Aeroflex 8800 Series User manual

EXPORT CONTROL WARNING: This document contains controlled technical data under the
jurisdiction of the Export Administration Regulations (EAR), 15 CFR 730-774. It cannot be
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by fine, imprisonment, or both.
Digital Radio
Test System
8800 / 8800S
Maintenance Manual

MAINTENANCE MANUAL
DIGITAL RADIO TEST SYSTEM
8800 / 8800S
PUBLISHED BY
Aeroflex
COPYRIGHT Aeroflex 2015
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or
transmitted in any form or by any means, electronic, mechanical, photocopying, recording or
otherwise without the prior permission of the publisher.
Original Printing May 2015
10200 West York / Wichita, Kansas 67215 U.S.A. / [phone] / FAX [phone]
Subject to Export Control, see Cover Page for details.

Electromagnetic Compatibility:
For continued EMC compliance, all external cables must be shielded and three meters or less in
length.
Nomenclature Statement:
In this manual, 8800 / 8800S, Test Set or Unit refers to the 8800 / 8800S Digital Radio Test System.
Subject to Export Control, see Cover Page for details.

THIS PAGE INTENTIONALLY LEFT BLANK.
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SAFETY FIRST: TO ALL SERVICE PERSONNEL
REFER ALL SERVICING OF UNIT TO QUALIFIED TECHNICAL PERSONNEL.
WARNING: USING THIS EQUIPMENT IN A MANNER NOT SPECIFIED BY THE ACCOMPANYING
DOCUMENTATION MAY IMPAIR THE SAFETY PROTECTION PROVIDED BY THE EQUIPMENT.
CASE, COVER OR PANEL REMOVAL
Opening the Case Assembly exposes the operator to electrical hazards that can result in electrical shock or
equipment damage. Do not operate this Test Set with the Case Assembly open.
SAFETY IDENTIFICATION IN TECHNICAL MANUAL
This manual uses the following terms to draw attention to possible safety hazards that may exist when
operating this equipment.
CAUTION: THIS TERM IDENTIFIES CONDITIONS OR ACTIVITIES THAT, IF IGNORED, CAN RESULT IN
EQUIPMENT OR PROPERTY DAMAGE (E.G., FIRE).
WARNING: THIS TERM IDENTIFIES CONDITIONS OR ACTIVITIES THAT, IF IGNORED, CAN RESULT IN
PERSONAL INJURY OR DEATH.
SAFETY SYMBOLS IN MANUALS AND ON UNITS
CAUTION: Refer to accompanying documents. (This symbol refers to specific CAUTIONS
represented on the unit and clarified in the text.)
AC OR DC TERMINAL: Terminal that may supply or be supplied with AC or DC voltage.
DC TERMINAL: Terminal that may supply or be supplied with DC voltage.
AC TERMINAL: Terminal that may supply or be supplied with AC or alternating voltage.
EQUIPMENT GROUNDING PRECAUTION
Improper grounding of equipment can result in electrical shock.
USE OF PROBES
Check specifications for the maximum voltage, current and power ratings of any connector on the Test Set
before connecting it with a probe from a terminal device. Be sure the terminal device performs within these
specifications before using it for measurement, to prevent electrical shock or damage to the equipment.
POWER CORDS
Power cords must not be frayed, broken nor expose bare wiring when operating this equipment.
USE RECOMMENDED FUSES ONLY
Use only fuses specifically recommended for the equipment at the specified current and voltage ratings.
INTENDED USE
The 8800 / 8800S is intended for indoor use only and should not be subjected to conditions which cause water
or other liquids to collect on the Touch Screen Display.
Subject to Export Control, see Cover Page for details.

SAFETY FIRST: TO ALL SERVICE PERSONNEL (cont)
INTERNAL BATTERY
The 8800 / 8800S contains a Lithium Ion Battery, serviceable only by a qualified technician.
WARNING: THE 8800 / 8800S USES A LITHIUM ION BATTERY PACK. THE FOLLOWING WARNINGS
CONCERNING LITHIUM ION BATTERIES MUST BE HEEDED:
•ONLY RECHARGE THE BATTERY OUTSIDE THE UNIT WITH THE EXTERNAL BATTERY
CHARGER.
•DO NOT CRUSH, INCINERATE OR DISPOSE OF IN NORMAL WASTE.
•DO NOT SHORT CIRCUIT OR FORCE DISCHARGE AS THIS MIGHT CAUSE THE BATTERY TO
VENT, OVERHEAT OR EXPLODE.
CAUTION: INTEGRATED CIRCUITS AND SOLID STATE DEVICES SUCH AS MOS FETS, ESPECIALLY CMOS
TYPES, ARE SUSCEPTIBLE TO DAMAGE BY ELECTROSTATIC DISCHARGES RECEIVED FROM
IMPROPER HANDLING, THE USE OF UNGROUNDED TOOLS AND IMPROPER STORAGE AND
PACKAGING. ANY MAINTENANCE TO THIS UNIT MUST BE PERFORMED WITH THE FOLLOWING
PRECAUTIONS:
•BEFORE USE IN A CIRCUIT, KEEP ALL LEADS SHORTED TOGETHER EITHER BY THE USE
OF VENDOR-SUPPLIED SHORTING SPRINGS OR BY INSERTING LEADS INTO A
CONDUCTIVE MATERIAL.
•WHEN REMOVING DEVICES FROM THEIR CONTAINERS, GROUND THE HAND BEING USED
WITH A CONDUCTIVE WRISTBAND.
•TIPS OF SOLDERING IRONS AND/OR ANY TOOLS USED MUST BE GROUNDED.
•DEVICES MUST NEVER BE INSERTED INTO NOR REMOVED FROM CIRCUITS WITH POWER
ON.
•PC BOARDS, WHEN TAKEN OUT OF THE SET, MUST BE LAID ON A GROUNDED
CONDUCTIVE MAT OR STORED IN A CONDUCTIVE STORAGE BAG. REMOVE ANY BUILT-IN
POWER SOURCE, SUCH AS A BATTERY, BEFORE LAYING PC BOARDS ON A CONDUCTIVE
MAT OR STORING IN A CONDUCTIVE BAG.
•PC BOARDS, IF BEING SHIPPED TO THE FACTORY FOR REPAIR, MUST BE PACKAGED IN A
CONDUCTIVE BAG AND PLACED IN A WELL-CUSHIONED SHIPPING CONTAINER.
CAUTION
THIS EQUIPMENT CONTAINS PARTS
SENSITIVE TO DAMAGE
BY ELECTROSTATIC DISCHARGE (ESD)
CAUTION: SIGNAL GENERATORS CAN BE A SOURCE OF ELECTROMAGNETIC INTERFERENCE (EMI) TO
COMMUNICATION RECEIVERS. SOME TRANSMITTED SIGNALS CAN CAUSE DISRUPTION AND
INTERFERENCE TO COMMUNICATION SERVICES OUT TO A DISTANCE OF SEVERAL MILES.
USERS OF THIS EQUIPMENT SHOULD SCRUTINIZE ANY OPERATION THAT RESULTS IN
RADIATION OF A SIGNAL (DIRECTLY OR INDIRECTLY) AND ENSURE COMPLIANCE WITH
INSTRUCTIONS IN FAA CIRCULAR AC 170-6C, DATED FEBRUARY 19, 1981.
Subject to Export Control, see Cover Page for details.

PREFACE
SCOPE
This Manual contains instructions for maintaining the 8800 / 8800S. It is strongly recommended that
the technician be thoroughly familiar with this manual before attempting to perform maintenance on
the equipment.
ORGANIZATION
The Manual is composed of the following Chapters:
CHAPTER 1 - INTRODUCTION
Provides an Introduction and Functional Descriptions for each assembly in the 8800.
CHAPTER 2 - MAINTENANCE INSTRUCTIONS
Identifies and explains Routine Service, Troubleshooting, Calibration/Verification,
Remove/Replace and Shipping/Storage Procedures.
Subject to ITAR, see Cover Page for details. i

TABLE OF CONTENTS
PARAGRAPH PAGE
CHAPTER 1 - INTRODUCTION
1-1 General Information .................................................................................. 1-1
1-1A Scope ................................................................................................. 1-1
1-1B Nomenclature Cross-Reference List........................................................ 1-1
1-2 Equipment Description .............................................................................. 1-1
1-2A Equipment Characteristics, Capabilities and Features .............................. 1-1
1-2B Equipment Data.................................................................................... 1-1
1-2C Safety, Care and Handling..................................................................... 1-1
1-3 Principles of Operation.............................................................................. 1-2
1-3-1 General Description.............................................................................. 1-2
1-3-2 Detailed Description ............................................................................. 1-3
1-3-2A RF Attenuator Assy (1A1).................................................................. 1-3
1-3-2B RF Assy (1A2).................................................................................. 1-3
1-3-2C Power Supply PCB Assy (1A3) ........................................................... 1-9
1-3-2D Multi-Function PCB Assy (1A4A1) ...................................................... 1-9
1-3-2E Display............................................................................................ 1-9
1-3-2F Arrow Control PCB Assy (1A4A5) ....................................................... 1-9
1-3-2G DMM Assy (1A4A7)........................................................................... 1-10
1-3-2H Audio I/O PCB Assy (1A4A6) ............................................................. 1-12
CHAPTER 2- MAINTENANCE INSTRUCTIONS
2-1 Service Upon Receipt................................................................................ 2-1
2-1-1 Service Upon Receipt of Materiel ........................................................... 2-1
2-1-1A Unpacking ....................................................................................... 2-1
2-1-1B Checking Unpacked Equipment .......................................................... 2-2
2-1-2 Preliminary Servicing and Adjustment of Equipment ................................. 2-2
2-2 Troubleshooting ....................................................................................... 2-3
2-2-1 Troubleshooting Guidelines ................................................................... 2-3
2-2-2 Equipment Inspection............................................................................ 2-3
2-2-3 Troubleshooting Precautions.................................................................. 2-4
2-2-4 EMC / Safety Compliance ...................................................................... 2-4
2-2-5 Battery Precautions .............................................................................. 2-5
2-2-6 Support Equipment ............................................................................... 2-5
2-2-7 Troubleshooting Tests........................................................................... 2-8
2-2-7A Unit Power-Up Failure....................................................................... 2-8
2-2-7B Arrow Control Inoperable................................................................... 2-12
2-2-7C Audio I/O and Oscilloscope Inoperable ............................................... 2-14
2-2-7D No Display....................................................................................... 2-15
2-2-7E USB Connector Failure...................................................................... 2-16
2-2-7F Touch Screen Failure........................................................................ 2-17
2-2-7G DMM Failure .................................................................................... 2-18
2-2-7H Speaker Failure................................................................................ 2-20
2-2-7I RF Power Failure / Generator and Receiver OK ................................... 2-21
2-2-7J RF Receiver Failure.......................................................................... 2-22
2-2-7K RF Generator Failure........................................................................ 2-24
2-3 Calibration / Verification Procedures........................................................... 2-27
2-3-1 Calibration / Verification Schedule ......................................................... 2-27
2-3-2 Testing Conditions................................................................................ 2-27
2-3-3 Support Equipment ............................................................................... 2-28
2-3-4 Verification Procedures......................................................................... 2-29
2-3-4A Generator Verification....................................................................... 2-29
2-3-4B Receiver RSSI Verification ................................................................ 2-32
2-3-4C TCXO Verification............................................................................. 2-38
2-3-4D RF Power Meter Verification .............................................................. 2-39
2-3-4E SWR Meter Verification..................................................................... 2-46
2-3-4F Audio Level Meter Verification ........................................................... 2-49
2-3-4G Verification Data Sheets ................................................................... 2-52
ii Subject to Export Control, see Cover Page for details.

PARAGRAPH PAGE
CHAPTER 2- MAINTENANCE INSTRUCTIONS (cont)
2-3-5 Calibration Procedures.......................................................................... 2-57
2-3-5A Calibration Setup ............................................................................. 2-57
2-3-5B TXCO Calibration ............................................................................. 2-60
2-3-5C Generator Calibration ....................................................................... 2-63
2-3-5D Receiver Calibration ......................................................................... 2-70
2-3-5E SWR Phase Detector Calibration........................................................ 2-76
2-3-5F Receiver Pre-Normalize Calibration.................................................... 2-79
2-3-5G RF Power Meter Calibration............................................................... 2-81
2-3-5H Audio Level Meter Calibration............................................................ 2-87
2-4 Remove/Replace Procedures ..................................................................... 2-89
2-4A Battery............................................................................................ 2-91
2-4B Fuse ............................................................................................... 2-93
2-4C Feet................................................................................................ 2-95
2-4D Open Case Assy............................................................................... 2-97
2-4E Power Supply PCB Assy (1A3)........................................................... 2-102
2-4F RF Attenuator Assy (1A1).................................................................. 2-104
2-4G RF Assy (1A2).................................................................................. 2-106
2-4H Multi-Function PCB Assy (1A4A1) ...................................................... 2-108
2-4I LED Display Assy (1A4A2) ................................................................ 2-111
2-4J Touch Screen Controller Assy (1A4A4) ............................................... 2-115
2-4K DMM Assy (1A4A7)........................................................................... 2-116
2-4L Audio I/O PCB Assy (1A4A6) ............................................................. 2-118
2-4M Touch Screen Assy (1A4A3) .............................................................. 2-120
2-4N Arrow Control PCB Assy (1A4A5) ....................................................... 2-124
2-4O Bird Power Meter (1A5) (Option) ........................................................ 2-128
2-5 Preparation for Storage or Shipment........................................................... 2-134
2-5A Packaging............................................................................................ 2-134
2-5B Environment......................................................................................... 2-134
APPENDICES
A Replacement Parts.................................................................................... A-1
B Connector Pin-Out Tables.......................................................................... B-1
C Support Equipment Requirements............................................................... C-1
D Abbreviations........................................................................................... D-1
E Assembly Drawings................................................................................... E-1
Subject to Export Control, see Cover Page for details. iii

LIST OF ILLUSTRATIONS / TABLES
LIST OF ILLUSTRATIONS
TITLE PAGE
System Block Diagram ................................................................................................... 1-2
RF Assy Block Diagram.................................................................................................. 1-5
Power Supply PCB Assy Block Diagram ........................................................................... 1-7
Multi-Function PCB Assy Block Diagram .......................................................................... 1-8
DMM Assy Block Diagram............................................................................................... 1-11
Audio I/O PCB Assy Block Diagram ................................................................................. 1-13
8800 / 8800S ................................................................................................................ A-13
Front Chassis Assy / Front Panel Assy ............................................................................ A-18
Power Splitter............................................................................................................... C-3
SWR Stack ................................................................................................................... C-4
8800 / 8800S ................................................................................................................ E-3
RF Attenuator Assy ....................................................................................................... E-10
RF Assy ....................................................................................................................... E-11
Power Supply PCB Assy................................................................................................. E-12
Front Chassis Assy / Front Panel Assy ............................................................................ E-13
Multi-Function PCB Assy................................................................................................ E-19
LED Display Assy.......................................................................................................... E-23
Touch Screen Assy........................................................................................................ E-24
Touch Screen Controller Assy......................................................................................... E-25
Arrow Control PCB Assy................................................................................................. E-26
Audio I/O PCB Assy....................................................................................................... E-27
DMM Assy .................................................................................................................... E-29
LIST OF TABLES
TITLE PAGE
I/O Connectors (Front Panel).......................................................................................... B-1
I/O Connectors (Rear Panel)........................................................................................... B-2
MIC Connector Pin-Out Table ......................................................................................... B-3
REMOTE Connector Pin-Out Table .................................................................................. B-4
ETHERNET Connector Pin-Out Table............................................................................... B-5
USB Connector Pin-Out Table......................................................................................... B-6
Test Equipment............................................................................................................. C-1
Adapters, Cables and Accessories .................................................................................. C-1
Power Splitter............................................................................................................... C-2
SWR Stack ................................................................................................................... C-3
iv Subject to Export Control, see Cover Page for details.

CHAPTER 1 - INTRODUCTION
1-1. GENERAL INFORMATION
A. Scope
Type of Manual: Maintenance Manual
Equipment Name and Model Number: 8800 / 8800S Digital Radio Test System
Purpose of Equipment: The 8800 / 8800S Digital Radio Test System is used for
testing radios and related equipment.
B. Nomenclature Cross-Reference List
COMMON NAME OFFICIAL NOMENCLATURE
8800 / 8800S 8800 / 8800S Digital Radio Test System
Test Set or Unit 8800 / 8800S Digital Radio Test System
1-2. EQUIPMENT DESCRIPTION
A. Equipment Characteristics, Capabilities and Features
Refer to the 8800 / 8800S Operation Manual for this information.
B. Equipment Data
Refer to the 8800 / 8800S Operation Manual for this information.
C. Safety, Care and Handling
Observe all WARNINGS, CAUTIONS and NOTES in this manual. This equipment can be extremely
dangerous if these instructions are not followed.
CAUTION
THIS EQUIPMENT CONTAINS PARTS
SENSITIVE TO DAMAGE
BY ELECTROSTATIC DISCHARGE (ESD)
Subject to Export Control, see Cover Page for details. 1-1

1-3. PRINCIPLES OF OPERATION
1-3-1 GENERAL DESCRIPTION
POWER
SUPPLY
BATTERY
DMM
MULTI-
FUNCTION
MIC
SCOPE
AUDIO IN
AUDIO OUT
ETHERNET
POWER
METER
RESISTIVE
CONTROLLER
TOUCH SCREEN
CONTROL
ARROWS
AUDIOI/O
HEADPHONES
USB
DC IN
REMOTE
RF
ATTENUATOR
RF
OUT
IN
ANT
GEN
T/R
COM
AMP
V/OHM
LED DISPLAY
Figure 1-1. System Block Diagram
1-2 Subject to Export Control, see Cover Page for details.

1-3-2 DETAILED DESCRIPTION
The System Block Diagram (Figure 1-1) and the System Interconnect Diagram (Figure E-1) shows the
relationship of all assemblies. The following paragraphs are detailed descriptions of the 8800 /
8800S assemblies.
A. RF Attenuator Assy (1A1)
The RF Attenuator Assy consists of 20 dB Attenuator and temperature alarm circuitry. The 20 dB
Attenuator supplies 50 Ωimpedance for the T/R Connector to insure VSWR is <1.2:1. The
temperature alarm circuit triggers a warning when the temperature of the pad is >90°C.
The RF Attenuator Assy allows the 8800 / 8800S to receive 50 W of continuous RF CW signals.
B. RF Assy (1A2) (Figure 1-2)
The RF Assy consists of the RF Converter PCB Assy and the RF Controller PCB Assy. The RF Assy
receives power and control via the Multi-Function PCB Assy.
The RF Converter PCB Assy contains the RF termination for the T/R Connector, ANT Connector and
GEN Connector, as well as the frequency translation circuitry and step attenuator for both the receive
and generate paths. The RF Controller PCB Assy interfaces directly with the Multi-Function PCB
Assy to control the RF Assy. The RF Controller PCB Assy contains the 80 MHz TCXO system clock
and the RF synthesizers that generate the required Local Oscillator (LO) signals.
An 80 MHz TCXO with a stability of 1 ppm provides the reference signal for the RF Assy as well as
the Multi-Function PCB Assy. The 80 MHz TCXO provides the reference signal to the five Phase
Lock Loops (PLL) used to generate the required Local Oscillator (LO) signals.
The Generate path of the RF Assy receives a 10.5 MHz IF signal from the Multi-Function PCB Assy.
This signal is mixed with the 80 MHz Gen. 3rd LO to create a 69.5 MHz IF that is filtered to remove
unwanted mixing products and amplified before being input to the Generate leveler circuit. The
Generate leveler circuit is used to set the desired output signal level by compensating for variations
in flatness over the 2 to 1000 MHz output band. The 69.5 MHz IF is then mixed with the 1330 MHz
Generate 2nd LO to produce a 1399.5 MHz IF. The output of the mixer is filtered to remove unwanted
mixing products and amplified before being input to the last mixer. The Generate 1st LO, which
covers 1401.5 to 2399.5 MHz, is mixed with the 1399.5 MHz IF to produce an output frequency of 2 to
1000 MHz. Following the mixer the signal passes through a low-pass filter and into an amplifier. The
output of the amplifier is tapped off to the Generate Level detector. The output of the detector is
feed back to the Generate Leveler to level the generate system. The RF signal out of the amplifier
then passes through the step attenuators. The step attenuators provide 60 dB of attenuation in 1 dB
steps to set the signal level out of the Unit. The signal is then input to a RF switch. One port of the
switch goes to the T/R Connector via a 3 dB pad, 3 way resistive splitter. This allows the T/R
Connector to accept signal levels up to 125 W directly into the Test Set.
The other port of the RF switch is input to a second RF switch which steers the signal to either the
ANT Connector or the SWR circuit. When the ANT Connector is selected, the signal passes through
another RF switch to insure sufficient isolation and is coupled to the ANT Connector through the ANT
Connector protection relay.
Connected to the ANT and GEN Connectors are the connector protection circuits. These circuits are
designed to protect the rest of the circuitry from damage if a high power signal is inadvertently input
to either of these connectors. If the signal level input to either connector is too high, the signal level
is detected by diode detector and the mechanical relay at the connector is opened. Additionally a
signal is sent to the software via the Multi-Function PCB Assy that alerts the operator that an
overload condition exists.
Subject to Export Control, see Cover Page for details. 1-3

B. RF Assy (1A2) (Figure 1-2) (cont)
The GEN Connector can be used to measure SWR and Distance to Fault (DTF) or as a generate
connector providing up to -5 dBm output. When SWR or DTF testing is selected, the signal is
amplified and passes through a 6 dB pad to insure a good match at the GEN Connector. The signal
then goes through two directional couplers and the GEN connector protection relay. The coupler
couples off the forward and reverse power at the GEN Connector. The coupled signals are input to a
dual Log Amp that outputs video signal proportional to the amplitude and phase difference of the
forward and reverse power. From these measurements the software can calculate the SWR of the
UUT. It is necessary to calibrate the SWR circuitry by connecting a short, an open and a 50 Ω
termination to the end of the cable connected to the UUT.
When the 8800 / 8800S is in a Receive Mode, either Transmitter Test or Duplex Test, the signal may
be input to the T/R or ANT Connector.
The resistive splitter feeds part of the received signal to the power detect circuit. The power detect
circuit is a diode detector used to measure the input power for the Power Meter function. The
resistive splitter also feeds the signal through a 10 dB pad to the receive connector selection switch.
When the ANT Connector is selected, a signal input to the ANT Connector passes through the
protection circuitry to the receive connector selection switch. From this point on both the ANT and
T/R Connectors share a common path. The signal is input to the step attenuator that provides 0 to
30 dB of attenuation in 10 dB steps. Following the attenuator part of the signal is tapped of to feed
the log amp detector. The detected level out of the log amp is used to insure that the receiver does
not go into compression.
The received signal passes through a low-pass filter to remove out-of-band signal to the switchable
pre-amp. The pre-amp is selected by software to increase sensitivity for low-level signals. The
signal is then input to a mixer where the signal is mixed with the Receive 1st LO. The LO is tunable
from 1405 to 2403 MHz to produce an IF signal at 1403 MHz. The IF signal is filtered to remove
unwanted mixing products and amplified before being input to a second mixer. The signal is then
mixed with the Receive 2nd LO of 1310 MHz to down-convert the signal to a 93 MHz IF. The 93 MHz
IF is amplified and filtered then input to the 3rd mixer. The signal is mixed with the Receive 3rd LO
of 80 MHz to down-convert the signal to the final IF of 13 MHz. The IF then passes through a low-
pass filter and an amplifier before being input to a switchable filter network. At this point the signal
either passes through a 1 MHz wide bandpass filter or a 3 dB pad that compensates for the insertion
loss of the filter. Following the switchable filter, the signal then passes through several selectable
gain amplifiers before being output to the Multi-Function PCB Assy for digital processing. The
amplifiers are selectable in gain increments of 10 dB and controlled by the AGC software.
1-4 Subject to Export Control, see Cover Page for details.

Figure 1-2. RF Assy Block Diagram (Sheet 1 of 2)
(RF Controller PCB Assy)
Subject to Export Control, see Cover Page for details. 1-5

Figure 1-2. RF Assy Block Diagram (Sheet 2 of 2)
(RF Converter PCB Assy)
Subject to Export Control, see Cover Page for details. 1-6

Figure 1-3. Power Supply PCB Assy
Block Diagram
Subject to Export Control, see Cover Page for details. 1-7

Figure 1-4. Multi-Function PCB Assy
Block Diagram
Subject to Export Control, see Cover Page for details. 1-8

C. Power Supply PCB Assy (1A3) (Figure 1-3)
The Power Supply PCB Assy is responsible for supplying power to the internal modules for operation
and for charging the internal batteries. The Power Supply PCB Assy operates from externally
supplied DC power and provides simultaneous run and battery charge, or battery charge only. The
battery charge time increases when in the run and charge mode. The Power Supply PCB Assy
consists of a DC-DC Converter, ON/OFF Control circuitry and the Battery Charger circuitry. The
external DC input is supplied from an External DC Power Supply (supplied).
The internal batteries are removable/replaceable Li Ion battery packs with an internal "gas-gauge"
feature that allows accurate determination of remaining battery life. Maximum operating and storage
temperature for Li Ion batteries is -20°C to +60°C and the maximum charging temperature is 0°C to
+45°C.
The Power Supply PCB Assy contains a synchronous buck converter to convert the input voltage to a
fixed output voltage (+10 Vdc). The Power Supply PCB Assy also contains a low-pass filter to reduce
the amount of internal emissions. The Input Converter Assembly is capable of providing enough
output current to charge the battery and run the Test Set at the same time, as long as the input
voltage is within range.
D. Multi-Function PCB Assy (1A4A1) (Figure 1-4)
The Multi-Function PCB Assy provides processor control of various digital, analog and RF sub-
circuits used to generate or receive RF signaling normally used in mobile radio communication. The
Multi-Function PCB Assy also contains the application specific circuits to control the other
assemblies.
The user interface consists of the LCD Panel and Touch Screen, along with the Power, Menu and
Arrow Buttons. The ETHERNET, USB and REMOTE Connectors provide digital connectivity to the
external devices.
E. Display
The Display feature of the 8800 / 8800S consists of a LED Backlight Assy, Touch Screen Assy and
Touch Screen Controller Assy. The Touch Screen is the User Interface. The Multi-Function PCB
Assy receives and sends signals and data from the external connectors to the LCD. The Touch
Screen Controller Assy interacts with the user interface portion of the Multi-Function PCB Assy to
control menu interaction and backlight capability.
On the Touch Screen Assy, the touchpad sensor is composed of two resistive layers separated by an
air gap. One plate is used for the X axis and the other plate is used for the Y axis. When pressure
is applied the two resistive plates make contact. A microcontroller measures position and pressure
then uses advanced algorithms to yield smooth mouse functionality. When not touched, the touchpad
appears to the microcontroller as an open switch.
F. Arrow Control PCB Assy (1A4A5
The Arrow Control PCB Assy consists of five pushbutton switches to navigate up, down, left and right
or to enter a value in a displayed field.
Subject to Export Control, see Cover Page for details. 1-9

G. DMM Assy (1A4A7) (Figure 1-5)
The Digital Multimeter is a self-contained, electrically isolated, digital module capable of operating at
temperatures of -20°C to +70°C. The Digital Multimeter measures AC and DC voltage, current and
resistance within ±5% full scale of the selected range. The Digital Multimeter measures up to
400 VAC or Vdc, 3 A of current and 40 MW of resistance.
The Digital Multimeter is designed around a self-contained, Integrated Circuit (IC) that is controlled
by an on-board host microprocessor (uP). The Digital Multimeter’s uP is responsible for transferring
digitized measurement data from the Digital Multimeter IC to the 8800 / 8800S, for processing all
commands sent to the Digital Multimeter module from the 8800 / 8800S and for retaining calibration
values for each function and range on the Digital Multimeter’s flash memory.
The host processor performs the auto-ranging function using a resistive voltage divider network with
various branches that are switched in or out by the Digital Multimeter IC according to the overflow
data.
The Digital Multimeter contains AC compensation capacitors that flatten out the AC voltage response
of the meter over the range of 0 to ~ 20 kHz. The precision values of the AC compensation
capacitors are critical to the proper operation of the AC voltage function over the entire frequency
bandwidth.
The internal voltages for the Digital Multimeter module are received from a +5 V input from the Test
Set via an isolated 5 V DC to DC Converter whose output is also 5 Vdc and post regulated via a
linear regulator IC. The output from the DC to DC Converter is split into separate +2.5 and -2.5 V
supplies for the associated analog circuitry.
The Digital Multimeter +5 V input supply and the 2-wire serial data port circuits that run between the
Test Set and Digital Multimeter module are both electrically isolated within the Digital Multimeter
module to prevent damage and personal injury which may occur when inappropriately high voltages
are applied to the input terminals.
The AC Voltage function of the Digital Multimeter module is a true RMS reading achieved by using an
RMS voltage converter IC. When AC Voltage measurements are being performed, the voltage is
automatically routed through the RMS converter IC, then back into the Digital Multimeter IC for
conversion. Streaming results and measurement data are then passed to the Test Set via the internal
uP over a 2-wire serial link.
The AC and DC Current metering capability of the Digital Multimeter module is protected from
overload by a fuse located on the front of the module. The fuse is rated at 3 A maximum for a period
of 10 seconds. The voltage and resistance input terminals are internally protected from the
application of excessive voltages by a gas discharge tube across the inputs.
1-10 Subject to Export Control, see Cover Page for details.