Tektronix P6131 User manual

The test & measurement
equipment you need at
the price you want.
Alltest carries the world’s largest selection of
used/refurbished benchtop test & measurement
equipment at 50% the price of new.
O
Our equipment is guaranteed working, warrantied, and
available with certified calibration from our in-house staff
of technicians and engineers.
• 10+ full time technicians with over 150 years of
specialization
• 90 day warranty & 5 day right of return on all
equipment
•
• 1-3 year warranties for new and
premium-refurbished equipment
• Every unit tested to OEM specifications
• Satisfaction guaranteed
You have plans, we will help you achieve them.
Any project. Any budget.
Get a quote today!
CCall [phone] or email [e-mail].
t
Alltest Instruments, Inc.
500 Central Ave.
Farmingdale, NJ 07727
P: [phone]
F: [phone]
alltest.net
s
[e-mail]

Instruction Manual
P6131
10X Passive Probe
for 2400 Series Oscilloscopes
070-5514-03
*P070551403*
070551403
Warning
The servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not
perform any servicing unless you are qualified to
do so. Refer to all safety summaries prior to
performing service.
www.tektronix.com

Copyright ©Tektronix, Inc. All rights reserved.
Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.
Tektronix, Inc., P.O. Box 500, Beaverton, OR 97077-1000
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

WARRANTY
Tektronix warrants that the products that it manufactures and sells will be free from defects in materials and workmanship
for a period of one (1) year from the date of purchase from an authorized Tektronix distributor. If any such product proves
defective during this warranty period, Tektronix, at its option, either will repair the defective product without charge for
parts and labor, or will provide a replacement in exchange for the defective product. Batteries are excluded from this
warranty.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration of the
warranty period and make suitable arrangements for the performance of service. Customer shall be responsible for
packaging and shipping the defective product to the service center designated by Tektronix, shipping charges prepaid, and
with a copy of customer proof of purchase. Tektronix shall pay for the return of the product to Customer if the shipment is
to a location within the country in which the Tektronix service center is located. Customer shall be responsible for paying
all shipping charges, duties, taxes, and any other charges for products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate
maintenance and care. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting
from attempts by personnel other than Tektronix representatives to install, repair or service the product; b) to repair
damage resulting from improper use or connection to incompatible equipment; c) to repair any damage or malfunction
caused by the use of non-Tektronix supplies; or d) to service a product that has been modified or integrated with other
products when the effect of such modification or integration increases the time or difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THE LISTED PRODUCTS IN LIEU OF
ANY OTHER WARRANTIES, EXPRESS OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY
IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
TEKTRONIX’ RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND
EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY. TEKTRONIX
AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS
ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.

Contacting Tektronix
Product
support For questions about using Tektronix measurement products, call toll free in North America:
1-800-833–9200
6:00 a.m. – 5:00 p.m. Pacific time
Or contact us by e-mail:
[email protected]
For product support outside of North America, contact your local Tektronix distributor
or sales office.
Service
support Tektronix offers extended warranty and calibration programs as options on many products. Contact your local Tektronix distributor or sales office.
For a listing of worldwide service centers, visit our web site.
For other
information In North America: 1-800–833–9200
An operator can direct your call.
To write us
Web site
Tektronix, Inc.
P.O. Box 500
Beaverton, OR 97077-1000
USA
www.tektronix.com

P6131 Instruction Manual i
General Safety Summary
Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it. To avoid potential hazards, use this
product only as specified.
Only qualified personnel should perform service procedures.
Connect and Disconnect Properly. Do not connect or disconnect probes or test
leads while they are connected to a voltage source.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product. Consult the product manual for further ratings
information before making connections to the product.
The common terminal is at ground potential. Do not connect the common
terminal to elevated voltages.
Do not apply a potential to any terminal, including the common terminal, that
exceeds the maximum rating of that terminal.
Do Not Operate With SuspectedFailures. If you suspect there is damage to this
product, have it inspected by qualified service personnel.
Do Not Operate in Wet/DampConditions.
Do Not Operate in an Explosive Atmosphere.
Keep Product Surfaces Clean and Dry.
Terms in this Manual. The following terms may appear in this manual:
WARNING. Warning statements identify conditions or practices that could result
in injury or loss of life.
To Avoid Fire or
Personal Injury
Symbols and Terms

ii P6131 Instruction Manual
Service Safety Summary
Only qualified personnel should perform service procedures. Read this Service
Safety Summary and the General Safety Summary before performing any service
procedures.
Do Not Service Alone. Do not perform internal service or adjustments to this
product unless another person capable of rendering first aid and resuscitation is
present.

P6131 Instruction Manual 1
Operating Basics
The P6131 probe is a subminiature, 10X, passive probe designed specifically for
use with Tektronix 2400 Series oscilloscopes. It is fully compatible with the
Tektronix family of subminiature probe accessories. The P6131 is available
with 1.3 and 2 meter cable.
WARNING. To avoid electric shock when using the probe, do not touch the
metallic portions of the probe head while connected to a voltage source.
Lead Inductance
Inductance introduced by long leads can form resonant circuits that ring and
distort the true waveform if driven by signals containing significant frequency
components at or above resonance. To maintain optimum waveform fidelity,
keep the ground lead and signal input connection as short as possible.
Probe Compensation
Due to variations in oscilloscope input characteristics, probe low-frequency
compensation should be checked and or adjusted if you move the probe from one
oscilloscope input to another. Connect the probe tip to a 1 kHz square wave
signal (such as the oscilloscope calibrator output) and use a nonconductive
low-reactance alignment tool to adjust the compensation capacitor.
High-frequency compensation seldom requires adjustment. However, if the probe
has excessive high-frequency aberrations or insufficient bandwidth, you can
adjust the high-frequency compensation through holes in the compensation box
inner metal shield.
For complete low-frequency and high-frequency compensation adjustment
procedures, see page 10.

Operating Basics
2P6131 Instruction Manual
Grounding the Probe
Connect the probe to the instrument and connect the ground lead to ground
before making any measurement. Ensure that no part of the ground lead contacts
voltage in the circuit under test. Except for the probe tip and BNC center
conductor, all accessible metal (including the ground clip) is connected to the
BNC shell.
WARNING. To avoid electric shock when using the probe, keep your fingers
behind the finger guard on the probe body. See Figure 1 below.
Hand contact area
Finger guard
Figure 1: Probe finger guard and hand contact area

P6131 Instruction Manual 3
Specifications
The characteristics listed in Table 1 apply to P6131 probes installed on Tektronix
2445 and 2465 oscilloscopes or 7A42 plug-ins, unless otherwise noted.
Specifications apply when the instruments warm up for a period of at least
20 minutes in an environment that does not exceed the limits described in
Table 2 on page 5.
Table 1: Electrical characteristics1
Characteristic Description
Attenuation210X: ±1% at DC
Inputresistance2,3 10 MW±1% at DC
Inputcapacitance3
1.3 m 10.8 pF
2 m 13.5 pF
Compensationrange 14 pF to 18 pF
Signaldelay
1.3 m 6.3 ns ±100 ps
2 m 9.0 ns ±200 ps
System bandwidth (–3 dB) On a 2465 or 7A42: On a 2445:
1.3 m ≥300 MHz ≥150 MHz
2 m ≥250 MHz ≥150 MHz
Maximum Input Voltage4,5 300 V RMS CAT I or 300 V DC CAT I
150 V RMS CAT II or 150 V DC CAT II
100 V RMS CAT III or 100 V DC CAT III
425 V peak, @50% DF, <1 sec PW
750 V peak, @10% DF, <50 ms PW
See Figure 4 for voltage derating curve.
1Probe installed on Tektronix 150 MHz (or less) 2400 Series oscilloscope.
2Systemcharacteristic.
3Also see Figure 3.
4As defined in EN61010-1. See Certifications and compliances in Table 4
5RMS=Root Mean Square=rms=The square root of the average of the sum of the
squares of the instantaneous voltage in one cycle = .
300 VDC=300V RMS, 420 V Peak (sinewave)=300 V RMS See Figure 2.
ȍ(fxi)2ńn
Ǹ

Specifications
4P6131 Instruction Manual
@25% Duty Factor
=(1/2 Peak V) RMS
@50% Duty Factor
=(1.414 (Peak V)) RMS
Special case of square wave:
@20% Duty Factor
=[(VPeak)2(Duty Factor)] 1/2
Example: Maximum Input Voltage
=[(650 V Pk)2(.20)]1/2= 290 V RMS
0V
0V
0V
Figure 2: Maximum input voltage calculation example
RPand XP()
10M
1M
100K
10K
1M
1000.01 0.1 1 10 100 1000
Frequency (MHz)
Figure 3: Typical P6131 Xpand Rpversus frequency

Specifications
P6131 Instruction Manual 5
Frequency (MHz)
500
100
10 1 10 100
Voltage
(RMS)
Figure 4: Typical P6131 voltage derating versus frequency
Table 2: Environmental characteristics
Characteristic Description
Temperaturerange
Operating –15_C to 65_C (+5_F to 149_F)
Nonoperating –62_C to 85_C (–80_F to 185_F)
Humidity Five cycles (120 hr) at 95% to 97% relative
humidity, per Tektronixstandard 062-2847-00,
Class 3.
Referto MIL-E016400F,paragraph4.5.9
through4.5.9.5.1, class 4.
Altitude < 2000 meters
Table 3: Physical characteristics
Characteristic Description
Netweight11.3 meter, 108 g (3.8 oz)
2 meter, 129 g (4.8 oz)
Probecable length 1.3 meter (4.3 ft)
2 meter (6.6 ft)
1Includesaccessories

Specifications
6P6131 Instruction Manual
Table 4: Certifications and compliances
EC Declaration of
Conformity Compliance was demonstrated to the following specification as listed in the Official Journal of the European Communities:
Low Voltage Directive 73/23/EECas amended by 93/68/EEC:
EN61010-1/A2
EN61010-2-031:1994
Safetyrequirements for electrical equipment
formeasurement, control, and laboratoryuse
Particularrequirements for hand-held probe
assembliesfor electrical measurement and
test
Overvoltage
Category Category: Examples of Products in this Category:
CAT III Distribution-levelmains,fixedinstallation
CAT II Local-levelmains,appliances,portable
equipment
CAT I Signal levels in special equipment or parts of
equipment,telecommunications,electronics
PollutionDegree 2 Do not operate in environments where conductive pollutants may be
present.
Safety UL3111-1, First Edition & IEC61010-2-031, First Edition
CSA C22.2 No. 1010.1-92 & CAN/CSA C22.2 No. 1010.2.031-94
EN61010-1/A2
EN61010-2-031
PollutionDegree 2

P6131 Instruction Manual 7
Service Information
WARNING. The following instructions are for use by qualified service personnel
only. To avoid electrical shock, do not disassemble or maintain the probe while it
is connected to a signal source other than those specified in this procedure.
This section contains detailed performance checks, adjustments, and mainte-
nance procedures. These procedures use external traceable test equipment to
directly check warranted characteristics. If you substitute equipment, always
choose instruments that meet or exceed the minimum specified requirements.
Performance Verification Procedure
Use the following procedure to verify that P6131 probe performs as warranted.
For a list of the warranted specifications, see page 3.
Table 5 lists the test equipment needed to perform the performance verification
and adjustment procedures.
Table 5: Performance verification and adjustment test equipment
Description Minimumrequirements Example product
Oscilloscope2The P6131 probe is designed specifically for use
with Tektronix 2445 and 2465 oscilloscopes and
the 7A42 plug-in.
Tektronix 2445, 2465, or 7A42 plug-in3
Calibrationgenerator Pulse Rise Time: ≤1 ns
Amplitude:≥0.5 V into 50 
Rep Rate: 100 kHz
Accuracy:±0.25%
Directerror readout
Wavetek9500High-Performance
OscilloscopeCalibrator
Leveledsine wave generator Amplitude: adjustable to 1 Vp-p into 50 
Frequency range:1 MHz to 300 MHz2
Fixed 50 kHz reference
Precision coaxialcable 50 BNC, 36 inch length Tektronix012-0482-XX
10X attenuator 50 BNC Tektronix011-0059-XX
Adapter Subminiatureprobe-tip-to-BNC male Tektronix013-0195-XX

Service Information
8P6131 Instruction Manual
Table 5: Performance verification and adjustment test equipment (cont.)
Description ExampleproductMinimumrequirements
Termination 50 BNC Tektronix011-0049-XX
Low-reactancealignmenttool 2 inch shaft, .050 inch bit size Tektronix003-0675-XX
2To confirm the full bandwidth specification of the P6131 probe, use the following equipment: a Tektronix 2465 oscillo-
scope or 7904 oscilloscope with 7B92A time base and 7A42 vertical amplifier and a leveled sine wave generator capable
of 300 MHz output. If you use the probe with a Tektronix 2445 oscilloscope, the bandwidthspecification is lower; see
Table 1 on page 3.
3The maximum sensitivity of the 7A42 plug-in is 20 mV/division. When using the 7A42 to check P6131 probes, double the
amplitude settings in the procedures to follow.
NOTE. To ensure accurate measurements, warm up all test equipment for at least
20 minutes before beginning any performance verification or adjustment
procedure.
To check probe bandwidth do the following:
1. Connect the test setup as shown in Figure 5.
Leveled sine wave
generator
50 Termination
Subminiature
probe-tip-to-BNC
adapter Vertical input
P6131
probe head
Compensation
box
Test oscilloscope
Output
Figure 5: Bandwidth check setup
2. Set the test oscilloscope controls as follows:
Volts/Division 0.1 V (includes 10X probe attenuation)
Time/Division 1 ms
Input Coupling DC
Bandwidth Full
3. Set the leveled sine wave generator to 50 kHz.
Bandwidth Check

Service Information
P6131 Instruction Manual 9
4. Adjust the sine wave generator output amplitude to produce a 6-division
display on the test oscilloscope. Center the waveform on screen.
5. Set the sine wave generator to the high-frequency range and slowly increase
the variable frequency control until the display amplitude decreases to
4.2 divisions (–3 dB) on the oscilloscope.
6. Verify that the sine wave generator frequency readout is greater than or equal
to the values listed in Table 6 for your instrument.
Table 6: Probe bandwidths
Probe type 2465Oscilloscope
7A42 Plug-in 2445Oscilloscope
1.3 meter length 300 MHz 150 MHz
2.0 meter length 250 MHz 150 MHz
7. If the generator frequency readout is less than the specified value, perform
the low-frequency and high-frequency compensation adjustments beginning
on page 10.
8. Disconnect the test setup.
To check the probe attenuation accuracy do the following:
1. Connect the calibration generator standard amplitude output to the test
oscilloscope vertical input with the precision coax cable.
2. Set the calibration generator controls as follows:
Amplitude Standard
Output 50 mV
Frequency 1 kHz
3. Set the oscilloscope controls as follows:
Volts /Division 10 mV
Time/Division 10 ms
Input Coupling DC
Triggering Obtain a stable display
4. Adjust the calibration generator variable amplitude control to produce a
precise 5-division display on the oscilloscope.
5. Note the oscilloscope deflection error directly from the calibration generator
display for the calculation in step 9 below (Example: +1%).
Attenuation Accuracy
Check

Service Information
10 P6131 Instruction Manual
6. Remove the coax cable from the test setup. Connect the P6131 probe output
to the same vertical input on the oscilloscope.
7. Connect the probe tip through the probe-tip-to-BNC adapter to the standard
amplitude output of the calibration generator. (You must remove the light
gray probe-body shell before inserting the probe tip into the probe-tip-to-
BNC adapter.)
8. Set the calibration generator output amplitude to 0.5 V and fine tune the
amplitude to produce a precise 5-division display on the oscilloscope.
9. The deflection error indicated by the calibration generator must be within
0.75% of the error noted in step 5 above (probe attenuation accuracy of ±1%
minus the generator uncertainty). Example: if the error noted in step 5 is
+1%, the calibration generator display must now indicate between 0.25%
and 1.75%.
NOTE. You can also check the probe attenuation accuracy with an ohmmeter
having a 10 MWrange and ±0.05% or greater accuracy.
An attenuation accuracy of ±1.0% is assured if the oscilloscope input resistance
is 1 MW±0.55% (±0.5% tolerance plus 0.05% reading uncertainty) and the
probe-tip-to-output series resistance is indicated to be 9 MW±0.35% (±1.0%
attenuation accuracy minus ±0.6% input resistance uncertainty minus ±0.05%
reading uncertainty).
10. Disconnect the test setup.
Adjustment Procedure
This section contains procedures to adjust the P6131 probe low-frequency and
high-frequency compensations. Always perform the low-frequency compensation
adjustment before proceeding to the high-frequency adjustment.
For a list of test equipment needed to perform the adjustments, see Table 5 on
page 7.

Service Information
P6131 Instruction Manual 11
To adjust the probe low-frequency compensation do the following:
1. Connect the probe output to the test oscilloscope vertical input.
2. Set the oscilloscope controls as follows:
Volts /Division 0.1 V (includes 10X probe attenuation)
Time/Division 1 ms
Input Coupling DC
Bandwidth Full
3. Connect the probe input with hook tip to the oscilloscope calibrator output.
4. Set the oscilloscope triggering for a stable display. The square wave should
be five cycles in length, four divisions in amplitude, and centered on-screen.
5. Using the low-reactance alignment tool, adjust C2010 to optimize the square
wave front corner edge. See Figure 6 for the adjustment location; see
Figure 7 for waveform optimization criteria.
6. Disconnect the test setup.
Metal-shell version
C2010
Plastic-shell version
Figure 6: Low-frequency compensation adjustment locations
Low-Frequency
Compensation
Adjustment

Service Information
12 P6131 Instruction Manual
Over compensated
Under compensated
Correct
Figure 7: Low-frequency compensation, optimizing the waveform
To adjust the probe high-frequency compensation do the following:
1. Connect the positive-going fast-rise output of the calibration generator to the
test oscilloscope with the precision coax cable and 10X attenuator.
2. Set the oscilloscope controls as follows:
Volts /Division 10 mV (includes 10X probe attenuation)
Time/Division 0.02 ms
Input Coupling DC
Bandwidth Full
3. Set the calibration generator to produce a fast-rise output with a repetition
rate of 10 ms (100 kHz). Adjust the output amplitude to produce a 5 division
display on the oscilloscope.
4. Adjust the oscilloscope triggering for a stable display and center the
waveform on screen.
5. Note the pulse shape and system aberrations for analysis in step 10.
6. Remove the precision coax cable from the test setup.
7. Remove the probe compensation box cover as described below.
Metal shell version: Unscrew the compensation box retainer nut
approximately two complete turns and lift the cover out and up. Press
the cable connector in firmly and retighten the retainer.
Plastic shell version: Pry off the darker portion of the plastic shell by
inserting your thumbnails into the seam between the two cover pieces;
then remove the lighter portion from the inner metal shield.
High-Frequency
Compensation
Adjustment

Service Information
P6131 Instruction Manual 13
8. Connect the probe output to the oscilloscope vertical input.
9. Connect the probe tip through the probe-tip-to-BNC adapter and a 50 W
termination to the positive-going fast-rise output of the calibration generator.
(The light gray probe-body shell must be removed before inserting the probe
tip into the probe-tip-to-BNC adapter.)
10. Verify that the high-frequency aberrations do not exceed +6% (5.30
divisions), –6% (4.70 divisions), or 9% (0.45% division) peak to peak, in
addition to the system aberrations noted in step 5 above.
11. If the probe aberrations are within tolerance, proceed to step 14 below. If the
probe aberrations are not within tolerance, continue with step 12 below.
12. Adjust R2021 for the best overall waveform flat response. See Figure 8 for
the location of all adjustments.
13. Adjust R2020, R2010, and C1010 for the best corner response without
ringing. See Figure 9 for the waveform area effected by each adjustment.
NOTE. High-frequency compensation adjustments affect probe bandwidth.
Following the compensation adjustments, verify the probe bandwidth specifica-
tion using the procedure on page 8. A small overshoot on the leading edge of
the pulse may be tolerated in order to meet the bandwidth specification. The
overshoot should not exceed the typical aberrations described in step 10 above.
14. Reinstall the compensation box cover by performing the procedure described
in step 7 above in reverse order.
15. Disconnect the test setup.