured between 10% and 90% of the vertical pulse height.
For measurement, adjust the Y deflection coefficient using
its variable function (uncalibrated) together with the Y-POS.
control so that the pulse height is precisely aligned with the
0% and 100% lines of the internal graticule. The 10% and
90% points of the signal will now coincide with the 10% and
90% graticule lines. The rise time is given by the product of
the horizontal distance in div between these two coincident
points and the calibrated time coefficient setting. The fall
time of a pulse can also be measured by using this method.
The following figure shows correct positioning of the
oscilloscope trace for accurate rise time measurement.
With a time coefficient of 5ns/div (X x10 magnification active),
the example shown in the above figure results in a total
measured rise time of
t
tot
= 1.6div x 5ns/div : 10 = 8ns
When very fast rise times are being measured, the rise times
of the oscilloscope amplifier and of the attenuator probe has
to be deducted from the measured time value. The rise time
of the signal can be calculated using the following formula.
In this t
tot
is the total measured rise time, t
osc
is the rise time
of the oscilloscope amplifier (approx. 2.3ns), and tp the rise
time of the probe (e.g. = 2ns). If t
tot
is greater than 34ns,
then t
tot
can be taken as the rise time of the pulse, and calcu-
lation is unnecessary.
Calculation of the example in the figure above results in a
signal rise time
The measurement of the rise or fall time is not limited to the
trace dimensions shown in the above diagram. It is only
particularly simple in this way. In principle it is possible to
measure in any display position and at any signal amplitude.
It is only important that the full height of the signal edge of
interest is visible in its full length at not too great steepness
and that the horizontal distance at 10% and 90% of the
amplitude is measured. If the edge shows rounding or overshooting, the 100% should not be related to the peak values
but to the mean pulse heights. Breaks or peaks (glitches)
next to the edge are also not taken into account. With very
severe transient distortions, the rise and fall time measurement has little meaning. For amplifiers with approximately
constant group delay (therefore good pulse transmission
performance) the following numerical relationship between
rise time tr (in ns) and bandwidth B (in MHz) applies:
Connection of Test Signal
In most cases briefly depressing the AUTO SET causes a
useful signal related instrument setting. The following
explanations refer to special applications and/or signals,
demanding a manual instrument setting. The description of
the controls is explained in the section “controls and read-
out”.
Caution:
When connecting unknown signals to the oscilloscope input, always use automatic triggering and
set the input coupling switch to AC (readout). The
attenuator should initially be set to 20V/div.
Sometimes the trace will disappear after an input signal has
been applied. Then a higher deflection coefficient (lower input
sensitivity) must be chosen until the vertical signal height is
only 3-8div. With a signal amplitude greater than 160Vpp and
the deflection coefficient (VOLTS/DIV.) in calibrated
condition, an attenuator probe must be inserted before the
vertical input. If, after applying the signal, the trace is nearly
blanked, the period of the signal is probably substantially
longer than the set time deflection coefficient (TIME/DIV.).
It should be switched to an adequately larger time coefficient.
The signal to be displayed can be connected directly to the Y input of the oscilloscope with a shielded test cable such as
PR37AG, or reduced through a x10 o r x100 attenuator
probe. The use of test cables with high impedance circuits is
only recommended for relatively low frequencies (up to
approx. 50kHz). For higher frequencies, the signal source
must be of low impedance, i.e. matched to the characteristic
resistance of the cable (as a rule 50Ω). Especially when
transmitting square and pulse signals, a resistor equal to the
characteristic impedance of the cable must also be connected
across the cable directly at the Y-input of the oscilloscope.
When using a 50 Ω cable. When
transmitting square signals with short rise times, transient
phenomena on the edges and top of the signal may become
visible if the correct termination is not used. A terminating
resistance is sometimes recommended with sine signals as
well. Certain amplifiers, generators or their attenuators
maintain the nominal output voltage independent of frequency
only if their connection cable is terminated with the prescribed
resistance. If a
Type of signal voltage
11
Subject to change without notice
x10 or x100 attenuator probe is used, no termination is
necessary. In this case, the connecting cable is matched
directly to the high impedance input of the oscilloscope. When
using attenuators probes, even high internal impedance
sources are only slightly loaded (approx. 10MΩ II 12pF.
Therefore, if the voltage loss due to the
attenuation of the probe can be compensated by a
higher amplitude setting, the probe should always be used.
The series impedance of the probe provides a certain amount
of protection for the input of the vertical amplifier. Because
of their separate manufacture, all attenuator probes are only
partially compensated, therefore accurate compensation must
be performed on the oscilloscope (see Probe compensation).
Standard attenuator probes on the oscilloscope normally
reduce its bandwidth and increase the rise time. In all cases
where the oscilloscope bandwidth must be fully utilized (e.g.
for pulses with steep edges).
The probes mentioned have a HF-calibration in addition to
low frequency calibration adjustment. Thus a group delay
correction to the upper limit frequency of the oscilloscope is
possible with the aid of an 1MHz calibrator.
In fact the bandwidth and rise time of the oscilloscope are
not noticeably changed with these probe types and the
waveform reproduction fidelity can even be improved because
the probe can be matched to the oscilloscopes individual pulse
response.
If a x10 or x100 attenuator probe is used, DC input
coupling must always be used at voltages above
400V. With AC coupling of low frequency signals, the
attenuation is no longer independent of frequency,
pulses can show pulse tilts. Direct voltages are
suppressed but load the oscilloscope input coupling
capacitor concerned. Its voltage rating is max. 400 V
(DC + peak AC). DC input coupling is therefore of quite
special importance with a x100 attenuation probe
which usually has a voltage rating of max. 1200 V
(DC + peak AC). A capacitor of corresponding
capacitance and voltage rating may be connected in
series with the attenuator probe input for blocking
DC voltage (e.g. for hum voltage measurement).
With all attenuator probes, the maximum AC input voltage
must be derated with frequency usually above 20kHz.
Therefore the derating curve of the attenuator probe type
concerned must be taken into account.
The selection of the ground point on the test object is
important when displaying small signal voltages. It should
always be as close as possible to the measuring point. If this
is not done, serious signal distortion may result from spurious
currents through the ground leads or chassis parts. The
ground leads on attenuator probes are also particularly critical.
They should be as short and thick as possible. When the
attenuator probe is connected to a BNC-socket, a BNC-adapter,
should be used. In this way ground and matching problems
are eliminated. Hum or interference appearing in the measuring
circuit (especially when a small deflection coefficient is used)
is possibly caused by multiple grounding because equalizing
currents can flow in the shielding of the test cables (voltage
drop between the protective conductor connections, caused
by external equipment connected to the mains/line, e.g. signal
generators with interference protection capacitors).
Controls and Readout
The following description assumes that the instrument is not
set to “COMPONENT TESTER” mode.
If the instrument is switched on, all important settings are
displayed in the readout. The LED’s located on the front panel
assist operation and indicate additional information. Incorrect
operation and the electrical end positions of control knobs
are indicated by a warning beep.
Except for the power pushbutton (POWER), the calibrator
frequency pushbutton (CAL. 1kHz/1MHz), the focus control
(FOCUS) and the trace rotation control (TR) all other controls
are electronically selected. All other functions and their settings
can therefore be remote controlled and stored. Some controls
are only operative in storage mode or have different functions
in analog operation. See “STORAGE MODE ONLY”.
The front panel is subdivided into sections.
On the top, immediately to the right of the CRT screen,
the following controls and LED indicators are placed:
(1) POWER - Pushbutton and symbols for ON (I) and OFF
(O).
After the oscilloscope is switched on, all LEDs lit and an
automated instrument test is performed. During this
time the B&K logo and the software version are
displayed on the screen. After the internal test is
completed successfully, the overlay is switched off and
the normal operation mode is present. Then the last
used settings become activated and one LED indicates
the ON condition.
Some mode functions can be modified (SETUP) and/or
automated adjustment procedures (CALIBRATE) can be
called if the “MAIN MENU” is present. To enter this
menu the AUTO SET pushbutton must be pressed
constantly when the B&K logo is displayed until
“MAIN MENU” becomes visible. For further information
please note “MENU”.
(2) AUTO SET - Briefly depressing this pushbutton results
in an automatic signal related instrument setting (please
note “AUTO SET”), if the signal frequency and height
are suited for automatic triggering (AT). In Yt mode the
actual channel operating conditions (CH I, CH II or DUAL)
remain unchanged, whereas the time base is automatically set to A time base mode.
In case of XY or CT (Component Tester) operation, the
instrument is set to the last used Yt mode setting.
Automatic CURSOR supported voltage measurement
If CURSOR voltage measurement is present, the
CURSOR lines are automatically set to the positive and
negative peak value of the signal. The accuracy of this
function depends on the signal frequency and is also
influenced by the signal‘s pulse duty factor. If the signal
height is insufficient, the CURSOR lines do not change.
In DUAL mode the CURSOR lines are related to the
signal which is used for internal triggering.
Controls and Readout
Subject to change without notice
12
STORAGE MODE ONLY
Additionally, AUTOSET automatically selects refresh
mode (RFR) when SINGLE (SGL) or ROLL (ROL)
function is in operation.
Automatic CURSOR supported measurement
In contrast to analog mode, AUTO SET also causes an
automatic CURSOR line setting if time or frequency
measurement has been selected and at least one signal
period is displayed. Neither the signal frequency nor the
pulse duty factor have an effect on the accuracy when
CURSOR voltage measurement is chosen.
(3) RM - The remote control mode can be switched on or
off via the RS232 interface. In the latter case the “RM”
LED is lit and the electronically selectable controls on
front panel are inactive. This state can be left by
depressing the AUTO SET pushbutton provided it was
not inactivated via the interface.
STORAGE MODE ONLY
The RM LED is lit during signal transfer via the built in
RS232 interface. At this time the controls are inactive.
(4) INTENS - Knob with associated pushbutton and LEDs.
This control knob is for adjusting both the trace and
readout intensity. Turning this knob clockwise increases
and turning it counterclockwise decreases the intensity
of the selected function (A, RO resp. B).
The READ OUT pushbutton below is for selecting the
function in two ways.
Depending on the actual time base mode and the readout
(RO) not switched off, briefly pressing the READ OUT
pushbutton switches over the INTENS knob function
indicated by a LED in the sequences:
A - RO - A in condition A time base,
A - RO - B - A if alternate time base mode is present,
B - RO - B in condition B time base,
A - RO - B in XY mode and
A - RO - A in Component Tester (CT) mode.
Pressing and holding the READ OUT pushbutton swit-
ches the readout on or off. In readout off condition the
INTENS knob function can consequently not be set to
RO. Briefly pressing the pushbutton causes an error tone
if only A or B time base mode are present. If alternate
time base mode is used the switching sequence is A - B
- A.
Switching the readout off, may be required if interference
distortions are visible on the signal(s). Such distortions
may also originate from the chopper generator if the
instrument is operated in chopped DUAL mode.
In XY mode only A (for the signal) and RO can be
selected unless the readout is switched off. Then just
the A-LED is lit.
The readout is automatically switched off in COMPO-
NENT TEST mode and no other LED on the front panel
is lit except A.
All INTENS settings are stored after the instrument is
switched off.
The AUTO SET function switches the readout on and
selects A time base mode (A-LED lit). The INTENS
setting for each function is automatically set to the mean
value, if less intensity was previously selected.
(5) TR - The trace rotation control can be adjusted with a
small screwdriver (please note “trace rotation TR”)
(6) FOCUS - This control knob effects both the trace and
the readout sharpness.
(7) STOR. ON / HOLD - Pushbutton with two functions.
STOR. ON
Pressing and holding the pushbutton switches from
analog (Yt or XY) to storage mode and vice versa. If CT
(Component Tester) mode is present (only available in
analog mode), it must be switched off first to enable
switching over to storage mode.
The oscilloscope is in analog mode if none of the LED’s
associated with the STOR.MODE (9) pushbuttons are
lit and a pre- or post trigger value (PT...%) is not indicated
by the readout. Pressing and holding the STOR. ON
pushbutton switches over to the digital mode, but
without changing the channel operating mode (CH I, CH
II, DUAL, ADD and XY).
The actual signal capture mode is indicated by one of
the STOR. MODE-LED‘s (RFR - ENV - AVM - ROL) and
in addition displayed by the readout. In digital XY mode
the RFR-LED is lit and the readout indicates XY.
If digital SINGLE event (SGL) capture mode is selected,
all STOR. MODE-LED‘s are dark, but the readout displays
the pre- or post trigger value (PT...%).
Attention:
The time base ranges are different between analog and storage mode operation depending on
the operating mode!
In ALTernate and B time base mode the B time
coefficient can never be set to a larger value than
the actual A time coefficient. The following
information excludes the X magnifier factor.
Analog mode:
A time base from 500ms/div to 50ns/div.
B time base from 20ms/div to 50ns/div.
Storage mode:
A time base from 100s/div to 100ns/div,
B time base from 20ms/div to 100ns/div,
This results in the following behavior when switched
from analog to digital mode and vice versa:
1. If in analog mode, the time base has been selected
between 200ns/div and 50ns/div, then on switching
to digital mode the lowest available time coefficient
will be automatically selected, i.e. 100ns/div. If now
one switches back to analog mode without having
made any time base changes in the digital mode, then
the last time base selected in the analog mode is again
active (e.g. 50ns/div).
If on the other hand, the time base is changed after
switching over to digital mode (e.g. to 2µs/div). Then,
Controls and Readout
13
Subject to change without notice
when switched back to analog mode, the time base
in analog mode will be set to the value selected in the
digital mode (e.g. 2µs/div).
2. If a time base between 100s/div and 1s/div has been
set in the digital mode and the mode is switched to
analog, then the time base in analog mode is
automatically set to 500ms/div. The rest is as described
before.
The X-MAG x10 setting remains unchanged when
switched from analog to digital mode and vice versa.
STORAGE MODE ONLY
If by pressing and holding the STOR. ON / HOLD
pushbutton, the mode is switched to digital, then one
of the associated LED’s lights up. Which one,
depends on the last selected digital operation.
Exception
Switching over from analog SINGLE mode to digital mode sets the instrument automatically to
digital SINGLE mode.
For additional information regarding the digital mode,
see section STORAGE OPERATION.
HOLD
STORAGE MODE ONLY
Briefly pressing the STOR. ON / HOLD pushbutton
switches over between protected and unprotected mode
of the current memory contents.
The current contents of the memory are protected
against overwriting when HLD (HOLD) instead of
channel information (e.g. Y1... ) is displayed in the
readout. This prevents a change in the Yt mode setting,
but it is possible to select between DUAL (Yt) and XY
display by pressing the DUAL (23) pushbutton if one of
these modes was selected before activating HOLD.
If HOLD is switched off, one can observe how the
existing memory contents are successively overwritten
by new data especially with slow time base settings
and refresh mode. Protecting the memory contents in
the middle of a data acquisition process can result in an
irregularity at the junction of old (right) and new data
(left). This can be avoided by recording in single shot
mode (SGL), even though the input signal is repetitive.
At the end of a sweep, one can use HOLD to protect
the contents against being overwritten by an unintentional actuation of RESET (RES).
The signal in each of the current memory can be shifted
in the vertical direction (+/- 4div) with the corresponding
Y-POS r otary knob when HOLD is operative.
The original trace position will be lost when shifted
vertically, but this can be found again. To this end the Y-
POS knob in question must be rotated quickly. Once
the original position is reached, the trace does not shift
anymore although the knob is rotated further. Simultaneously a signal tone sounds. To shift the trace vertically again it will be required to stop rotating the knob
for at least about 2 seconds.
Attention!
The dynamic range limits of the A/D converter may
become visible if a Y -position shift is performed after
storage. This can affect those signal parts which were
originally above or below the screen.
(8) PTR / PK Det - Pushbutton with two functions.
Neither function is available in analog mode.
PTR
Briefly pressing selects the PRE- and POST -T rigger value.
The PRE TRIGGER function is used to capture signals
that occur prior to a trigger event, making the prehistory
visible. In contrast to this function, the POST TRIGGER
is used to capture signals occurring after the trigger
event, which could not be captured in “0%” pre trigger
condition. Due to the dependence on trigger events,
neither function is available in the trigger independent
modes XY and ROLL.
The actual PRE- or POST TRIGGER value is displayed
by the readout and changes each time the PTR
pushbutton is pressed briefly, in the following sequence:
PT0%, PT25%, PT50%, PT75%, PT100%, PT-75%, PT50%, PT-25% and back to PT0%.
The values refer to the X-axis (graticule) of the screen
display (10% = 1div).
The following description assumes that the X magnifier
(x10) is inactive and the signal display starts on the
leftmost vertical graticule line. It is also assumed that a
trigger mode (source, coupling) is chosen, in which the
trigger point symbol is displayed. In contrast to analog
mode, using pre trigger the trigger point symbol can be
shifted in X-direction.
PRE TRIGGER
0% PRE TRIGGER (readout ”PT0%”) means that the
signal display starts with the trigger event. The trigger
point symbol indicates this position. If the X-POS. control
is not in center position, an arrow pointing to the left
may be displayed. Then the X-POS. (19) control must
be turned clockwise until the arrow is no longer visible.
25% PRE TRIGGER (readout ”PT25%”) is achieved after
pressing the PTR pushbutton once. The signal display
starts with 25% prehistory and the trigger point symbol
is shifted 2.5 divisions to the right.
Each time the PTR pushbutton is pressed the PRE
TRIGGER value increases by 25% until 100% is reached.
If in 100% condition an arrow symbol is displayed in
addition to the trigger point symbol, the X-POS. control
should be turned ccw. to make the trigger point visible
on the screen.
The duration of the prehistory is determined by multiplying the time coefficient by the pre trigger value (in
divisions). E.g. 20ms/div x 7,5 div (= 75% pre trigger) =
150ms.
POST TRIGGER
In POST TRIGGER condition the trigger point is always
to the left of the screen and therefore not visible. The
trigger point symbol then only indicates the LEVEL
Controls and Readout
Subject to change without notice
14
setting. An additional arrow symbol which points to the
left is displayed to indicate post trigger operation. In
POST TRIGGER condition the arrow symbol does not
indicate a wrong X-POS. setting. A minus sign (-) placed
in front of the percentage value, is displayed by the
readout for POST TRIGGER mode indication.
Proceeding from 100% pre trigger, the instrument switches over to 75% POST TRIGGER (”PT-75%”) after
the PTR pushbutton is pressed. Then the trigger point
is 7.5 div to the left of the trace start on the screen.
This means that the signal capture starts 7.5 x time
deflection coefficient after the trigger event occurred.
Every time the PTR pushbutton is pressed the POST
TRIGGER value changes in 25% steps until PTR-25% is
active. When the PTR pushbutton is pressed again, both
post and pre trigger are switched off and the readout
indicates ”PT0%”.
Attention!
In time base settings from 100s/div to 50ms/div the
pre- or post trigger is automatically switched off
(”PT0%) if refresh (RFR), envelope (ENV) or average
(AVM) mode is active. This is to avoid excessive waiting times.
If the pre- or post trigger function is required in combination with those time coefficients, SINGLE (SGL) mode
operation must be used.
PK Det
Pressing and holding switches the peak value detection
(“PK Det” = peak detect) on or off. This function is
available only with deflection coefficients from 100s/div
to 5µs/div in combination with REFRESH, ENVELOPE,
ROLL or SINGLE modes. “PK Det” will be disabled
automatically if AVERAGE mode is active or a time
coefficient from 2µs/div to 100ns/div is chosen.
The “PK Det” function is indicated by the time coefficient
display in the readout. Switching “PK Det” on, changes
from e.g. “A:20ms” to “P:20ms” and consequently in
B time base mode from “B:100µs” to “P:100µs”. In
alternate (A and B) time base mode, the “PK Det”
function only affects the A time base and the readout
displays e.g. “P:20ms” and “B:100µs”.
In “PK Det” operation the sampling rate is always 40MS/
s and the signal will be sampled every 25ns. The advantage of this sampling method is as follows:
Without “PK Det” and a time coefficient of 100s/div,
the signal is sampled every 0.5 seconds (2 Samples/
second) and stored at a new address. A signal amplitude
change with a duration of e.g. 30ns appearing 0.2 seconds after the last sampling procedure will not be captured. In combination with “PK Det” the sampling
interval is reduced to 25ns and then the samples will be
evaluated and the most deviating value captured within
0.5s after the last storage procedure, will be stored at
the next address.
(9) STOR. MODE - Pushbuttons with associated LEDs.
These functions are not available in analog mode.
If digital SINGLE (SGL) mode has not been chosen,
one of the associated LEDs is lit. The signal capture and
display mode can be selected by pressing one of the
pushbuttons. The mode setting is indicated by one of
the LEDs (RFR, ENV, AVM and ROL) and also displayed
by the readout. The only exception is in XY storage
mode. Then the RFR-LED is lit and the readout displays
XY. No other signal capture and display mode can be
chosen in XY mode.
The desired Yt signal capture mode can be selected by
pressing the upper or lower STOR. MODE pushbutton.
The following description presumes that HOLD (HLD)
is not activated and the trigger conditions are met.
(9) RFR - stands for refresh operation. In this mode, as in
analog mode, periodically repeating signals can be
captured and displayed.
The signal acquisition is started by triggering the digital
time base. Then the previously captured and displayed
signal will be overwritten with the current signal. This
will be displayed until the digital time base is triggered
again. This is in contrast to analog operation where the
screen remains blank when the time base is not
triggered.
In refresh mode, the signal acquisition can be effected
with pre- or post triggering when a time base between
20ms/div and 100ns/div is selected. The pre triggering
or post triggering will be automatically switched off
(PT0%), with larger time coefficients (100s/div to 50ms/
div) in order to avoid excessive waiting times. If it is
required to measure with pre- or post trigger in this time
base range, one should select single shot (SINGLE =
SGL).
In XY digital mode the RFR-LED lights. It indicates a
continuous, trigger independent signal acquisition. The
trigger circuit is switched off.
(9) ENV - is the abbreviation for ENVELOPE operation.
In this mode the minimum and maximum values of the
signal during several signal acquisitions will be determined and displayed. Except for this display, the ENVELOPE operation is identical to the refresh operation.
Changes in the signal are easier to measure and are
more visible in ENVELOPE operation. This is valid not
only for amplitude changes but also for frequency
variations (Jitter).
The ENVELOPE evaluation begins anew when the
SINGLE (10) pushbutton is pressed briefly, to actuate
the RESET (RES) function.
Attention!
The pre- or post trigger will be automatically switched
off (PT0%) in the time base range from 100s/div to
50ms/div.
(9) AVM - indicates AVERAGE (mean value) mode.
This operation is effective when the AVM-LED lights up
and the readout displays AV... .
In this case also several signal acquisition scans are
required; hence, it is similar to Refresh operation. The
signal is averaged over the several acquisitions so that
Controls and Readout
Loading...