Tektronix P6248 Service Manual

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P6248

1.7 GHz (Typical)

ZZZ

Differential Probe

Service Manual

*P071057304*

071-0573-04

P6248

1.7 GHz (Typical)

ZZZ

Differential Probe

Service Manual

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

071-0573-04

Copyright © Tektronix. All rights reserved. Licensed software products are owned by Tektronix or its subsidiaries or suppliers, and are protected by national copyright laws and international treaty provisions.

Tektronix p roducts are covered by U.S. and foreign patents, issued and pending. Information in this publication supersedes that in all previously published material. Speciﬁcations and price change privileges reserved.

TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

KlipChip, TwinFoot, TwinTip, and VariTip are trademarks of Tektronix, Inc.

Contacting Tektronix

Tektronix, Inc. 14200 SW Karl Braun Drive P.O . Bo x 500 Beaverton, OR 97077 USA

For product information, sales, service, and technical support:

In North America, call 1-800-833-9200. World wide, vi s it www.tektronix.com to ﬁnd contacts in your area.

Warranty

Tektronix warrants that this product will be free from def ects in materials and workmanship for a period o f one (1) year from the date of shipment. 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. Parts, modules and replacement products used by Tektronix for warranty work may be n the property of Tektronix.

ew or reconditioned to like new performance. All replaced parts, modules and products become

In order to o the warranty p eriod 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, with shipping charges prepaid. 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 result 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 PRODUCT 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.

TRONIX’ RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE

TEK 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.

[W2 – 15AUG04]

btain service under this warranty, Customer must notify Tektronix of the defect before the expiration of

ing from attempts by personnel other than Tektronix representatives to install, repair or service the product;

Table of Contents

General Safety Summary ......................................................................................... iii

Service Safety Summary............................ ................................ ............................... v

Preface ............................................................................................................. vii

Related Manuals ........ ................................ ................................ ..................... vii

Speciﬁcations .................. ................................ ................................ ..................... 1

Warranted Characteristics..................................................................................... 1

Typical Characteristics ..... ................................ ................................ ................... 2

Nominal Characteristics....................................................................................... 4

Performance Veriﬁcation ........... ................................ ................................ ............... 5

Equipment Required........................................................................................... 5

Preparation........................................... .................................. ......................... 6

Output Offset Voltage ............ ................................ .................................. ........... 7

DC Attenuation Accuracy .................................................................................... 8

Differential Signal Range ...................... ................................ ............................... 9

Rise Time .......... ................................ .................................. .......................... 11

Common-Mode Rejection Ratio .......... ................................ .................................. 14

TEKPROBE Communication (Operational Check) ...................................................... 17

Adjustment Procedures ........................................................................................... 19

Equipment Required.......................................................................................... 19

Adjustment locations ......................................................................................... 20

Offset (preliminary) .............. .................................. ................................ .......... 21

Gain .. ................................ ................................ .................................. ........ 22

Offset (Final) .................................................................................................. 23

DC CMRR..................................................................................................... 24

AC CMRR..................................................................................................... 26

Maintenance........................................................................................................ 27

Cleaning ....................................................................................................... 27

Replacing TEKPROBE Interface Pins ..................................................................... 27

Removing and Replacing the TEKPROBE Interface Collar....................................... ...... 28

Options........................................ ................................ ................................ ...... 29

Replaceable Parts .................................................................................................. 31

Appendix A: Alternate Veriﬁcation Procedures................ ................................ ................ 37

Equipment Required.......................................................................................... 37

Preparation........................................... .................................. ........................ 38

CMRR (Common-Mode Rejection Ratio) ....... .................................. ........................ 38

P6248 1.7 GHz Differential Probe Service Manual i

Table of Contents

List of Figure

Figure 1: Typical Common-Mode Rejection Ratio (÷1 and ÷10 attenuation) .... ........................... 3

Figure 2: Ty

Figure 3: Dimensions of probe head and compensation box .................................................. 4

Figure 4: Setup for the output offset voltage test .......... .................................. ................... 7

Figure 5: Setup for differential-mode tests ......... ................................ ............................. 9

Figure 6: Test system rise time setup.............................. ................................ .............. 11

Figure 7: Rise time setup for test system with probe.......................................................... 12

Figure 8:

Figure 9: Adjustment locations ...................... .................................. .......................... 20

Figure 10: Setup for the offset adjustment...................................................................... 21

Figure 11: Setup for gain adjustment............................................................................ 22

Figure 12: Setup for DC CMRR and AC CMRR adjustments ............................................... 24

Figure 13: Replacing TEKPROBE interface pins ............................................................. 27

e 14: Replacing the TEKPROBE collar .................................................................. 28

Figur

Figure 15: P6248 replaceable parts.................... ................................ .......................... 31

Figure 16: P6248 standard accessories.......................... ................................ ................ 32

Figure 17: P6248 optional accessories .................. .................................. ...................... 34

Figure 18: Normalizing the setup................................................................................ 38

Figure 19: Setup for the CMRR tests ........................................................................... 39

pical differential input impedance versus frequency............................................. 3

Setup for CMRR test ...................... ................................ ............................ 15

ii P6248 1.7 GHz Differential Probe Service Manual

General Safety Summary

General Safet

To Avoid Fi

re or Personal

Injury

ySummary

Review the fo this product or any products connected to it.

To avoid pot

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.

Ground the Product. This product is indirectly grounded through the grounding conductor of the mainframe power cord. To avoid electric shock, the grounding conductor must be connected to earth ground. Before making connections to the input or output terminals of the product, ensure that the product is properly grounded.

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

mation before making connections to the product.

infor

Connect the probe reference lead to earth ground only.

llowing safety precautions to avoid injury and prevent damage to

ential hazards, use this product only as speciﬁed.

Do Not Operate Without Covers. Do not operate this product with covers or panels removed.

Do Not Operate With Suspected Failures. If you suspect that there is damage to this product, have it inspected by qualiﬁed service personnel.

Avoid Exposed Circuitry. Do not touch exposed connections and components when power is present.

Do Not Operate in Wet/Damp Conditions.

Do Not Operate in an Explosive Atmosphere.

eep Product Surfaces Clean and Dry.

Provide Proper Ventilation. Refer to the manual’s installation instructions for

details on installing the product so it has proper ventilation.

P6248 1.7 GHz Differential Probe Service Manual iii

General Safety Summary

TermsinthisManual

Symbols and Terms on the

Product

These terms may

WARNING. Warning statements identify conditions or practices that could result

in injury or loss of life.

CAUTION. Caution statements identify conditions or practices that could result in

damage to this product or other property.

These terms may appear on the product:

DANGER in the marking.

WAR NI N G read the marking.

CAUTIO

The following symbol(s) may appear on the product:

appear in this manual:

dicates an injury hazard immediately accessible as you read

indicates an injury hazard not immediately accessible as you

N indicates a hazard to property including the product.

iv P6248 1.7 GHz Differential Probe Service Manual

Service Safety Summary

Service Safet

y Summary

Only qualiﬁe Safety Summary and the General Safety Summary before performing any service procedures.

Do Not Service Alone. Do not perform internal service or adjustments of this product unless another person capable of rendering ﬁrst aid and resuscitation is present.

Disconnect Power. To avoid electric shock, switch off the instrument power, then disconnect the power cord from the mains power.

UseCareWhenServicingWithPowerOn. Dangerousvoltagesorcurrentsmay exist in disconnect test leads before removing protective panels, soldering, or replacing components.

To avoid electric shock, do not touch exposed connections.

d personnel should perform service procedures. Read this Service

this product. Disconnect power, remove battery (if applicable), and

P6248 1.7 GHz Differential Probe Service Manual v

Service Safety Summary

vi P6248 1.7 GHz Differential Probe Service Manual

Preface

Related Manuals

This manual contains speciﬁcations and service information for the P6248 differential probe.

For operating information, refer to the P6248 Instructions (071-0566-XX).

P6248 1.7 GHz Differential Probe Service Manual vii

Preface

viii P6248 1.7 GHz Differential Probe Service Manual

Speciﬁcations

The speci ﬁ cations in the following tables apply to a P6248 differential probe installed on a Tektronix TDS694C oscilloscope. When the probe is used with another osci

lloscope, the oscilloscope must have an input impedance of 50 Ω.The probe must have a warm-up period of at least 20 minutes and be in an environment that does not exceed the limits described in the environmental speciﬁcations table. Speciﬁcations for the P6248 differential probe fall into three categories: warranted, typical, and nominal characteristics.

Warrante

d C haracteristics

Warranted characteristics describe guaranteed performance within tolerance limits or certain type-tested requirements. (See Table 1.) Warranted characteristics that hav symbol.

Table 1: Warranted electrical characteristics

Characteristic Description

accuracy

Maximum nondestructive input voltage

rang

Comm range (DC coupled)

voltage

Rise time (probe only)

rejection ratio

Bandwidth (probe only) DC to ≥1.5 G Hz (-3dB)

echecksinthePerformance Veriﬁcation section are marked with the

DC attenuation

Differential signal

e (DC coupled)

on-mode signal

Output offset

mon-mode

Com

±2% for input voltages ±750 mV (÷1) and ±7.5 V (÷10)

r input voltages ±850 mV (÷1) and ±8.5 V (÷10)

±5% fo

±25 V

(DC + peak AC)

±8.5 V at attenuation setting of ÷10 ±850 mV at attenuation setting of ÷1

±7 V

±10mV(+20to+30ºC,+68to+86ºF) ±50 mV (0 to +50 ºC, +32 to +122 ºF)

<265 ps

45 dB at 1 MHz in ÷10 25 dB at 100 MHz in ÷10 20 dB at 500 MHz in ÷10 18 dB at 1 GHz in ÷10 60 dB at 1 MHz in ÷1 38 dB at 100 MHz in ÷1 35 dB at 500 MHz in ÷1 30 dB at 1 GHz in ÷1

between signal and common of the same channel

P6248 1.7 GHz Differential Probe Service Manual 1

Speciﬁcations

Typical Characteristics

Table 1: Warranted electrical characteristics (cont.)

Characteristic Description

Temperature

Humidity

Operating: 0 to +50 ºC (+32 to +86 ºF),

0 to +60 ºC (+32 to +122 ºF) Nonoperating: -55 to +75 ºC (-131 to +167 ºF)

(probe head)

Operating: 0-90% RH, tested at +30 to +50 ºC (+68 to +122 ºF) Nonoperating: 0-90% RH, tested at +30 to +60 ºC (+68 to +140 ºF)

See warning that follows.

WARNING. To avoid a burn hazard at high ambient temperatures, do not touch

the probe with bare hands at operating temperatures above +50 °C (+122 °F) or at nonoperating temperatures above +70 °C (+158 °F). Allow sufﬁcient time for the p

robe to cool before handling.

Typical characteristics describe typical but not guaranteed performance. (See Table 2.)

Table 2: Typical electrical characteristics

acteristic

Char

ferential input

Dif resistance, DC coupled

Common-mode input

sistance, DC coupled

fferential input

Di capacitance

Common-mode input capacitance

Harmonic distortion

Differential offset range ±700 mV (÷1 range), ±7 V (÷10 range)

Common mode rejection ratio

Random noise

Input impedance

Pass band ripple

Bandwidth (probe only) DC to ≥1.7 GHz (- 3dB) @ ≤27 ºC (÷1 range)

Rise time (probe and oscilloscope)

ription

Desc

kΩ ±2%

200

100 kΩ ±2%

<1 pF at 1 MHz

2pFat1MHz

≤1.5% measured using 354 mV

RMS

(or 1.0 V

(See Figure 1 on page 3.)

<50 nV/ √Hz @100 MHz

(See Figure 2 on page 3.)

≤ ±0.5 dB to 850 MHz (deviation from a nominal slope)

DC to ≥1.85 GHz (- 3dB) @ ≤27 ºC (÷10 range)

<265 ps

) output at 100 MHz

P-P

2 P6248 1.7 GHz Differential Probe Service Manual

Speciﬁcations

Figure 1: Typical Common-Mode Rejection Ratio (÷1 and ÷10 a ttenuation)

Figure 2: Typical differential input impedance versus frequency

P6248 1.7 GHz Differential Probe Service Manual 3

Speciﬁcations

Table 3: Typica

Characteristic Description

Dimensions, i connection

Dimensions, box

Dimensions, head

Dimensions cable

Unit weight (probe only) 160 g (5.4 oz)

l mechanical characteristics

nput

control

probe

, output

0.63 mm (0.025 in) square pin on 2.54 mm (0.100 in) centers

107 mm × 41 mm × 26 mm (4.2 in × 1 .6 in × 1.0 in)

78 mm × 12 mm × 9.3 mm (3.0 in × 0.47 in × 0.36 in)

1.2m(47in)

Nominal Characteristics

Figure 3: Dimensions of probe head and compensation box

Nominal characteristics describe guaranteed traits, but the traits do not have tolerance limits. (See Table 4.)

Table 4: Nominal electrical characteristics

Characteristic Description

Input conﬁguration Differential ( two inputs, + and - ), with case ground

Output coupling DC

Attenuation settings ÷1 and ÷10

Termination

Terminate output into 50 Ω

4 P6248 1.7 GHz Differential Probe Service Manual

Performance Veriﬁcation

Use the following procedures to verify the warranted speciﬁcations of the P6248 Differential Probe. Before beginning these procedures, photocopy the test record and use it to r interval is one year.

ecord the performance test results. The recommended calibration

These proce

dures tes t the following speciﬁcations:

Output offset voltage

DC attenuation accuracy

Differential signal range

Rise time

Common mode rejection ratio

Equipment R equired

The equipment required to perform the performance veriﬁcation procedure is listed below. (See Table 5.) The types and quantities of connectors may v ary depending on the speciﬁc equipment you use.

NOTE. If you cannot obtain a network analyzer, refer to the appendix for

procedures that do not require a network analyzer to perform the CMRR tests.

page 37, Alternate Veriﬁcation Procedures.)

(See

Table 5 : Test equipment

Description Minimum requirements Example product

Calibrated DC voltage source (2 required)

DMM (2 required)

Network analyzer

Digitizing oscilloscope with TEKPROBE interface

Oscilloscope with sampling head

TEKPROBE Power Supply

BNC cables (2) 50 Ω,42inch

SMA cables (2) 50 Ω

Adjustable from 0 V to ≥17 V. Outputs must be isolated from earth ground. DC bench supplies monitored w ith DMM are adequate.

DC Accuracy ≥ 0.5% on range to measure 8.5 V, averaging mode.

100 kHz to ≥2 GHz, with cables and adapters to BNC male

Fully compatible with TEKPROBE i nterface (needed only for functional check of the TEKPROBE interface)

Tektronix Type 1103 Tektronix Type 1103

Tektronix PS280

Tektronix DMM916

Hewlett-Packard 8753D

Tektronix TDS500, TDS600, or TDS700 series oscilloscope

Tektronix 11800 series oscilloscope with SD-24

012-0057-01

015-0562-00

P6248 1.7 GHz Differential Probe Service Manual 5

Performance Veriﬁcation

Table 5 : Test equipment (cont.)

Description Minimum requirements Example product

Banana-to-banana patch cords (3)

Adapter (3) Dual-male-banana-to-female BNC

Adapter (2) BNC male to dual binding post

0.025" square pins (3)

Precision in-line BNC termination 50 Ω ±0.1%

Probe ground lead

Adapter

Adapter (2) SMA Female-to-BNC male

digit part numbers are Tektronix part numbers.

Nine-

2red

1black

Approximately 0.75 inch long, smooth, gold plated. 131-1614-00

(included in the standard probe tip accessory kit)

Y-lead (included in the standard probe tip accessory kit)

BNC-to-probe tip

SMA Male-to-male

012-0031-00

012-0039-00

103-0090-00

103-0035-00

011-0129-00

196-3437-XX

196-3434-XX

679-4094-XX

015-1011-00

015-0572-00

Preparation

pare the equipment as follows:

Pre

1. Connect the Y-lead adapter to the inputs of the probe and the ground lead to probe ground. (For a description of these accessories, refer to the list of

the standard accessories.)

tach the probe to the 1103 TEKPROBE power supply.

2. At

3. If nec essary, set the line selector of the 1103 power supply to the correct

oltage.

4. Turn on the 1103 power supply.

5. Set the 1103 offset to off (button not illuminated).

6. Allow the probe and test equipment to warm up for 20 minutes at an ambient

temperatureof20ºCto30ºC(68ºFto86ºF).

Perform the veriﬁcation procedures in order.

6 P6248 1.7 GHz Differential Probe Service Manual

Performance Veriﬁcation

Output Offset

Voltage

1. Connect the probe as shown in the ﬁgure. (See Figure 4.)

Figure 4: Setup for the output offset voltage test

2. Set the probe to ÷10 attenuation.

3. Ver i

4. Change the probe attenuation to ÷1.

5. Verify that the output voltage is ≤ ±10 mV.

6. Keep the output connections for the next procedure.

fy that the output voltage is ≤ ±10 mV.

P6248 1.7 GHz Differential Probe Service Manual 7

Performance Veriﬁcation

DC Attenuatio

n Accuracy

1. Connect the probe input to the Y-lead adapter and then to the DC source.

2. Set the probe to ÷10 attenuation.

3. Set the input voltage on the DC source to approximately 5 V. Record the

4. Record the output voltage as V

5. Set the input voltage on the DC source to approximately 1 V. Record the

6. Record the output voltage as V

7. Calculate the attenuation as follows: (V

8. Verify t

9. Set input voltage on the DC source to approximately 0.5 V. Record the actual

10. Change the attenuation to ÷1.

11. Record the output voltage as V

Monitor the source voltage with the DMM.

actual voltage as V

out

1-Vin2) ÷ (V

hat the attenuation is in the range of 9.8 to 10.2.

voltag

easV

out

1-V

out

2).

12. Set input voltage on DC source to approximately 0.1 V. Record the actual

voltage as V

13. Record the output voltage as V

14. Calculate the attenuation as follows: (V

out

1-Vin2) ÷ (V

1-V

out

2).

15. Verify that the attenuation is in the range of 0.98 to 1.02.

16.Ke

ep the output connections for the next procedure.

8 P6248 1.7 GHz Differential Probe Service Manual

Performance Veriﬁcation

Differential

Signal Range

This procedure directly veriﬁes the differential signal range and indirectly veriﬁes the c ommon-mode signal range.

1. Connect the probe as shown in the ﬁgure. (See Figure 5.) Use the adapters and patch cords as necessa ry to make the connections. Use square pins to connect the ground lead and Y-lead to the power supplies.

Figure 5: Setup for differential-mode tests

2. Set the probe to ÷10 attenuation.

3. Set the common mode source to 7.0 V ±50 mV.

4. Set the differential mode source to 8.5 V ±100 mV. Record the actual voltage

as V

5. Measure and record the output voltage as V

÷V

6. Calculate attenuation as V

out

7. Verify that the attenuation is in the range of 9.5 to 10.5.

8. Remove the Y-lead adapter from the probe and reverse the connection (black

to +, red to -).

P6248 1.7 GHz Differential Probe Service Manual 9

Performance Veriﬁcation

9. Measure and rec

ord the output voltage as V

10. Calculate attenuation as V

÷(-V

out

11. Verify that the attenuation is in the range of 9.5 to 10.5.

12. Set the differential mode source to 0.85 V ±10 mV. Record the actual voltage

as V

13. Make sure that the common mode source is still set to 7.0 V ±50 mV.

14. Set the probe attenuation to ÷1.

15. Measure and record the output voltage as V

16. Calculat

e attenuation as V

÷(-V

out

17. Verify that the attenuation is in the range of 0.95 to 1.05.

18. Remove the Y-lead adapter from the probe and reverse the connection again

(red to +, black to -).

19. Measure and record the output voltage as V

÷V

20. Calculate the attenuation as V

out

21. Verify that the attenuation is in the range of 0.95 to 1.05.

22. Remove all connections.

10 P6248 1.7 GHz Differential Probe Service Manual

Rise Time

Performance Veriﬁcation

This procedure veriﬁes the probe meets rise time speciﬁcations.

You ﬁrst measure the rise time of the test system alone, and then you measure the rise time with the probe in the circuit. The probe rise time is then calculated from the two measured rise times.

1. Connect the test equipment as shown. (See Figure 6.)

2. Initialize the oscilloscope and set the CH1 and CH2 sampling heads to ON.

3. Set the TDR

function o n CH2 to ON.

4. Set the triggering to Internal Clock.

5. Adjust the oscilloscope:

Press Autoset.

Vertical sensitivity to 50 mV/div.

Vertical positioning to center the signal on screen.

Horizo

ntal sensitivity to 500 ps/div.

Horizontal positioning to place the rising edge of the signal where it

es the second vertical and center horizontal graticule lines.

cross

6. Use the oscilloscope measurement capability to display rise time. Rise time

termined from the 10% and 90% amplitude points on the waveform.

is de Record the rise time a s t

he measurement reading is not stable, use Average mode (32 Averages) to

If t

improve stability.

e system rise time (t

) that you measured in step 6 represents the rise time of

the test system without the probe. The system rise time is used to calculate the probe rise time (t

) in steps 22 and 31.

Figure 6: Test system rise time setup

P6248 1.7 GHz Differential Probe Service Manual 11

Performance Veriﬁcation

The following s (See Figure 7.) The system and probe rise time (t and 30 is used to calculate the probe rise time (t

teps instruct you to assemble the test setup that includes the probe.

) that you measure in steps 21

s+p

) in steps 22 and 31.

7. Disconnect the BNC-SMA adapter from the CH 1 input of the 1103.

8. Disconnect

the SMA cable from the CH 2 input of the SD-24.

9. Connect the probe to the 1103 power supply channel 1 input.

10. Set the offset control on channel 1 of the 1103 power supply to off.

11. Connect the SMA Male-to-male adapter to the CH 2 input of the SD-24.

12. Connect the BNC-SMA adapter to the SMA Male-to-male adapter.

13. Connect the BNC-probe tip adapter to the BNC-SMA adapter.

14. Connect

the probe input to the DM pins on the BNC-probe tip adapter. Observe proper polarity; the + side of the probe should be on the center square pin o f the probe tip adapter.

The test setup should now appear as shown. (See Figure 7.)

Figure 7: Rise time setup for test system with probe

12 P6248 1.7 GHz Differential Probe Service Manual

Performance Veriﬁcation

15. Set the probe at

tenuation t o ÷1.

16. Press Autoset on the oscilloscope.

17. Adjust the oscilloscope vertical sensitivity to 50 mV/div.

18. Adjust the oscilloscope vertical positioning to center the signal on screen.

19. Adjust the oscilloscope horizontal sensitivity to 500 ps/div.

20. Adjust the oscilloscope horizontal positioning to place the rising edge of the

signal so that it crosses the second vertical and center horizontal graticule lines.

21. Use the oscilloscope measurement capability to display rise time. Rise time is determined from the 10% and 90% amplitude points on the waveform. Record the rise time for ÷1 as t

s+p.

22. Calculate the probe rise time using the following formula:

23. Record the calculated probe rise time for ÷1 on the test record.

24. Set th

e probe attenuation to ÷10.

25. Press Autoset on the oscilloscope.

26. Adjust the oscilloscope vertical sensitivity to 5 mV/div.

27. Adjust the oscilloscope vertical positioning to center the signal on screen.

28. Adjust the oscilloscope horizontal sensitivity to 500 ps/div.

29. Adjust the oscilloscope horizontal positioning to place the rising edge of the

signal so that it crosses the second vertical and center horizontal graticule lines.

30. Use the oscilloscope measurement capability to display rise time. Rise time is determined from the 10% and 90% amplitude points on the waveform. Record the rise time for ÷10 as t

s+p.

31. Calculate the probe rise time using the following formula:

32. Record the calculated probe rise time for ÷10 on the test record.

P6248 1.7 GHz Differential Probe Service Manual 13

Performance Veriﬁcation

Common-Mode R

Preparation

ejection Ratio

The following steps prepare the network analyzer for measuring common-mode rejection ratio. The actual settings may vary with different models of network analyzer. Re for details on performing these steps.

NOTE. See the appendix for an alternative procedure for testing CMRR without a

network analyzer.

The 1103 power supply can operate two probes. To keep the probe warmed up, move it to channel 2 of the 1103 while normalizing channel 1.

1. Set the network analyzer to measure transmission loss, S to both ports.

2. Set the display format to log magnitude, 1 dB/div, reference value 0 dBm, and linear frequency.

3. Set the start frequency to ≈1MHzandstopfrequencyto≈2GHz.

fer to the user documentation supplied with the network analyzer

. Attach cables

4. Set the test port power to 0 dBm.

5. Atta

6. Att

7. No

ch the cable from port 1 to the 1103 channel 1 input connector (TekProbe

connector). Use a male BNC adapter, if necessary.

ach the cable from port 2 to the 1103 channel 1 output connector

(conventional BNC). Use a male BNC adapter, if necessary.

rmalize the network analyzer to remove the loss through channel 1 of

the 1103 power supply.

14 P6248 1.7 GHz Differential Probe Service Manual

Performance Veriﬁcation

Veriﬁcation

1. Disconnect the

NOTE. Do not remove the end connected to the network analyzer. Connect the

cable to the BNC-to-Probe Tip adapter.

2. Move the p ro

3. The setup should now appear as shown. (See Figure 8.)

port 1 cable from the 1103 channel 1 input connector.

be from the 1103 channel 2 to channel 1 input connector.

Figure 8: Setup for CMRR test

NOTE. CMRR performance is inﬂuenced by cable dress. When making CMRR

measurements, keep the probe cable away from ground planes and objects. Do not allow kinks, loops or other deformities in the probe cable, and maintain a

imum distance between the probe head and the probe control box.

max

P6248 1.7 GHz Differential Probe Service Manual 15

Performance Veriﬁcation

4. Set the referen

ce value of the network analyzer to 0 dBm.

5. Connect the probe input to the CM pins on the BNC-to-probe-tip adapter. Polarity is un

important.

6. Set the probe for ÷1 attenuation.

7. Position the 0 dBm reference near the top of the screen.

8. The network analyzer plot is common-mode feedthrough, the reciprocal of

common-mode rejection ratio. CMRR can be read by inverting the sign of the magnitude, (that is, - 46 dBm common-mode feedthrough equals + 46 dBm CMRR).

9. Measure the feedthrough magnitude at 1 MHz, 100 MHz, 500 MHz, and 1GHz. Ana

lyzers with marker capability can do this directly by setting the marker intercepts at 1, 100, 500, and 1 GHz. If necessary, turn on the network analyzer Average mode with 16 averages to stabilize the reading.

10. Verify that the feedthrough is less than the values in the ÷1 Measured Feedthrough column of the table. (See Table 6.)

Table 6: CMRR and Measured Feedthrough limits

÷10

Frequency ÷1 CMRR ÷10 CMRR ÷1 Measured

1MHz ≥60 dB ≥45 dB ≤-60 dBm ≤-65 dBm

100 MHz ≥38 dB ≥25 dB ≤-38 dBm ≤-45 dBm

500 MHz ≥35 dB ≥20 dB ≤-35 dBm ≤-40 dBm

1GHz

≥30 dB ≥18 dB ≤-30 dBm ≤-38 dBm

Measured

11. Cha

nge the probe attenuation to ÷10.

12. Measure the feedthrough magnitude at 1 MHz, 100 MHz, 500 MHz, and

Hz. Analyzers with marker capability can do this directly by setting the

1G marker intercepts at 1 MHz, 100 MHz, 500 MHz, and 1 GHz.

ctual CMRR can be calculated by subtracting 20 dB from the absolute

13.A

magnitudes to compensate for the attenuation. (that is,| - 68 dB| - 20 dB = 48 dB). The calculation has been performed in the ÷10 Measured Feedthrough column.

14. Verify that the feedthrough is less than the values in ÷10 Measured Feedthrough column of the table. (See Table 6.)

16 P6248 1.7 GHz Differential Probe Service Manual

Performance Veriﬁcation

TEKPROBE Comm

unication (Operational C heck)

This step veriﬁes correct operation of the TEKPROBE interface communication with compatible oscilloscopes. It requires a TDS500, TDS600, or TDS700 series oscilloscop

1. Turn on the oscilloscope. Wait for the power on self test to complete.

2. Disconnect all cables or probes from the inputs.

3. Press the Autoset button.

4. Press the CH 1 button.

5. Use the Vertical Scale knob to set the vertical scale factor to 100 mV/div.

6. Press th

7. Select the Coupling menu (left button along lower bezel).

8. If necessary, set the input impedance to 1 MΩ (bottom button along right

side of bezel).

9. Watch the input impedance setting while attaching the probe to the CH 1.

10. Verify that the input impedance changed to 50 Ω.

11. Set the probe attenuation to ÷10.

e Vertical Menu button.

12. Verify that the channel 1 scale factor is 1 V/div.

13. Set t

14. Verify that the channel 1 scale factor is 100 mV/div.

This completes the functional check and the performance veriﬁcation.

he probe attenuation to ÷1.

P6248 1.7 GHz Differential Probe Service Manual 17

Performance Veriﬁcation

Table 7:

Probe Model/Serial Number: Certiﬁcate Number:

Temperature: RH %:

Date of Calibr

Performance t

Output offse (20°Cto30°C)

÷10 setting

÷1 setting

DC attenuation accuracy

÷10 settin

÷1 setting

Differential signal range

÷10 setting

Attenuat

Attenuation with connections reversed

÷1 setting

Attenua

Attenuation with connections reversed

Rise tim

÷1 setting

÷10 setting

Measured feedthrough

ﬁes CMRR speciﬁcations)

(veri

÷1 setting

1MHz

100 MH

500 MHz

1GHz

÷10 s

1MHz

100 MHz

500

1GHz

ation: Technician:

est

t voltage

ion

tion

etting

MHz

Minimum Incoming Outgoing Maximum

-10 mV

<265 ps

-60 dB

-38 dB

-35 d

-30 dB

-65 d

-45 dB

-40 dB

-38

9.8

0.98

9.5

0.95

_____________

_________

_____________

________

_____________

_______

_____________

____

_____________

____

_____________

___

____

_____

______

_________

__________

_____________

_________

_____________

________

_____________

_______

_____________

____

_____________

____

_____________

___

____

_____

______

_________

__________

+10 mV

10.2

1.02

10.5

1.05

N/A

18 P6248 1.7 GHz Differential Probe Service Manual

Adjustment Procedures

These procedures are for use by qualiﬁed service personnel only.

Prepare the probe for adjustment as follows:

Equipm

ent Required

1. Remove the fo

ur screws attaching the top cover from the control box.

2. Remove the top cover.

3. Attach the probe to the 1103 TEKPROBE power supply.

4. If necessary, set the line selector to the correct voltage.

5. Turn on the 1103 power supply.

6. Set the 1103 power supply offset to off (button not illuminated).

7. Allow at l

east 20 minutes for the equipment to warm up.

NOTE. Ambient temperature must be within 20 °C to 30 °C (68 ºF to 86 °F) when

you adjust the probe.

In addition to the equipment required to perform the performance veriﬁcation, the adjustment procedures require the equipment listed below. (See Table 8.)

e 8: Test equipment

Tabl

ription

Desc

Digitizing oscilloscope

quired for adjustment

(Re procedure only)

ction generator

Fun

(Square and sine wave output)

50 Ω terminator

eeded only if oscilloscope

(n does not support 50 Ω termination)

mum requirements

Mini

Bandwidth ≥100 MHz,

rage acquisition mode,

ave vertical sensitivity 2 m V /div

Output level adjustable to 10 V

, Separate Trigger

pk-pk

Sync output

50 Ω ±1Ω

ple product

Exam

tronix TDS300 series

Tek

Tektronix CFG280

Tektronix part number 011-0049-01

P6248 1.7 GHz Differential Probe Service Manual 19

Adjustment Procedures

Adjustment locations

The location of the adjustments inside the control box are shown below.

Figure 9: Adjustment locations

20 P6248 1.7 GHz Differential Probe Service Manual

Adjustment Procedures

Offset (preli

minary)

NOTE. Do not attempt to adjust offset directly on an oscilloscope equipped with

TekProbe Interface. These oscilloscopes utilize a closed loop compensation system for gain and offset, which will interfere with the manual adjustment of the probe.

1. Connect the probe as shown. (See Figure 10.)

Figure 10: Setup for the offset adjustment

2. Set the DMM to DC volts, 200 mV or 300 m V range, average on, average 10 readings.

3. Set the probe to ÷1 attenuation.

4. Adjust the ÷1 offset adjustment for 0 mV, ±1 mV.

5. Change the probe attenuation to ÷10.

6. Adjust the ÷10 offset adjustment for 0 mV, ±1 mV.

7. Keep the output cable set up for the next step.

P6248 1.7 GHz Differential Probe Service Manual 21

Adjustment Procedures

Gain

1. Set up the equipment as shown. (See Figure 11.)

a. Remove the BNC to probe tip adapter from the probe input. Insert the

Y-lead adapter into the probe tip.

b. With square pins, connect the red lead to the power supply positive

terminal, and the black lead to the power supply negat

c. Connect a ground lead from the probe case ground to the negative terminal

of the power supply.

d. Connect a second DMM to a pair of banana leads from the power supply

outputs.

ive terminal.

Figure 11: Setup for gain adjustment

2. Set the DMM monitoring the output to DC Volts, 2 or 3 volt range.

3. Set the DMM monitoring the input to the 2 or 3 volt range. Keep averaging

turned on.

4. Set the probe to ÷1 attenuation.

5. Adjust the power supply to output about 700 mV.

6. Adjust the ÷1 gain adjustment until the output voltage measures the same

as the input within ±5 mV.

22 P6248 1.7 GHz Differential Probe Service Manual

Adjustment Procedures

Offset (Final)

7. Change the prob

8. Change the DMM monitoring the input to the 20 or 30 volt range.

9. Adjust the power supply to output approximately 7 V.

10. Adjust the ÷10 gain adjustment until the DMM measuring the output reads

1/10 of the same voltage as the DMM monitoring the input within ±5 mV.

11. Keep the probe output connections for the next step.

NOTE. The

1. Repeat steps 1 through 6 of the Offset (preliminary) procedure.

2. Remove the output cable termination and input for the next procedure.

offset and gain adjustments interact.

e attenuation to ÷10.

P6248 1.7 GHz Differential Probe Service Manual 23

Adjustment Procedures

DC CMRR

1. Set up the equipment as shown. (See Figure 12.)

a. Connect a BNC cable from the output of the 1103 to the Channel 1 input

of the oscilloscope. If the oscilloscope does not have 50 Ω input setting, add a 50 Ω in-line BNC terminator at the oscilloscope input.

b. Connect the Y-lead adapter to the probe input.

c. Using square pins, connect both leads to the red binding post of a binding

post to BNC adapter.

d. Connect the BNC adapter to the function generator output. (If necessary,

use a BNC cable and a female-to-female BNC connector between the BNC adapter and the generator.) If the function generator reference (shield lead from the probe case to the black binding post.

NOTE. Do not use the BNC to probe tip adapter for this connection. The power

level of the generator will exceed the terminator rating.

of the BNC connector) is isolated from ground, connect the ground

2. Connect a second BNC cable from the function generator Trigger or Sync Output to the External Trigger or Channel 2 input of the oscilloscope.

Figure 12: Setup for DC CMRR and AC CMRR adjustments

3. Set the probe to ÷1 attenuation.

24 P6248 1.7 GHz Differential Probe Service Manual

Adjustment Procedures

4. Set the functio approximately 10 V

5. Set the oscill

n generator to square wave, 1 ms period (1 kHz frequency),

,(5Vpk).

pk-pk

oscope to display channel 1. Set channel 1 to DC and 50 Ω input impedance (or use external terminator), 2 mV/div. Set the time/division to 200 μs/div. Set the trigger source to external (or Channel 2). Set the acquisition mode to average 8 to 10 acquisitions. Apply vertical bandwidth limiting, if available, to reduce noise.

6. Adjust the trigger level for a stable trigger. (If the trigger is obtained through channel 2, it may be necessary to change the volts/div setting.)

7. The displayed square wave is the common mode feedthrough. If the probe is severely misadjusted the waveform may be off-screen. If necessary, increase the channel 1 volts/div to keep the waveform on screen.

8. Adjust the ÷1 DC CMRR for minimum amplitude in the ﬂat portions of the displayed waveform. This adjustment does not affect the leading edge

tions. Increase the vertical sensitivity as the amplitude decreases.

transi

9. Change the probe to ÷10 attenuation.

10. Adjust the ÷10 DC CMRR for minimum amplitude in the ﬂat portions of

the displayed waveform. This adjustment does not affect the leading edge

itions.

trans

11. Keep the connections for the next procedure.

P6248 1.7 GHz Differential Probe Service Manual 25

Adjustment Procedures

AC CMRR

1. Change the function generator to sine wave.

2. Set the frequency of the function generator to 5 MHz and the output amplitude

to approximately 10 V pk-pk, (5 V peak).

3. Set the probe to ÷1 attenuation.

4. Change the oscilloscope horizontal 100ns/div. If necessary, adjust the channel

2 volts/div and trigger level for a stable trigger.

5. The displayed sine wave is the common mode feedthrough. If the probe is severely misadjusted, the waveform may be off screen.

6. Adjust the ÷1 AC CMRR for minimum amplitude. Usually it is not possible to completely eliminate the high frequency feedthrough.

7. Change the probe to ÷10 attenuation.

8. Adjust the ÷10 AC CMRR for minimum amplitude.

9. There i

Repeat the DC CMRR adjustment steps 5 through 12.

10. Remov control box and the four retaining screws.

This

s some interaction between the DC and AC CMRR adjustments.

e all connections from the probe. Carefully replace the top cover of the

completes the adjustment procedures.

26 P6248 1.7 GHz Differential Probe Service Manual

Maintenance

The procedures in this section describe how to maintain and repair the P6248 differential probe.

Cleaning

Remove dirt with a soft cloth dampened in a mild detergent and water solution or isopropyl alcohol.

CAUTION. To avoid damaging the probe, use only a mild detergent and water

solution o Do not immerse the probe.

Replacing TEKPROBE Interface Pins

1. To remove the interface pin, grasp the pin with a pair of needle-nose pliers

2. To replace the pin, insert the new pin into the socket and press it in against a

r isopropyl alcohol; do not use any other solvents or abrasive cleaners.

and gently pull the pin out. (See Figure 13.)

hard surface.

Figure 13: Replacing TEKPROBE interface pins

P6248 1.7 GHz Differential Probe Service Manual 27

Maintenance

Removing and R

eplacing the TEKPROBE Interface Collar

1. To remove the collar, ﬁrmly pull the collar off by hand.

2. To replace the collar, align the smaller group of pins with the smaller of the

two holes in the interface collar and align the tabs with the slots. Gently press the two pieces together. (See Figure 14.)

Figure 14: Replacing the TEKPROBE collar

28 P6248 1.7 GHz Differential Probe Service Manual

Options

Option 95 is a report of the calibration data. This option must be ordered at the time of purchase.

P6248 1.7 GHz Differential Probe Service Manual 29

Options

30 P6248 1.7 GHz Differential Probe Service Manual

Replaceable Parts

Figure 15: P6248 replaceable parts

Table 9: P6248 Probe replaceable parts list

Fig. & index number

15-1 010-6248-00 1

-2 211-0001-00 8

-3 131-3627-02 1

-4 205-0191-01 1

Tek tronix part number

Serial no. effective

Serial no. discont’d Qty Name & description

PROBE,DIFF,ACT:1.7GHZ DIFFERENTIAL,CERTIFICATE OF TRACEABLE CALIBRATION STANDARD,P6248

SCREW,MACHINE:2-56 X 0.25,PNH,STL CD PL,POZ

CONTACT,ELEC:GOLD PLATED TIP

SHELL,ELEC CONN:BNC,ABS,DOVE GRAY

P6248 1.7 GHz Differential Probe Service Manual 31

Replaceable Parts

e 16: P6248 standard accessories

Figur

32 P6248 1.7 GHz Differential Probe Service Manual

Replaceable Parts

Table 10: Stand

Fig. & index number

16-1 020-2702-02 1

-2 196-3434-00 2 Y LEAD ADAPTER

-3 196-3504-XX 1

-4 196-3505-00 1

-5

-6 016-1781-00 1

-7

-8 016-1891-00 1

-9 016-1315-00 1

-10 206-05

-11 016-1

ard accessories

Serial Tek tronix part number

196-3437-XX 2

016-1780-00 1

69-XX

952-00

0566-XX

071-

0573-XX

071-

no.

effective

Serial no. discont’d Qty Name & descrip

tion

ACCESSORY PK

SOLDER-DOWN LEAD, 1 INCH

SOLDER-DOWN LEAD, 3 INCH

GROUND LEAD

ACCESSORY KIT: TIP SAVER, PKG OF 2

ADAPTER: LONGHORN VIA, PKG OF 2

ACCESSORY KIT: PROBE TIP ADAPTER, STRAIGHT, 8 EACH 131

MARKER FIVE COLORS

TIP, PROBE: MICROCKT TEST, 0.05 CTR

CASE, CARRYING: PROBE CARRYING CASE, P6248

MANUAL,TECH:INSTRUCTION,P6248

MANUAL,TECH:SERVICE,P6248

-7143-00

KIT, ID: CABLE MARKER BAND, 2 EACH OF

G, P6248 (Includes items 2 through 10)

P6248 1.7 GHz Differential Probe Service Manual 33

Replaceable Parts

Figure 17: P6248 optional accessories

34 P6248 1.7 GHz Differential Probe Service Manual

Replaceable Parts

Table 11 : Optio

Fig. & index number

17-1 016-1783-00 1

-2 016-1782-0

-3 016-1786-00 1

-4 016-1890-00 1

-5

-6 679-409

-7

-8 003-06

-9 011-0049-01 1

-10 1103 1

-11 012-0076-00 1

-12 679

nal accessories

4-00

Serial no. effective

Serial no. discont’d Qty Name & descrip

Tektron ix part number

016-1785-00 1

SMK4

75-00

-5027-00

tion

ACCESSORY KI 131-6247-00

ACCESSORY KIT: SPRING LOADED GROUND PINS, PKG OF 6 131-6271-00

TIP, PROBE: PKG OF FOUR 013-0305-00

ACCESSORY KIT:PROBE TIP ADAPTER,VARITIP, 8 EACH 131-7142

ADAPTER: 013-0306-00

CKT BD SUBASSY:PROBE TIP TO BNC ADAPTER

TIP,PROBE:MICROCKT TEST,PKG OF 4

ADJUSTMENT TOOL: 5 INCH TOTAL, PLASTIC,W/PLASTIC TIP ONE END METAL TIP OP P OSIT E END

TERMN,COAXIAL:50 OHM,2W,BNC

1103 TEKPROBE POWER SUPPLY

CA ASSY,RF:COAXIAL,RFD,50 OHM,20 L,BNC,

,STR,BOTH ENDS,W/STRAIN RELIEF BOOT BOTH

MALE ENDS

CKT BD SUBASSY:1394 ADAPTER

T: GROUND CONTACTS, PKG OF 10

-00

DIFFERENTIAL PRO BE,PKG OF FOUR

P6248 1.7 GHz Differential Probe Service Manual 35

Replaceable Parts

36 P6248 1.7 GHz Differential Probe Service Manual

Appendix A: Alternate Veriﬁcation Procedures

This appendix contains alternate procedures for verifying the common mode rejection ratio speciﬁcations.

Use these alternate procedures only if it is not feasible to obtain a network analyzer.

For the complete set of performance veriﬁcation procedures, refer to the Performance Veriﬁcation section and refer to this section when directed to do so.

Equipment R equired

Table 8 lists the equipment required to perform the procedures in this section. The types and you use.

Table 12: Test equipment

Description Minimum requirements Example product

Sine wave generator (preferably a synthesizer)

Spectrum analyzer 1 MHz to 1.8 GHz (dynamic

TEKP

BNCadapters (2)

BNC cables (2) 50 Ω,18inch

BNC-to-probe tip adapter

quantities of connectors may vary depending on the speciﬁc equipment

Fluke 6

Advantest R3365A

Tektronix part number 103-

Tek 012-0076-00

Tek 679-4094-00

ROBE Power Supply

to-Type-N coax

0 dBm to 20 dBm from 1MHzto1.5GHz.

≥100 dBm at 1 MHz)

range

Tektronix Type 1103 Tektronix Type 1103

N-male-to-BNC female

Type

066

0045-00

tronix part number

P6248 1.7 GHz Differential Probe Service Manual 37

Appendix A: Alternate Veriﬁcation Procedures

Preparation

Allow all test equipment to warm up for 20 minutes in an environment that is

within the environmental conditions speciﬁed. (See Table 1 on page 1.) Prepare

the equipment as follows:

1. Connect the probe tip adapter to the inputs of the probe. (For a description of these accessories, refer to the list of standard accessories).

2. Attach the probe to the 1103 TEKPROBE power supply.

3. If nec essary, set the line selector of the 1103 power supply to the correct

voltage.

4. Turn on the 1103 power supply.

5. Set the 1103 offset to off (button not illuminated).

6. Allow at least 20 minutes for the probe and equipment to warm up.

Perform the veriﬁcation procedures in order.

CMRR (Common-Mode Rejection Ratio)

1. Normalize the setup as follows:

a. Connect the equipment as shown. (See Figure 18.)

Figure 18: Normalizing the setup

b. Setthesynthesizerto1MHzand10dBm.

c. Adjust the spectrum analyzer input attenuator to accep

of 10 dBm.

d. Set the reference level to 10 dBm, the center frequency to 1 MHz, and the

vertical scale to 10 dB/div.

38 P6248 1.7 GHz Differential Probe Service Manual

t the high level

Appendix A: Alternate Veriﬁcation Procedures

e. Adjust the span

f. Record the level displayed on the spectrum analyzer.

2. Remove the BNC cable from the 1103 input, and insert the adapter and probe

as shown. (See Figure 19 on page 39.) Use the CM pins of the BNC to probe tip adapter.

NOTE. CMRR performance is inﬂuenced by cable dress. When making CMRR

measurements, keep the probe cable away from ground planes and objects. Do not allow kinks, loops or other deformities in the probe cable, and maintain a maximum distance between the probe head and the probe control box.

to 10 kHz and the resolution bandwidth to auto.

Figure 19: Setup for the CMRR tests

3. Set the probe to ÷1 attenuation.

4. Change the spectrum analyzer reference level to -20 dBm.

5. Record the level displayed on the spectrum analyzer (be sure to factor in the

change in reference level, 30 dBm). It may be necessary to use the video ﬁlter to lower the noise ﬂoor. Verify that the change in the level (relative to the level recorded in step 1 f above) is less than or equal to the ÷1 measured feed through column of the table. (See Table 13 on page 41.)

P6248 1.7 GHz Differential Probe Service Manual 39

Appendix A: Alternate Veriﬁcation Procedures

6. Set the probe to

7. Record the level displayed on the spectrum analyzer. Verify that the change

in the level (r equal to the ÷10 measured feed through column of the table. (See Table 1 3 on page 41.) (These values are 20 dB lower than the speciﬁcation to account for the ÷10 attenuation.)

8. Set the synthesizer to 100 MHz and 0 dBm.

9. Set the reference level to 0 dBm, the center frequency to 100 MHz and the

vertical scale to 10 dB/div. Adjust the span to 200 kHz and the resolution bandwidth to auto.

10. Connect the BNC cable from the synthesizer output to the 1103 input as shown. (See Figure 18 on page 38.)

11. Record the level displayed on the spectrum analyzer.

12. Remove the BNC cable from the 1103 input and insert the adapter and probe

as shown. (See Figure 19 on page 39.) Use the CM pins of the BNC to probe tip adapter.

13. Set the probe to ÷1 attenuation.

14. Record the level displayed on t he spectrum analyzer. Verify that the change in

the level (relative to the level recorded in step 11) is less than or equal to the ÷1 measured feedthrough column of the table. (See Table 13 on page 41.)

÷10 attenuation.

elative to the level recorded in step 1 f above) is less than or

15. Set the probe to ÷10 attenuation.

16. Record the level displayed on t he spectrum analyzer. Verify that the change in

the level (relative to the level recorded in step 11) is less than or equal to the ÷10 measured feedthrough column of the table. (See Table 13 on page 41.)

17. Set the synthesizer to 500 MHz and 0 dBm.

18. Set the spectrum analyzer center frequency to 500 MHz.

epeat steps 10 through 16.

19.R

20. Set the synthesizer to 1 GHz and 0 dBm.

21. Set the spectrum analyzer center frequency to 1 GHz.

NOTE. Carefully dress the probe cable so that it does not cross itself or pass near

the BNC to probe tip adapter. Improperly dressing the probe cable can affect the measurements at 1 GHz and above.

22. Repeat steps 10 through 16.

40 P6248 1.7 GHz Differential Probe Service Manual

Appendix A: Alternate Veriﬁcation Procedures

Table 13: CMRR a

Frequency ÷1 CMRR ÷10 CMRR

1MHz ≥60 dB ≥45 dB ≤-60 dBm ≤-65 dBm

100 MHz ≥38 dB ≥25 dB ≤-38 dBm ≤-45 dBm

500 MHz ≥35 dB ≥20 dB ≤-35 dBm ≤-40 dBm

1GHz

nd measured feedthrough limits

÷1 measured feedthrough

≥30 dB ≥18 dB ≤-30 dBm ≤-38 dBm

÷10 measured feedthrough

P6248 1.7 GHz Differential Probe Service Manual 41

Tektronix P6248 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual