HP 83447A Manual

User and Service Guide
HP 83447A Lightwave
Trigger Receiver

HP part number: 83447-90002
Edition 1 Printed in USA April 1996
1400 Fountaingrove Parkway,
Santa Rosa, CA
95403-1799, USA
Notice. The information contained in this document is subject to change
without notice. Hewlett-Packard makes no warranty of any kind with regard
to this material, including but not limited to, the implied warranties of
merchantability and tness for a particular purpose
. Hewlett-Packard shall
not be liable for errors contained herein or for incidental or consequential
damages in connection with the furnishing, performance, or use of this
material.
Restricted Rights Legend. Use, duplication, or disclosure by the U.S.
Government is subject to restrictions as set forth in subparagraph (c) (1) (ii)
of the Rights in Technical Data and Computer Software clause at DFARS
252.227-7013 for DOD agencies, and subparagraphs (c) (1) and (c) (2) of the
Commercial Computer Software Restricted Rights clause at FAR 52.227-19 for
other agencies.
c
 Copyright Hewlett-Packard Company 1996
All Rights Reserved. Reproduction, adaptation, or translation without prior
written permission is prohibited, except as allowed under the copyright laws.

Printing History
HP Part Number Edition Date
83447-90002 Edition 1 April 1996
iii

Safety Symbols
The following safety symbols are used throughout this manual. Familiarize
yourself with each of the symbols and its meaning before operating this
instrument.
CAUTION
The caution sign denotes a hazard to the instrument. It calls attention to a
procedure which, if not correctly performed or adhered to, could result in
damage to or destruction of the instrument. Do not proceed beyond a caution
sign until the indicated conditions are fully understood and met.
WARNING
The warning sign denotes a life-threatening hazard. It calls attention to a
procedure which, if not correctly performed or adhered to
, could result
in injury or loss of life. Do not proceed beyond a warning sign until the
indicated conditions are fully understood and met.
L The instruction manual symbol. The product is marked with this symbol when it is
necessary for the user to refer to the instructions in the manual.
A This symbol denotes that the instrument uses alternating current.
j This symbol denotes that the power supply is turned on.
 This symbol denotes that the power supply is turned o.
CE The CE mark is a registered trademark of the European Community
.
ISM1-A This symbol denotes that the instrument is an Industrial Scientic and Medical Group 1 Class
A product.
The CSA mark is a registered trademark of the Canadian Standards Association.
iv

General Safety Considerations
WARNI NG
This is a Safety Class I product (provided with a protective earthing
ground incorporated in the power cord). The mains plug shall only be
inserted in a socket outlet provided with a protective earth contact.
Any interruption of the protective conductor inside or outside of the
instrument is likely to make the instrument dangerous. Intentional
interruption is prohibited.
WARNI NG
Before this instrument is switched on , make sure it has been properly
grounded through the protective conductor of the ac power cable to a
socket outlet provided with protective earth contact. Any interruption
of the protective (grounding) conductor, inside or outside the instrument,
or disconnection of the protective earth terminal can result in personal
injury.
WARNI NG
Light energy connected to the instrument's OPTICAL IN connector
radiates from the instrument's OPTICAL OUT connector. It is only slightly
attenuated.
WARNI NG
If this instrument is not used as specied, the protection provided by the
equipment could be impaired. This instrument must be used in a normal
condition (in which all means for protection are intact) only
.
WARNI NG
There are many points in the instrument which can, if contacted, cause
personal injury. Be extremely careful. Any adjustments or service
procedures that require operation of the instrument with protective
covers removed should be performed only by trained service personnel.
WARNI NG
No operator serviceable parts inside. Refer servicing to qualied
personnel. To prevent electrical shock, do not remove covers
.
WARNI NG
For continued protection against re hazard, replace line fuse only with
same type and ratings. The use of other fuses or materials is prohibited.
CAUTI ON
Always use the three-prong AC power cord supplied with this instrument.
Failure to ensure adequate earth grounding by not using this cord may cause
instrument damage.
v

CAUTION
This product has autoranging line voltage input. Be sure the supply voltage is
within the specied range.
vi

Certication and Assistance
Hewlett-Packard Company certies that this product met its published
specications at the time of shipment from the factory. Hewlett-Packard
further certies that its calibration measurements are traceable to the United
States National Institute of Standards and Technology (NIST), to the extent
allowed by the Institute's calibration facility, and to the calibration facilities of
other International Standards Organization members.
Product maintenance agreements and other customer assistance agreements
are available for Hewlett-Packard products.
For any assistance, contact your nearest Hewlett-Packard Sales and Service
Oce.
vii

Warranty
This Hewlett-Packard instrument product is warranted against defects in
material and workmanship for a period of one year from date of shipment.
During the warranty period, Hewlett-Packard Company will, at its option,
either repair or replace products which prove to be defective.
For warranty service or repair, this product must be returned to a service
facility designated by Hewlett-Packard. Buyer shall prepay shipping charges
to Hewlett-Packard and Hewlett-Packard shall pay shipping charges to return
the product to Buyer. However, Buyer shall pay all shipping charges
, duties,
and taxes for products returned to Hewlett-Packard from another country.
Hewlett-Packard warrants that its software and rmware designated by
Hewlett-Packard for use with an instrument will execute its programming
instructions when properly installed on that instrument. Hewlett-Packard
does not warrant that the operation of the instrument, or software
,or
rmware will be uninterrupted or error-free.
Limitation of Warranty
The foregoing warranty shall not apply to defects resulting from improper
or inadequate maintenance by Buyer, Buyer-supplied software or
interfacing, unauthorized modication or misuse, operation outside of the
environmental specications for the product, or improper site preparation
or maintenance.
NO OTHER WARRANTY IS EXPRESSED OR IMPLIED. HEWLETT-PACKARD
SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
Exclusive Remedies
THE REMEDIES PROVIDED HEREIN ARE BUYER'S SOLE AND EXCLUSIVE
REMEDIES. HEWLETT-PACKARD SHALL NOT BE LIABLE FOR ANY
DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
DAMAGES, WHETHER BASED ON CONTRACT, TORT, OR ANY OTHER
LEGAL THEORY.
viii

In This Book
Chapter 1 provides general information, specications and
characteristics, and electrostatic discharge information for
the lightwave trigger receiver.
Chapter 2 describes how to install the lightwave trigger receiver,
connect to a high-speed optical oscilloscope, perform a quick
condence check, return the instrument for service, and
how to clean connections.
Chapter 3 describes how to perform a waveform test.
Chapter 4 describes troubleshooting, adjustment, performance tests,
and replacement procedures.
ix

Contents
1. General Information
Description of the HP 83447A . . . . . . . . . . . . . 1-3
Front-panel features . . . . . . . . . . . . . . . . 1-6
HP 83447A Specications and Characteristics . . . . . . 1-8
Declaration of Conformity . . . . . . . . . . . . . . 1-11
Electrostatic Discharge Information . . . . . . . . . . 1-12
Reducing ESD damage . . . . . . . . . . . . . . . 1-14
2. Installation and Preparation for Use
Installing the HP 83447A . . . . . . . . . . . . . . . 2-3
Step 1. Inspect the shipment . . . . . . . . . . . . 2-3
Step 2. Set the line voltage selector . . . . . . . . . 2-4
Step 3. Check the fuse . . . . . . . . . . . . . . . 2-5
Step 4. Connect the HP 83447A to a po
wer source . . 2-6
Step 5. Turn on the HP 83447A . . . . . . . . . . . 2-9
Connecting the HP 83447A to a Digital Communications
Analyzer . . . . . . . . . . . . . . . . . . . . 2-10
Performing a Quick Condence Check . . . . . . . . . 2-12
If the verication check fails . . . . . . . . . . . . 2-12
How to Return the HP 83447A for Service . . . . . . . 2-14
Packaging . . . . . . . . . . . . . . . . . . . . 2-14
Instrument shipping preparation pro cedure . . . . . . 2-15
Sales and service oces . . . . . . . . . . . . . . 2-16
Cleaning Connections for Accurate Measurements . . . . 2-19
To clean a non-lensed connector . . . . . . . . . . . 2-21
To clean an adapter . . . . . . . . . . . . . . . . 2-22
3. Using the HP 83447A
Waveform Test . . . . . . . . . . . . . . . . . . . 3-3
Triggering on data versus triggering on clo ck . . . . . 3-3
Contents-1

Replaceable parts
4. Servicing the HP 83447A
General Information . . . . . . . . . . . . . . . . . 4-3
Troublesho oting . . . . . . . . . . . . . . . . . . . 4-5
Adjustment Pro cedures . . . . . . . . . . . . . . . 4-9
Power supply adjustment pro cedure . . . . . . . . . 4-9
Photo detector assembly adjustment pro cedure . . . . 4-11
Performance Tests .... .. .. .. .. .. .. .. . 4-12
Test 1. Through-path optical insertion loss . . . . . . 4-13
Test 2. Trigger output amplitude . . . . . . . . . . 4-15
Test 3. Trigger output RMS jitter . . . . . . . . . . 4-23
Test 4. Trigger port electrical return loss . . . . . . . 4-26
Test 5. Input optical return loss . . . . . . . . . . . 4-29
Replacement Procedures . . . . . . . . . . . . . . . 4-31
Replacing the RF cable or the RF connector . . . . . 4-32
Replacing the ac cable assembly . . . . . . . . . . . 4-33
Replacing the power supply . . . . . . . . . . . . . 4-35
Replacing the photo detector assembly . . . . . . . . 4-36
Replaceable parts . . . . . . . . . . . . . . . . . . 4-37
Index
Contents-2

Figures
1-1. HP 83447A block diagram. . . . . . . . . . . . . . . . . 1-4
1-2. The HP 83447A front panel. .... .. .. .. .. .. . 1-6
1-3. Example of a static-safe work station. ........... 1-13
2-1. Opening the fuse holder door. .............. 2-4
2-2. Selecting the line voltage value and checking the fuse. ... 2-5
2-3. AC power cables available. ................ 2-8
2-4. Connecting the HP 83447A to a digital communications
analyzer. ...................... 2-10
3-1. Setup for measuring eye diagram by triggering from recovered
trigger. ....................... 3-4
4-1. HP 83447A block diagram. . . . . . . . . . . . . . . . . 4-5
4-2. Through-path optical insertion loss test setup. ....... 4-13
4-3. Laser transmitter setup. .. .. .. .. .. .. .. .. . 4-15
4-4. General test setup. .. .. .. .. .. .. .. .. .. . 4-17
4-5. Electrical return loss test setup............... 4-26
4-6. Wiring diagram for the line module.... .. .. .. .. . 4-33
4-7. Wiring diagram for the power supply terminals. .. .. .. 4-35
4-8. HP 83447A assembly level replaceable parts......... 4-39
4-9. HP 83447A replaceable hardware.............. 4-41
Contents-3

Tables
1-1. HP 83447A Specications and Characteristics . . . . . . . . 1-9
1-2. Static-Safe Accessories . . . . . . . . . . . . . . . . . . 1-14
2-1. HP 83447A Power Requirements .. .. .. .. . .. .. 2-6
2-2. Hewlett-Packard Sales and Service Oces .. .. .. .. . 2-17
4-1. Required Tools ..................... 4-4
4-2. Voltages on the DC Power Supply Terminals ........ 4-8
4-3. Required Test Equipment . . . . . . . . . . . . . . . . . 4-12
4-4. Laser Transmitter Setup .. .. .. .. .. .. .. .. . 4-16
4-5. Trigger Output Amplitude Test Setup ........... 4-18
4-6. Input Optical Return Loss ................ 4-29
4-7. Torque Values . . . . . . . . . . . . . . . . . . . . . . 4-32
4-8. Line Module to DC Power Supply Connections ....... 4-34
4-9. DC Power Supply Terminal Connections .... .. .. .. 4-35
4-10. Assembly-Level Replaceable Parts . . . . . . . . . . . . . 4-40
4-11. Replaceable Hardware . . . . . . . . . . . . . . . . . . 4-42
Contents-4

1
General Information

General Information
What you'll nd in this chapter
 A brief description of the HP 83447A lightwave trigger receiver.
 A list of options and accessories available.
 HP 83447A specications and characteristics.
 Information about the lightwave receiver's serial number label.
 Information about avoiding damage to the instrument from electrostatic discharge
.
1-2

Description of the HP 83447A
The HP 83447A lightwave trigger receiver is used to generate an electrical
trigger signal from an optical waveform. A typical usage is for eye-diagram
analysis of telecommunications optical signals where an external electrical
clock signal is not available as a timing reference.
For more information on using the lightwave trigger receiver refer to
Chapter 3.
Learning the inside
story ...
The block diagram for the HP 83447A is shown in Figure 1-1. The optical
input uses 9  m single-mode ber. The optical signal to be measured is
routed to the HP 83447A. Inside the HP 83447A, the signal is passed through
an asymmetric coupler, where approximately 10% of the power is tapped.
The remaining 90% of the optical signal is sent directly out of the HP 83447A
and can be connected to the measuring instrument. The 10% signal is
detected by a high-gain avalanche photodiode (APD). The electrical signal
from the APD is amplied by an AC-coupled, two-stage limiting amplier.
The output can be used as a timing reference
, such as a trigger signal for an
instrument like the HP 83480A digital communications analyzer.
This technique is similar to \splitting" an electrical signal from an
optical-electrical (O/E) converter to trigger an oscilloscope. However, a key
advantage to using the HP 83447A technique is that the optical signal to be
measured experiences only a minor level of attenuation, typically 1 dB
o
.
Splitting an electrical signal usually results in a 6 dB
e
loss. Because the
O/E element of the HP 83447A is an APD and two stages of amplication,
a preamp and a limiting amplier, the output electrical signal exceeds
200 mV
p-p
with input optical modulation powers lower than 20  W
p-p
,
(such as a 0 20 dBm average power with a 10 dB or higher extinction ratio).
Placing an electrical splitter after an O/E converter can degrade the frequency
response of the measurement channel, resulting in inaccurate measurements
.
The HP 83447A triggering technique preserves the integrity of the electrical
signal path.
1-3

General Information
Description of the HP 83447A
Figure 1-1. HP 83447A block diagram.
Accessories supplied The HP 83447A lightwave trigger receiver is shipped with:
Power cable (refer to Figure 2-3)
FC/PC front-panel connector interfaces (deleted on option 010)
HP 83447A Lightwave Trigger Receiver User and Service Guide .
1-4

General Information
Description of the HP 83447A
Serial Numbers Hewlett-Packard makes frequent improvements to its products to enhance
their performance, usability, or reliability, and to control costs. HP service
personnel have access to complete records of design changes to each type
of equipment, based on the equipment's serial number. Whenever you
contact Hewlett-Packard about your lightwave receiver, have the complete
serial number available to ensure obtaining the most complete and accurate
information possible.
A serial-number label is attached to the rear of the lightwave receiver.
It contains the serial number and the options installed in the lightwave
receiver. Whenever you specify the serial number or refer to it in obtaining
information about your lightwave receiver, be sure to use the complete
number.
1-5

General Information
Description of the HP 83447A
Front-panel features
Figure 1-2. The HP 83447A front panel.
1. Line switch.
2. Powerline LED.
3. TRIGGER OUT connector (Type N).
4. OPTICAL OUT connector. This output accepts any of the connector
interface adapters from the HP 81000-series.
5. OPTICAL IN connector. Maximum signal input is +3 dBm and minimum
signal input is 0 20 dBm. This input accepts any of the connector interface
adapters from the HP 81000-series.
NOTE
Optical output power is typically ' 1 dB lower than the input power.
1-6