Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX 781.665.0780 - TestEquipmentDepot.com
5 MHz FUNCTION
GENERATOR
with DIGITAL DISPLAY
1
TEST INSTRUMENT SAFETY
WARNING
Normal use of test equipment exposes you to a certain amount of danger from electrical shock because testing must sometimes be
performed where exposed voltage is present. An electrical shock causing 10 millia mps 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 voltages pose an even greater threat because such voltage can more easily produce a lethal
current. Your normal work habits should include all accepted practices to prevent contact with exposed high voltage, and to steer current
away from your heart in case of accidental contact with a high voltage. You will sign ific ant ly re duce the r isk f acto r if y ou kn ow an d
observe the following safety precautions:
1. Don't expose high voltage needlessly. Remove housings and covers only when necessary. Turn off equipment while making test
connections in high-voltage circuits. Discharge high-voltage capacitors after remo ving 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; and 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 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.
(continued on inside back cover)
2
Instruction Manual
for
MODEL 4011A
5 MHz
FUNCTION
GENERATOR
with DIGITAL DISPLAY
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX 781.665.0780 - TestEquipmentDepot.com
3
TABLE OF CONTENTS
page
TEST INSTRUMENT ..................SAFETY inside front cover
The B+K Precision Mode l 4 0 1 1 A Function Generator
is a versatile signal source which combines several
functions into one unit. Additionally, the instrument
provides the added convenience of a built-in frequency
counter. This permits more accurate determination of
output frequency than is possible with a simple calibrated
dial. Coarse and fine tuning controls permit precision
settability of the output frequency. High stability assures
that the output frequency does not drift.
With this versatility, the unit has a vast number of
applications in both analog and digital electronics in the
engineering, manufacturing, servicing, educational, and
hobbyist fields.
INTRODUCTION
The heart of the function generator is a VCG (voltagecontrolled generator) that produces precision sine, square,
or triangle waves over the 0.5Hz to 5MHz range. This
encompasses subaudible, audio, ultrasonic, and RF
applications. A continuously variable dc offset allows the
output to be injected directly into circuits at the correct bias
level.
Variable symmetry of the output waveform converts the
instrument to a pulse generator capable of generating
rectangular waves or pulses, ramp or sawtooth waves, and
slewed sine waves.
In addition to the above features, an external signal may
be used to sweep the output frequency or control operating
frequency. This is useful in situations where an externally
controlled frequency is desirable.
5
FREQUENCY CHARACTERISTICS
Waveforms
Sine, Square, Triangle, ± Pulse, ± Ramp
Range
0.5Hz to 5MHz in 7 ranges
Resolution
4 digits
Tuning Range
Coarse: 10:1, Fine: ±5% of Coarse Setting
Variable Duty Cycle
15:85:15 Continuously Variable
Operating Modes
Normal, VCG (Voltage Controlled Generator)
Frequency Stability
Output frequency will not change more than 0.09% in 15
minutes after 1 hour warmup.
OUTPUT CHARACTERISTICS
Impedance
50 Ω ±10%
Level
20V p-p Open-circuit, 10V p-p into 50 Ω
Amplitude Control
Variable, 20dB range typical
SPECIFICATIONS
Attenuation
-20 dB ±1 dB
DC Offset
Preset: ±0.1V typical
Variable: ±10V open-circuit, ±5V into 50 Ω
SINE WAVE
Distortion
3% typical at 1kHz
Flatness
±5% (.45 dB)
SQUARE WAVE
Symmetry
0.5Hz to 100kHz ≤2%
Rise Time
≤20nS
TRIANGLE WAVE
Linearity
≥98% to 100kHz
6
SPECIFICATIONS
TTL OUTPUT
Level 0.8V to 2.4V
Rise Time ≤20nS
Duty Cycle 50% typical
DIMENSIONS (H x W x D)
10-3/8" x 3-3/8" x 11-7/16" (26.4cm x 8.6cm x 29.1cm)
WEIGHT
4 lb. (1.8 kg.)
ACCESSORIES
Instruction Manual
Output Cable, BNC to Alligator Clips
NOTE: Specifications and information are subject to change without notice. Please visit www.bkprecision.com for the most current product
information.
7
CONTROLS AND INDICATORS
FRONT PANEL (Refer to Fig. 1)
1. POWER Switch. Turns power on and off.
2. RANGE Switch. Selects output frequency range. Seven
ranges from 5Hz to 5MHz. Switch indicates maximum
frequency of range and is adjusted with COARSE
FREQUENCY control to 0.1 times the maximum. For
example, if the 500kHz range is selected, the output
frequency can be adjusted from 50kHz to 500kHz.
3. FUNCTION Switch. Selects sine, square, or triangle
waveform at OUTPUT jack.
4. OUTPUT LEVEL Control. Controls the amplitude of the
signal at the OUTPUT jack. Output level can be decreased
by approximately 20 dB with this control.
5. DC OFFSET Control. Enabled by the DC OFFSET
Switch (12). Clockwise rotation from center changes the
DC offset in a positive direction while counterclockwise
rotation from center changes the DC offset in a negative
direction.
6. OUTPUT Jack. Waveform selected by FUNCTION
switch as well as the superimposed DC OFFSET voltage
is available at this jack.
7. TTL/CMOS Jack. TTL or CMOS square wave,
depending on the position of the CMOS LEVEL
switch (13) is output at this jack. This output is
independent of the OUTPUT LEVEL and DC
OFFSET controls.
8. CMOS LEVEL Control. Rotating this control
clockwise increases the amplitude of the CMOS
square wave at the TTL/CMOS jack.
9. VCG Jack. Voltage Controlled Generator input.
Permits external control of generator output
frequency by a DC voltage input at this jack. A
positive voltage will decrease frequency.
10. DUTY CYCLE Control. Enabled by the DUTY
CYCLE Switch (14). Rotation from center position
adjusts the duty cycle of the main OUTPUT signal.
11. -20dB Switch. When engaged, the signal at the
OUTPUT jack is attenuated by 20dB.
12. DC OFFSET Switch. When engaged, enables
operation of the DC OFFSET control (5).
8
Figure 1. Model 4011A Controls and Indicators.
13. CMOS LEVEL Switch. When engaged, changes
the TTL signal to CMOS signal at the TTL/CMOS
jack.
14. DUTY CYCLE Switch. When engaged, enables
operation of DUTY CYCLE control (10).
15. FINE FREQUENCY Control. Vernier adjustment
of the output frequency for ease of setting frequency.
16. COARSE FREQUENCY Control. Coarse
adjustment of the output frequency from 0.1 to 1
times the selected range.
17. COUNTER DISPLAY. Displays frequency of internally
generated waveform.
18. GATE LED. Indicates when the frequency counter display is
updated. When the 50K through 5M ranges are selected, the
LED will flash 10 times per second (every 0.1 seconds).
When the 50 through 5K ranges are selected, the LED will
flash once every second and when the 5 range is selected, the
LED will flash every 10 seconds. As the LED turns off, the
display is updated.
19. Hz and KHz LED. Indicates whether the counter is reading
in Hz or kHz.
20 Inverter Switch
9
OPERATING INSTRUCTIONS
g
p
The B+K Precision Model 4011A Function Generator is a
versatile instrument, capable of producing a variety of output
waveforms over a broad range of frequencies. To gain a working
familiarity with the unit, it is recommended that it be connected
initially to an oscilloscope, so that the effects of the various controls
on the output waveforms can be observed. Use this manual as
required for reference until becoming accustomed to the operating
procedures.
FREQUENCY AND WAVEFORM SELECTION
l. Initially, verify that the DUTY CYCLE (14), CMOS LEVEL
(13), DC OFFSET (12), -20dB (11) switches are in the OUT
position (released). This will produce a symmetrical waveform
unaffected by the other controls.
2. Plug the unit into an appropriate power source and turn it on by
engaging the POWER switch (1).
3. Select the desired waveform (SINE, SQUARE, or TRIANGLE)
by engaging one of the FUNCTION switches (3). Phase
relationships of the waveforms are shown in Fig. 2.
4. Select the frequency of the waveform by engaging one of the
RANGE switches (2). The output frequency is displayed, along
with the appropriate measurement units, kHz or Hz (19), on the
LED display.
5. Rotate the COARSE (16) frequency control to quickly set the
output frequency to the approximate desired value. The FINE
(15) frequency control can then be used to easily set the output
to the specific desired value. The frequency selected is available
at the OUTPUT jack (6). In addition, a digital signal, either TTL
or CMOS is available at the TTL/CMOS jack (7) (refer to the
“TTL/CMOS OUTPUT” section of this manual).
10
Figure 2. Output Waveform and Phase Relationshi
6. Adjust the amplitude of the output as desired using the
OUTPUT LEVEL control (4). Rotation of this control
varies the amplitude from maximum to 20dB below
maximum. An additional attenuation of -20dB is
available by pushing in the -20dB switch (11). The
attenuation factors can be combined for a total of -40dB.
The maximum si
nal level is 10V p-p (into 50 Ω).
OPERATING INSTRUCTIONS
7. A superimposed DC component can be added to the output signal
by engaging the DC OFFSET switch (12) to enable operation of
the DC OFFSET control (5). Rotation of this control adds a
positive or negative DC component to the output signal. The DC
component introduced is independent of the OUTPUT LEVEL
control and can be varied by ±10 volts open circuited or ±5 volts
into 50Ω. The DC Offset does not affect the TTL/CMOS output
jack. The effect of DC OFFSET is shown in Fig. 3.
CONSIDERATIONS
1. l. Counterclockwise rotation of the COARSE frequency control
decreases the output frequency to approximately one-tenth of the
maximum for the range selected (10:1). For example, if the 50K
range is selected and the COARSE frequency control is set to
full counterclockwise, the output frequency is approximately
5kHz.
2. It is advisable to set the FINE frequency control to the
approximate center of its rotation before setting the COARSE
frequency control. This assures that the FINE control will not
reach its limit while trying to finalize the frequency setting.
3. The FINE frequency control provides approximately ±5%
frequency deviation from the COARSE control setting. This
provides vernier adjustment to easily set the frequency to a
precise value.
4. . When the 5Hz range is selected, the gate time is 10 seconds and
the display is updated once every 10 seconds. The result of a
frequency change will not be displayed until 10 seconds later.
Adjust the frequency in progressively smaller steps, waiting for
the display to update until the desired frequency is obtained.
5. When outputting square waves or when using the TTL output,
terminate the cable into 50Ω to minimize ringing. Also, keep
cables as short as possible.
11
Figure 3. Use of DC OFFSET Control
6. Remember that the output signal swing of the
generator is limited to ±10 volts open circuited or ±5
volts into 50Ω, and applies to the combined peak-topeak signal and DC offset. Clipping occurs slightly
above these levels. Fig. 3 illustrates the various
operating conditions encountered when using the DC
offset. If the desired output signal is large or if a large
DC offset is required, an oscilloscope should be used
to make sure that the desired signal is obtained without
undesirable clipping.
OPERATING INSTRUCTIONS
DUTY CYCLE CONTROL
The DUTY CYCLE control can be used to alter the
symmetry of the output waveform, to produce
waveshapes such as those shown in Fig. 4. For a
square wave, symmetry variation amounts to changing
the duty cycle (ratio of "high" to "low" time),
effectively converting the instrument into a pulse
generator. For a triangle wave, the result is a ramp, and
with a sine wave, a distorted waveshape called a
slewed sine is produced. The Model 4011A provides
for symmetry variation from 15% to 85%.
1. Select the waveform desired either SINE,
SQUARE or TRIANGLE.
2. Engage the DUTY CYCLE switch (14) and adjust
the DUTY CYCLE control (10) for the desired
waveshape. Clockwise rotation from center results
in an increase in square wave duty cycle, and
changes the sine and triangle waves as shown in
the top waveform of each pair of Fig. 4. Counterclockwise rotation results in the bottom waveform
in each pair.
3. Varying the duty cycle setting results in a slight
change in frequency. Adjust the COARSE and
FINE frequency controls as required.
Figure 4. Effects of Symmetry
Variation.
12
OPERATING INSTRUCTIONS
TTL/CMOS OUTPUT
The TTL/CMOS output jack provides a fast rise time square wave
output. Either a fixed TTL or a variable CMOS output level is
available. The output is positive with respect to ground and can be
used as an external sync pulse for oscilloscopes or as a variable
frequency signal source for exercising logic circuits. Because of the
fast rise time of this output, cable length should be minimized to limit
ringing and overshoot.
1. Select the desired frequency range and adjust the frequency
controls as required. The OUTPUT LEVEL and DC OFFSET
controls have no effect on the signal at the TTL/CMOS jack.
2.
When the CMOS LEVEL switch (13) is OFF, a TTL signal is
output at the TTL/CMOS jack. Select a CMOS signal by
engaging the CMOS LEVEL switch and adjust the level of the
signal by rotating the CMOS LEVEL control (8).
VOLTAGE CONTROLLED FREQUENCY OPERATION
The Model 4011A can be operated as a voltage-controlled generator
by using an external control voltage applied to the VCG INPUT jack.
The externally applied voltage will vary the frequency which is
preselected by the range switches and the frequency controls. Applying
approximately +l0 V with the COARSE control at full clockwise
decreases the output frequency by about 100 times (a 100:1 ratio).
1. Select the desired frequency range and waveform.
2. Set the starting frequency with the COARSE control. Apply a
positive DC voltage to the VCG INPUT jack (9) to decrease the
frequency. A voltage from 0 to +10V will cause the frequency to
decrease by a factor of 100 if the COARSE frequency control is
set at maximum CW rotation. For example, if the starting
frequency is 500kHz, applying +10V will change the output
frequency to 5kHz.
13
3. To operate the function generator as a sweep generator,
apply a positive going ramp signal to the VCG INPUT
jack. As the ramp voltage increases, the frequency
decreases. The rate of sweep can be adjusted by varying
the frequency of the ramp signal.
4. Specific frequencies can be selected by applying a fixed
dc voltage to the VCG INPUT jack or the frequencies can
be stepped by applying a stepped dc voltage.
5. Do not apply more than ±15 volts (dc or dc + ac peak) to
the VCG INPUT jack. Inputs of more than 15 volts will
not cause any further shift in the frequency and could
cause damage to the generator.
OUTPUT PROTECTION CONSIDERATIONS
Use care when connecting the function generator output to a
signal injection point. Excessive voltage at the point of signal
injection of the function generator can cause internal damage.
Under normal operation, the generator output should never be
connected to an external voltage other than low dc values that
can be matched with the DC OFFSET control. The Model
4011A is overload protected so that shorting the output, even
continuously, will not cause damage. A fuse has been added in
series with the OUTPUT jack to help protect the instrument
from damage by connection to excessive external voltage.
Damage of this type usually occurs by accidentally
connecting the output of the function generator to a voltage in
the equipment under test. The following protective measures are
strongly recommended:
1. The user should understand the equipment under test well
enough to identify valid signal injection points (i.e., the
base of a transistor, a logic input of a gate, etc.). The
voltage at valid signal injection points is rarely high enough
to damage the instrument.
OPERATING INSTRUCTIONS
2. If in doubt about the safety of a signal injection
point, measure the voltage present at the intended
point of signal injection before connecting the
function generator output to that point.
3. When applying the main output of the function
generator to a circuit point containing a dc level,
adjust the DC OFFSET control so that the dc level
at the main output matches the circuit voltage.
4. Connect the TTL output only to TTL-level circuits.
Connect the CMOS output only to CMOS circuits.
Measure the Vcc of the circuit under test and adjust
the CMOS LEVEL control as instructed in the
manual.
5. When the function generator is used by students or
other inexperienced users, the circuit of Fig. 5
could be added into your TTL output probe or test
clip set. It will protect the TTL output of the
generator against external voltages up to ±20 volts.
Figure 5. Circuit for Protection of TTL Output.
FUNCTION GENERATOR APPLICATIONS
GUIDEBOOK
B+K Precision offers a “Guidebook to Function
Generators” which describes numerous applications for this
instrument, including hook-up details. It also includes a
glossary of function generator terminology and an
explanation of function generator circuit operation. It may
be downloaded off our website at www.bkprecision.com
.
14
MAINTENANCE
The following instructions are for use by qualified service
personnel only. To avoid electrical shock, do not perform
servicing other than contained in the operating instructions
Remember that ac line voltage is present on line voltage input
circuits any time the instrument is plugged into an ac outlet, even
if turned off. Always unplug the function generator before
FUSE REPLACEMENT
1. Locate the fuse holder on the input line receptacle.
2. Remove the fuse holder and replace the fuse with an
equal value fuse
unless you are qualified to do so.
performing service procedures.
WARNING
INSTRUMENT REPAIR SERVICE
Because of the specialized skills and test
equipment required for instrument repair and
calibration, many customers prefer to rely upon
B+K PRECISION for this service. We maintain a
network of B+K PRECISION authorized service
agencies for this purpose. To use this service, even
if the instrument is no longer under warranty, follow
the instructions given in the WARRANTY
SERVICE INSTRUCTIONS portion of this manual.
There is a nominal charge for instruments out of
warranty.
15
CUSTOMER SUPPORT
1-800-462-9832
B+K Precision offers courteous, professional technical support before and after the sale of their test instruments. The following services are
typical of those available from our toll-free telephone number:
Technical advice on the use of your instrument.
Technical advice on special applications of your instrument.
Technical advice on selecting the best instrument for a given task.
Information on optional accessories for your instrument.
Information on instrument repair and recalibration services.
Replacement parts ordering.
Availability of service publications.
Information on other B+K Precision instruments.
Requests for a new B+K Precision catalog.
The name of your nearest B+ K Precision distributor.
Call toll-free 1-800-462-9832
Monday through Thursday, 8:00 A.M. to 5:00 P.M, Friday 8:00 A.M. TO 11:30 A.M.
Pacific Standard Time
(Pacific Daylight Time summer)
16
Service Information
Warranty Service: Please return the product in the original packaging with proof of purchase to the address below. Clearly state in writing
the performance problem and return any leads, probes, connectors and accessories that you are using with the device.
Non-Warranty Service: Return the product in the original packaging to the address below. Clearly state in writing the performance problem
and return any leads, probes, connectors and accessories that you are using with the device. Customers not on open account must include
payment in the form of a money order or credit card. For the most current repair charges please visit www.bkprecision.com
“service/repair”.
Return all merchandise to B&K Precision Corp. with pre-paid shipping. The flat-rate repair charge for Non-Warranty Service does not include
return shipping. Return shipping to locations in North American is included for Warranty Service. For overnight shipments and non-North
American shipping fees please contact B&K Precision Corp.
B&K Precision Corp.
22820 Savi Ranch Parkway
Yorba Linda, CA 92887
www.bkprecision.com
714-921-9095
Include with the returned instrument your complete return shipping address, contact name, phone number and description of
problem.
and click on
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX 781.665.0780 - TestEquipmentDepot.com
17
Limited Two-Year Warranty
B&K Precision Corp. warrants to the original purchaser that its products and the component parts thereof, will be free from defects in
workmanship and materials for a period of two years from date of purchase.
B&K Precision Corp. will, without charge, repair or replace, at its option, defective product or component parts. Returned product must be
accompanied by proof of the purchase date in the form of a sales receipt.
To obtain warranty coverage in the U.S.A., this product must be registered by completing a warranty registration form on
www.bkprecision.com
Exclusions: This warranty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or
repairs. The warranty is void if the serial number is altered, defaced or removed.
B&K Precision Corp. shall not be liable for any consequential damages, including without limitation damages resulting from loss of use.
Some states do not allow limitations of incidental or consequential damages. So the above limitation or exclusion may not apply to you.
This warranty gives you specific rights and you may have other rights, which vary from state-to-state.
6. 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 damag e to test instruments or the equipment under test may result from connecting the
ground lead of most test instru ments to a “hot cha ssis”. To test “h ot chassis” equipment, always connect an isolatio n transformer
between the ac outlet and the equipment under test. The B+K Precision Model TR-110 or 1604 Isolation Transformer, or Model
1653 or 1655 AC Power Supply is suitable for most applications. To be on the safe side, treat all two-wire ac equipme nt as “hotchassis” unless you are sure it has an isolated chassis or an earth ground chassis.
7. On test instruments or any equipment with a 3-wire ac power plug, use only a 3-wire outlet. This is a safety feature to keep the
housing or other exposed elements at earth ground.
8. Never work alone. Someone should be nearby to render aid if necessary. Training in CPR (cardio-pulmonary resuscitat ion) first
aid is highly recommended.
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176