UBS Axcera HU5000BTD User Manual

Instruction Manual

Innovator HXB Series

Digital UHF

Solid State

Transmitter

Volume 2

UHF Amplifier Cabinet

Axcera , LLC

103 Freedom Drive • P.O. Box 525 • Lawrence, PA 15055-0525 USA

1-724-873-8100 • FAX: [phone]

www.axcera.com • [e-mail]

RESTRICTIONS ON USE, DUPLICATION OR DISCLOSURE

OF PROPRIETARY INFORMATION

This document contains information proprietary to Axcera, to its affiliates or to a third party to
which Axcera may have a legal obligation to protect such information from unauthorized
disclosure, use or duplication. Any disclosure, use or duplication of this document or any of the
information herein for other than the specific purpose for which it was disclosed by Axcera is
expressly prohibited, except as Axcera may otherwise agree in writing. Recipient by accepting this
document agrees to the above stated conditional use of this document and this information
disclosed herein.

Copyright © 2009, Axcera

Innovator® HXB Series, Digital, Table of Contents
UHF Transmitter

TABLE OF CONTENTS

CHAPTER 1: INTRODUCTION

SECTION PAGE

1.1: Manual Overview .................................................................................1-1

1.2: Safety.................................................................................................1-1

1.3: Assembly Designators ..........................................................................1-2

1.4: Material Return Procedure.....................................................................1-2

1.5: Limited One-Year Warranty for Axcera Products ......................................1-3

CHAPTER 2: UHF AMPLIFIER CABINET

2.1: Cabinet Overview.................................................................................2-1

2.2: Description of the UHF Amplifier Cabinet ................................................2-2

2.2.1: 5 kW Amplifier Cabinet with 8 Amplifier Assemblies........................2-3

2.2.2: 3.7 kW Amplifier Cabinet with 6 Amplifier Assemblies .....................2-3

2.2.3: 2.5 kW Amplifier Cabinet with 4 Amplifier Assemblies .....................2-3

2.2.4: 1.8 kW Amplifier Cabinet with 3 Amplifier Assemblies .....................2-4

2.3: Description of the UHF Amplifier Tray.....................................................2-7

2.3.1: Description of the 8 Way Combiner Assembly (5 kW) .....................2-7

2.3.1.1: Description of the 6 Way Combiner Assembly (3.7 kW)..........2-9

2.3.1.2: Description of the 4 Way Combiner Assembly (2.5 kW)..........2-9

2.3.1.3: Description of the 3 Way Combiner Assembly (1.8 kW)..........2-9

2.3.2: Removal of an Amplifier Tray Assembly.........................................2-9

2.3.3: Amplifier Cabinet Power Supply Assemblies ................................. 2-10

2.3.4: Control and Monitoring ..............................................................2-10

2.3.5: Cabinet Cooling ........................................................................ 2-10

2.4: Cabinet Controller Assembly................................................................ 2-12

2.4.1: Controller Connections to the Transmitter’s System Controller.......2-13

2.4.2: Controller Connections to the Amplifier Cabinet Components......... 2-14

2.4.2.1: Power Amplifiers.............................................................. 2-14

2.4.2.2: High Power Voltage Supply Controllers............................... 2-14

2.4.2.3: Low Power Voltage Supply and AC Line Monitoring.............. 2-15

2.4.2.4: Air Temperature and Amplifier Temperature Monitoring .......2-15

2.4.2.5: RF Power Monitoring ........................................................2-15

2.4.2.6: Reject Load Monitoring..................................................... 2-16

2.4.3: Cabinet Controller Settings ........................................................ 2-16

2.4.4: Cooling Blower Control .............................................................. 2-17

2.4.5: Cabinet Controller Problem Resolution Guide ............................... 2-17

2.5: Functional Description of Amplifier Cabinet ...........................................2-19

2.5.1: Signal Path...............................................................................2-19

2.5.2: Test Signal Evaluation ...............................................................2-19

2.5.3: Regulation of Transmitter Output Power...................................... 2-19

2.5.4: Fault Protection Circuitry ........................................................... 2-19

2.5.5: Capture of Operating Values in the Amplifiers .............................. 2-20

2.5.6: Amplifier Cabinet Connections.................................................... 2-20

2.6: Service ............................................................................................. 2-21

2.6.1: Safety Information.................................................................... 2-21

2.6.1.1: Labeling of Dangerous Substances ....................................2-21

2.6.2: Test point Evaluation................................................................. 2-21

2.6.3: Display of Operating Values ....................................................... 2-21

2.7: Exchange of an Amplifier Module .........................................................2-22

Volume 2, Rev. 0 i November 16, 2009

Innovator® HXB Series, Digital, Table of Contents
UHF Transmitter

TABLE OF CONTENTS (continued)

CHAPTER 3: UHF AMPLIFIER TRAY ASSEMBLY & CABINET ASSEMBLIES
CIRCUIT DESCRIPTIONS

SECTION PAGE

3.1: Amplifier Overview...............................................................................3-1

3.2: Design of the UHF Amplifier Tray ...........................................................3-2

3.2.1: Capture of Test Values in the UHF Amplifier Tray............................3-5

3.2.2: Functional Description of the Boards in the Amplifier Assembly ........3-6

3.2.2.1: Phase/Gain Board ..............................................................3-6

3.2.2.2: Dual BLF871 Amplifier Module Assembly ..............................3-6

3.2.2.3: Coupler Board ...................................................................3-6

3.2.2.4: 4 Way Splitter Board..........................................................3-7

3.2.2.5: UHF Broadband Pallet Board, BLF878...................................3-8

3.2.2.6: 4 Way Combiner Board ......................................................3-8

3.2.2.7: FET Switch/Metering Board.................................................3-9

3.2.2.7.1: Operating voltages for the Amplifier Boards................3-9

3.2.2.8: Amplifier Control Board ......................................................3-9

3.2.2.8.1: Schematic Drawing 1311684 Page 1........................3-10

3.2.2.8.2: Schematic Page 2 .................................................. 3-11

3.2.2.8.3: Schematic Page 3 .................................................. 3-11

3.2.2.8.4: Schematic Page 4 .................................................. 3-11

3.2.2.8.5: Schematic Page 5 .................................................. 3-12

3.3: Troubleshooting and Repair of the Amplifier..........................................3-12

3.3.1: Safety Information.................................................................... 3-12

3.3.2: Troubleshooting........................................................................3-12

3.3.2.1: Front Panel LEDs ............................................................. 3-12

3.3.2.2: Polling Fault Indications.................................................... 3-13

3.4: Exchanging Amplifiers ........................................................................ 3-13

3.4.1: Exchange of a Module ............................................................... 3-13

3.4.2: Mounting a New Module............................................................. 3-13

3.4.3: Final Steps...............................................................................3-13

3.4.4: External Connections to Amplifier Assembly.................................3-14

3.5: Power Supply Assembly......................................................................3-14

3.5.1: Overview of the +48V Power Supply Unit .................................... 3-15

3.5.2: Description of SCR Controllers.................................................... 3-15

3.5.3: Description of the Step Down Transformers .................................3-15

3.5.4: Description of the Linear Power Supply Assemblies....................... 3-15

3.5.4.1: Description of the Power Supply Monitoring Board...............3-16

3.6: Full Amplifier Cabinet Controller Board .................................................3-20

3.6.1: Schematic Drawing 1307524 Page 1 ........................................... 3-20

3.6.2: Schematic Drawing Page 2......................................................... 3-20

3.6.3: Schematic Drawing Page 3......................................................... 3-21

3.6.4: Schematic Drawing Page 4......................................................... 3-21

3.6.5: Schematic Drawing Page 5......................................................... 3-21

3.7: Half Amplifier Cabinet Controller Board................................................. 3-24

3.7.1: Schematic Drawing 1307841 Page 1 ........................................... 3-24

3.7.2: Schematic Drawing Page 2......................................................... 3-24

3.7.3: Schematic Drawing Page 3......................................................... 3-25

3.7.4: Schematic Drawing Page 4......................................................... 3-25

3.7.5: Schematic Drawing Page 5......................................................... 3-25

3.8: Temperature Sensor Board ................................................................. 3-26

Volume 2, Rev. 0 ii November 16, 2009

Innovator® HXB Series, Digital, Table of Contents
UHF Transmitter

TABLE OF CONTENTS (continued)

SECTION PAGE

3.9: Serial Loop-Thru Board....................................................................... 3-26

3.10: Load Regulator Assembly.................................................................. 3-26

3.10.1: Load Regulator Board..............................................................3-26

APPENDICES

APPENDIX A: RF Amplifier Cabinet Assembly, HXB Series
Drawings and Parts Lists

APPENDIX B: UHF Amplifier Tray Assembly, HXB Series
Drawings and Parts Lists

APPENDIX C: +48 VDC Power Supply Assemblies, Top and Bottom
Drawings and Parts Lists

Volume 2, Rev. 0 iii November 16, 2009

Innovator® HXB Series, Digital, Table of Contents
UHF Transmitter

LIST OF FIGURES

FIGURE PAGE

1-1 Marker Identification Drawing..........................................................1-2

2-1 Typical UHF Amplifier Cabinet (Front View) .......................................2-1

2-2 Block Diagram Typical UHF Amplifier Cabinet 8 Way (5 kW)................2-2

2-3 Block Diagram Typical UHF Amplifier Cabinet 4 Way (2.5 kW).............2-4

2-4 Components in the Amplifier Cabinet................................................2-5

2-5 Block Diagram Typical UHF Amplifier Tray Assembly ..........................2-6

2-6 Block Diagram Typical 8 Way UHF Combiner Assembly.......................2-8

2-7 Air Flow in the Amplifier Cabinet ....................................................2-11

2-8 Full Cabinet Controller Assembly.................................................... 2-12

2-9 Half Cabinet Controller Assembly ................................................... 2-12

2-10 Amplifier Cabinet Connections ....................................................... 2-20

2-11 Labeling of Toxic Substances in Drawings ....................................... 2-21

2-12 Location and Assignment of the Circuit Breakers and LEDs ...............2-22

2-13 Amplifier Tray Lock Location.......................................................... 2-23

3-1 UHF Amplifier Tray Assembly...........................................................3-1

3-2 Remaining Power after Failure of Amplifier Modules ...........................3-2

3-3 Location of the Assemblies in the UHF Amplifier.................................3-3

3-4 Block Diagram of the UHF Amplifier Tray ..........................................3-4

3-5 Interconnect Typical UHF Amplifier Tray Assembly.............................3-5

3-6 AC Wiring Harness UHF Amplifier Cabinet .......................................3-14

3-7 Interconnect Linear Power Supply #1, Top...................................... 3-17

3-8 Interconnect Linear Power Supply #2, Bottom ................................3-18

3-9 Control Interconnect Cabinet Full Controller System ........................ 3-19

3-10 Control Interconnect Cabinet Half Controller System........................ 3-23

Volume 2, Rev. 0 iv November 16, 2009

Innovator® HXB Series, Digital, Table of Contents
UHF Transmitter

LIST OF TABLES

TABLE PAGE

2-1 Serial Cable Pin Out......................................................................2-14

2-2 Cabinet Controller SW2 DIP Switch Settings....................................2-16

2-3 Cabinet Controller Assembly Problem Resolution Guide ....................2-17

2-4 Amplifier Cabinet Connections ....................................................... 2-21

3-1 Assemblies in the UHF Amplifier.......................................................3-2

3-2 Module OK LED Red and Blinking Interpretation ................................3-5

3-3 Module OK LED Red and Blinking Interpretation .............................. 3-10

3-4 Module OK LED Red and Blinking Interpretation .............................. 3-12

3-5 RF Connectors on the Front Panel .................................................. 3-14

3-6 Operating Voltage Connection (Rear Panel)..................................... 3-14

3-7 Configuration of SW2 on Full Amplifier Cabinet Control Board ........... 3-22

3-8 Configuration of SW2 on Half Amplifier Cabinet Control Board........... 3-25

Volume 2, Rev. 0 v November 16, 2009



Innovator

HXB Series Digital Chapter 1, Introduction

UHF Transmitter

Chapter 1:

Introduction

The Innovator HXB Series UHF digital
solid-state transmitter is comprised of
two cabinet types: An exciter/control
cabinet and a UHF amplifier cabinet.
Every Innovator HXB includes one or
more of each cabinet type, dependent
upon the power configuration ordered.
This volume, Volume 2, of the manual
describes the UHF amplifier cabinet
portion of the transmitter. The system
and the exciter/control assemblies are
covered in Volume 1.

1.1: Manual Overview

Volume 2, of the Innovator HXB Series
Digital UHF Transmitter Instruction
Manual, is divided into three chapters
and supporting appendices. Chapter 1,
Introduction, contains information on
safety, return procedures, and
warranties. Chapter 2, Amplifier
Cabinet, describes the UHF amplifier
cabinet. Chapter 3, UHF Amplifier Tray
Assembly and Cabinet Assemblies Circuit
Descriptions, contains a detailed
discussion of the UHF amplifier module
and power supply assemblies that are
contained in the cabinet. Appendix A
contains the RF amplifier cabinet
assembly drawings and parts lists.
Appendix B contains the UHF amplifier
Tray assembly drawings and parts lists.
Appendix C contains the top and bottom
+48VDC power supply assemblies’
drawings and parts lists.

1.2: Safety

The HXB Series UHF transmitters
manufactured by Axcera are designed to
be easy to use and repair while providing
protection from electrical and mechanical
hazards. Listed throughout the manual
are notes, cautions, and warnings
concerning possible safety hazards that
may be encountered while operating or
servicing the transmitter. It is important
that users review these warnings and
become familiar with the operation and

servicing procedures before working on
the transmitter.

Hazardous Accessibility – Axcera has
made attempts to provide appropriate
connectors, wiring and shields to
minimize hazardous accessibility.

Circuit Breakers and Wiring – All
circuit breakers and wire are UL and CE
rated and are rated for maximum
operating conditions.

Single Point Breaker or Disconnect ­The customer should provide a single
point breaker or disconnect at the
breaker box for the main AC input
connection to the transmitter.

Transmitter Ratings - The transmitter
ratings are provided in the text of this
manual along with voltage and current
values for the equipment.

Protective Earthing Terminal – A main
protective earthing terminal is provided
for equipment required to have
protective earthing.

Read All Instructions – All of the
operating and safety instructions should
be read and understood before operating
this equipment.

Retain Manuals – The manuals for the
equipment should be retained at the site
in which the equipment is operating for
future reference. We provide two sets of
manuals for this purpose; one set can be
left at the office while one set can be
kept at the site.

Heed all Notes, Warnings, and
Cautions – All of the notes, warnings,

and cautions listed in this safety section
and throughout the manual must be
followed.

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HXB Series Digital Chapter 1, Introduction

UHF Transmitter

Follow Instructions – All of the
operating and use instructions for the
product should be followed.

Cleaning – Unplug or otherwise
disconnect all power from the equipment
before cleaning. Do not use liquid or
aerosol cleaners. Use a damp cloth for
cleaning.

Ventilation – Openings in the cabinet
and module front panels are provided for
ventilation. To ensure the reliable
operation of the transmitter, and to
protect the unit from overheating, these
openings must not be blocked.

Servicing – Do not attempt to service
this product yourself until becoming
familiar with the equipment. If in doubt,
refer all servicing questions to qualified
Axcera service personnel.

Replacement Parts – When
replacement parts are needed, be sure
that the parts have the same functional
and performance characteristics as the
original part. Unauthorized substitutions
may result in fire, electric shock, or other
hazards. Please contact the Axcera
Technical Service Department if you have
any questions regarding service or
replacement parts.

1.3: Assembly Designators

Axcera has assigned assembly numbers,
Ax designations such as A1, where
x=1,2,3…etc, to all assemblies, modules,
and boards in the system. These
designations are referenced in the text of
this manual and shown on the block
diagrams and interconnect drawings
provided in the appendices. The Block
Diagrams, Interconnects, Schematics,
Assembly Drawings and Parts Lists are
arranged in increasing numerical order in
the appendices. Section titles in the text
for assembly or module descriptions or
alignment procedures contain the
associated part number(s) and the

relevant appendix that contains the
drawings for that item.

The cables that connect between the
boards within a tray or assembly and
that connect between the trays, racks
and cabinets are labeled using markers.
Figure 1 is an example of a marked
cable. There may be as few as two or
as many as four Markers on any one
cable. These markers are read starting
farthest from the connector. If there
are four Markers, the marker farthest
from the connector is the system
number such as system 1 or translator

2. The next or the farthest Marker is the
rack or cabinet “A” number on an
interconnect cable or the board “A”
number when the cable is within a tray.
The next number on an interconnect
cable is the Tray location or Board “A”
number. The marker closest to the
connector is the jack or connector “J”
number on an interconnect cable or the
jack or connector “J” number on the
board when the cable is within a tray.

4

3 2

1

Figure 1-1: Marker Identification

Drawing

1.4: Material Return Procedure

To insure the efficient handling of
equipment or components that have been
returned for repair, Axcera requests that
each returned item be accompanied by a
Return Material Authorization Number
(RMA#).

The RMA# can be obtained from any
Axcera Service Engineer by contacting
the Axcera Technical Service Department
at 1-724-873-8100 or by fax at 1-724­873-8105. This procedure applies to all
items sent to the Technical Service
Department regardless of whether the

Volume 2, Rev. 0 1-2

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Innovator

HXB Series Digital Chapter 1, Introduction

UHF Transmitter

item was originally manufactured by
Axcera.

When equipment is sent to the field on
loan, the RMA# is included with the unit.
The RMA# is intended to be used when
the unit is returned to Axcera. In
addition, all shipping material should be
retained for the return of the unit to
Axcera.

Replacement assemblies are also sent
with the RMA# to allow for the proper
routing of the exchanged hardware.
Failure to close out this type of RMA# will
normally result in the customer being
invoiced for the value of the loaner item
or the exchange assembly.

When shipping an item to Axcera, please
include the RMA# on the packing list and
on the Axcera-provided shipping
container. The packing slip should also
include contact information and a brief
description of why the unit is being
returned.

Please forward all RMA items to:

Axcera
Customer Service Department
103 Freedom Drive
P.O. Box 525
Lawrence, PA 15055-0525 USA

For more information concerning this
procedure, call the Axcera Technical
Service Department.

Service can also be contacted through e­mail at [e-mail] and on the
Web at www.axcera.com.

1.5: Limited One-Year Warranty for
Axcera Products

Axcera warrants each new product that
it has manufactured and sold against
defects in material and workmanship
under normal use and service for a
period of one (1) year from the date of
shipment from Axcera's plant, when

operated in accordance with Axcera's
operating instructions. This warranty
shall not apply to tubes, fuses,
batteries, or bulbs.

Warranties are valid only when and if
(a) Axcera receives prompt written
notice of breach within the period of
warranty, (b) the defective product is
properly packed and returned by the
buyer (transportation and insurance
prepaid), and (c) Axcera determines, in
its sole judgment, that the product is
defective and not subject to any misuse,
neglect, improper installation,
negligence, accident, or (unless
authorized in writing by Axcera) repair
or alteration.

Axcera's exclusive liability for any
personal and/or property damage
(including direct, consequential, or
incidental) caused by the breach of any
or all warranties, shall be limited to the
following: (a) repairing or replacing (in
Axcera's sole discretion) any defective
parts free of charge (F.O.B. Axcera’s
plant) and/or (b) crediting (in Axcera's
sole discretion) all or a portion of the
purchase price to the buyer.

Equipment furnished by Axcera, but not
bearing its trade name, shall bear no
warranties other than the special hours­of-use or other warranties extended by
or enforceable against the manufacturer
at the time of delivery to the buyer.

NO WARRANTIES, WHETHER
STATUTORY, EXPRESSED, OR
IMPLIED, AND NO WARRANTIES OF
MERCHANTABILITY, FITNESS FOR
ANY PARTICULAR PURPOSE, OR
FREEDOM FROM INFRINGEMENT,
OR THE LIKE, OTHER THAN AS
SPECIFIED IN PATENT LIABILITY
ARTICLES, AND IN THIS ARTICLE,
SHALL APPLY TO THE EQUIPMENT
FURNISHED HEREUNDER.

Volume 2, Rev. 0 1-3

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Innovator
UHF Transmitter

HXB Series Digital Chapter 1, Introduction



 WARNING!!!



 HIGH VOLTAGE 

DO NOT ATTEMPT TO REPAIR OR TROUBLESHOOT THIS EQUIPMENT UNLESS
YOU ARE FAMILIAR WITH ITS OPERATION AND EXPERIENCED IN
SERVICING HIGH VOLTAGE EQUIPMENT. LETHAL VOLTAGES ARE PRESENT
WHEN POWER IS APPLIED TO THIS SYSTEM. IF POSSIBLE, TURN OFF
POWER BEFORE MAKING ADJUSTMENTS TO THE SYSTEM.

 RADIO FREQUENCY RADIATION HAZARD 

MICROWAVE, RF AMPLIFIERS AND TUBES GENERATE HAZARDOUS RF
RADIATION THAT CAN CAUSE SEVERE INJURY INCLUDING CATARACTS,
WHICH CAN RESULT IN BLINDNESS. SOME CARDIAC PACEMAKERS MAY BE
AFFECTED BY THE RF ENERGY EMITTED BY RF AND MICROWAVE
AMPLIFIERS. NEVER OPERATE THE TRANSMITTER SYSTEM WITHOUT A
PROPERLY MATCHED RF ENERGY ABSORBING LOAD ATTACHED. KEEP
PERSONNEL AWAY FROM OPEN WAVEGUIDES AND ANTENNAS. NEVER
LOOK INTO AN OPEN WAVEGUIDE OR ANTENNA. MONITOR ALL PARTS OF
THE RF SYSTEM FOR RADIATION LEAKAGE AT REGULAR INTERVALS.

Volume 2, Rev. 0 1-4

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Innovator

HXB Series Digital Chapter 1, Introduction

UHF Transmitter

EMERGENCY FIRST AID INSTRUCTIONS

Personnel engaged in the installation, operation, or maintenance of this equipment are urged to become
familiar with the following rules both in theory and practice. It is the duty of all operating personnel to be
prepared to give adequate Emergency First Aid and thereby prevent avoidable loss of life.

RESCUE BREATHING

1. Find out if the person is
breathing.

You must find out if the person
has stopped breathing. If you
think he is not breathing, place
him flat on his back. Put your ear
close to his mouth and look at his
chest. If he is breathing you can
feel the air on your cheek. You
can see his chest move up and
down. If you do not feel the air
or see the chest move, he is not
breathing.

2. If he is not breathing, open
the airway by tilting his head
backwards.

Lift up his neck with one hand
and push down on his forehead
with the other. This opens the
airway. Sometimes doing this will
let the person breathe again by
himself.

SKIN REDDENED: Apply ice cold water to burned
area to prevent burn from going deeper into skin
tissue. Cover area with a clean sheet or cloth to
keep away air. Consult a physician.

SKIN BLISTERED OR FLESH CHARRED: Apply
ice cold water to burned area to prevent burn from
going deeper into skin tissue.

3. If he is still not breathing,
begin rescue breathing.

-Keep his head tilted backward.
Pinch nose shut.

-Put your mouth tightly over his
mouth.

-Blow into his mouth once every
five seconds.

-DO NOT STOP rescue breathing
until help arrives.

LOOSEN CLOTHING - KEEP
WARM

Do this when the victim is
breathing by himself or help is
available. Keep him as quiet as
possible and from becoming
chilled. Otherwise treat him for
shock.

BURNS

Cover area with clean sheet or cloth to keep away
air. Treat victim for shock and take to hospital.

EXTENSIVE BURN - SKIN BROKEN: Cover area
with clean sheet or cloth to keep away air. Treat
victim for shock and take to hospital.

Volume 2, Rev. 0 1-5



POWER SUPPLY #2

(A18) UHF AMPLIFIER #2

(A24) UHF AMPLIFIER #8

(A22) UHF AMPLIFIER #6

Innovator

HXB Series Digital Chapter 2, Amplifier Cabinet

UHF Transmitter

Chapter 2:

Amplifier Cabinet

2.1: Cabinet Overview

The fully populated amplifier cabinets
used in Innovator HXB Transmitters
contain eight UHF amplifiers connected
in parallel (Figure 2-1). The number of
amplifiers varies according to the
needed output power for the
transmitter. The amplifiers operate,
without the need for tuning or
alignment, on the UHF channel
designated.

All equipment in the cabinet is fully
solid-state and designed for high­operational reliability and a service­friendly layout. The cabinet is cooled by
external air cooling equipment. The
cooling air is ducted into and out of the
top of the cabinet.

(A17) UHF AMPLIFIER #1

(Not present in 2.5kW)

(Not present in 2.5kW)

(A21) UHF AMPLIFIER #5

POWER SUPPLY #1

CIRCUIT BREAKER

CIRCUIT BREAKER

Figure 2-1: Typical 8 Way UHF Amplifier Cabinet (Front View)

(A19) UHF AMPLIFIER #3
(Not present in 2.5kW)

(A20) UHF AMPLIFIER #4
(Not present in 2.5kW)

(A23) UHF AMPLIFIER #7

±12VDC POWER SUPPLY

RESET BREAKERS

Volume 2, Rev. 0 2-1



Innovator

HXB Series Digital Chapter 2, Amplifier Cabinet

UHF Transmitter

Figure 2-2: Block Diagram of the typical UHF Amplifier Cabinet 8 Way (5kW)

2.2: Description of the UHF Amplifier
Cabinet

The features of the amplifier cabinet
include: 1) Amplifiers that are 100%
transistors. 2) High redundancy due to
the parallel connection of power
transistors. 3) A mean junction
temperatures less than 120° C. 4)
Multiple fault protection circuitry in each
amplifier. 5) A power supply for
Amplifiers 1 thru 3 (3.7kW) and 4
(5kW). 6) A separate power supply for
Amplifiers 6 thru 8 (1.8kW) and 5
(2.5kW & 5kW). 7) Amplifiers that
operate over the selected band of UHF
frequencies without the need for
alignment. 8) The important operating
parameters are displayed in the
transmitter touch screen control unit. 9)
There are multiple test points in the
signal path. 10) It has air cooling, with

the input and output air connections on
the top of the amplifier cabinet.

The amplifier assemblies in each
amplifier cabinet (see Figure 2-3) are
slide-in units, inserted from the front.
In a 5kW cabinet, two 4 way splitters
are installed, one in the top and one in
the bottom half of the cabinet. In a 2.5
kW cabinet, just the bottom 4 way
splitter is present. These splitters
distribute the RF input to each of the
amplifiers. In a 3.7kW cabinet, 3 way
splitters are installed in the top and
bottom half of the cabinet. In a 1.8 kW
cabinet, just the bottom 3 way splitter is
present. These distribute the RF input
to each of the amplifiers. A 3, 4, 6 or 8
way combiner is installed in the middle
of the cabinet. The lower part of the
cabinet accommodates a power
distribution panel that contains two 480

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Innovator

HXB Series Digital Chapter 2, Amplifier Cabinet

UHF Transmitter

VAC 30 Amp 3 Phase or 208 VAC 50
Amp 3 Phase circuit breakers for 3.7 & 5
kW or one circuit breaker for 1.8 & 2.5
kW. The left breaker, if present,
distributes the main AC voltage to the
top power supply and the right circuit
breaker controls the bottom power
supply. The top power supply provides
the +48 VDC to the top three or four
amplifier assemblies. The bottom power
supply provides the +48 VDC to the
bottom three or four amplifier
assemblies

There is also either one or two 1 Amp
reset circuit breakers, mounted on the
power distribution panel that protect the
AC voltage to the switching power
supply, located in the bottom and top
power supply. If one breaker is present,
it connects to the bottom power supply,
for 1.8 & 2.5 kW. If 2 one Amp reset
breakers are present, the second one
amp breaker connects to the top power
supply for 3.7 & 5 kW. The switching
supply provides the ±12 VDC to the top
and bottom amplifier assemblies.

2.2.1: 5 kW Amplifier Cabinet with 8
Amplifier Assemblies

Refer to Figure 2-2. The DTV RF signal
from the exciter/control cabinet is
connected through RG-55 cable through
an opening in the roof in the UHF
amplifier cabinet. The RF (+26 dBm,
400 mW) from the output of the exciter
control cabinet connects to the SMA “S”
input on (A14) a 2 way splitter with each
of the two outputs connecting to a 4
way splitter panel (A15 top & A16
bottom). The four outputs of the (A15­A1) Top 4 way splitter are at the “N”
connectors X1-X4.

The outputs (+15.3 dBm, 34 mW)
connect to the (A17) UHF amplifier #1,
(A18) UHF amplifier #2, (A19) UHF
amplifier #3 and (A20) UHF amplifier
#4. Each amplifier tray has a gain of
approximately +40.5dB. The four
outputs of the (A16-A1) Bottom 4 way
splitter, at “N” connectors X1-X4,

connect to the (A21) UHF amplifier #5,
(A22) UHF amplifier #6, (A23) UHF
amplifier #7, and (A24) UHF amplifier
#8. The eight outputs of the amplifier
modules at 7/16” connectors (+58.3
dBm, 675W) are cabled to the (A24) 8
way combiner. The output of the
combiner connects to the (A26) RF
coupler. The output of the cabinet is
approximately (+67.2 dBm, 5.2kW) at
the 3-1/8” output connector of the (A26)
RF Coupler Assembly.

2.2.2: 3.7 kW Amplifier Cabinet with
6 Amplifier Assemblies

The DTV RF signal from the
exciter/control cabinet is connected
through RG-55 cable through an opening
in the roof in the UHF amplifier cabinet.
The RF (+27 dBm, 500 mW) from the
output of the exciter control cabinet
connects to the SMA “S” input on (A14)
a 2 way splitter with each of the two
outputs connecting to a 3 way splitter
panel (A15 top & A16 bottom). The
three outputs of the (A15) Top 3 way
splitter are at the “N” connectors X1-X3.

The outputs (+18 dBm, 63 mW) connect
to the (A17) UHF amplifier #1, (A18)
UHF amplifier #2 and (A19) UHF
amplifier #3. The three outputs of the
(A16) Bottom 3 way splitter, at “N”
connectors X2-X4, connect to the (A22)
UHF amplifier #6, (A23) UHF amplifier
#7, and (A24) UHF amplifier #8. Each
amplifier tray has a gain of
approximately +40.5dB. The six
outputs of the amplifier modules at
7/16” connectors (+58.5 dBm, 700W)
are cabled to the (A24) 6 way combiner.
The output of the combiner connects to
the (A26) RF coupler. The output of the
cabinet is approximately (+65.7 dBm,

3.7 kW) at the 3-1/8” output connector
of the (A26) RF Coupler Assembly.

2.2.3: 2.5 kW Amplifier Cabinet with
4 Amplifier Assemblies

Refer to Figure 2-3. The DTV RF signal
from the exciter/control cabinet is

Volume 2, Rev. 0 2-3

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HXB Series Digital Chapter 2, Amplifier Cabinet

UHF Transmitter

connected through RG-55 cable through
an opening in the roof in the UHF
amplifier cabinet. The RF (+26 dBm,
400 mW) from the output of the exciter
control cabinet connects to the 4 way
splitter panel (A16) mounted at the
bottom of the cabinet. The four outputs
of the (A16-A1) 4 way splitter, at “N”
connectors X1-X4, connect to the (A21)
UHF amplifier #5, (A22) UHF amplifier
#6, (A23) UHF amplifier #7, and (A24)
UHF amplifier #8. Each amplifier tray
has a gain of approximately +40.5dB.
The four outputs of the amplifier
modules at 7/16” connectors (+58.5
dBm, 700W) are cabled to the (A25) 4
way combiner assembly. The combiner
produces a single output that connects
to the (A26) RF Coupler Assembly. The
RF output for the cabinet, approximately
+64.1 dBm, 2570 Watts, is at the 3-1/8”
output connector of the RF Coupler
Assembly.

2.2.4: 1.8 kW Amplifier Cabinet with
3 Amplifier Assemblies

The DTV RF signal from the
exciter/control cabinet is connected
through RG-55 cable through an opening
in the roof in the UHF amplifier cabinet.
The RF (+27 dBm, 500 mW) from the
output of the exciter control cabinet
connects to the 3 way splitter panel
(A16) mounted at the bottom of the
cabinet. The three outputs of the (A16)
3 way splitter, at “N” connectors X2-X4,
connect to the (A22) UHF amplifier #6,
(A23) UHF amplifier #7, and (A24) UHF
amplifier #8. Each amplifier tray has a
gain of approximately +40.5dB. The
three outputs of the amplifier modules
at 7/16” connectors (+58.5 dBm, 700W)
are cabled to the (A25) 3 way combiner
assembly. The combiner produces a
single output that connects to the (A26)
RF Coupler Assembly. The RF output for
the cabinet, approximately +62.6 dBm,
1800 Watts, is at the 3-1/8” output
connector of the RF Coupler Assembly.

Figure 2-3: Block Diagram of the typical UHF Amplifier Cabinet 4 Way (2.5kW)

Volume 2, Rev. 0 2-4

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(A20) not used in 3.7kW

VDC

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HXB Series Digital Chapter 2, Amplifier Cabinet

UHF Transmitter

Components in the Amplifier Cabinet

8 UHF Amplifier Trays (5kW)
6 UHF Amplifier Tray (3.7kW)
2 Power Supply Assemblies (3.7 &
5kW)

4 UHF Amplifier Trays (2.5kW)
3 UHF Amplifier Trays (1.8kW)
1 Power Supply Assembly (1.8 &

2.5kW)

One Circuit Breaker Assembly
One 3, 4, 6 or 8 Way Combiner

Splitter 1 : 4 (5kW)
Splitter 1 : 3 (3.7kW)

UHF Amplifier Trays (A17,
A18, A19 & A20) (5kW)

Combiner 8 : 1 (5kW)
Combiner 6 : 1 (3.7kW)
Combiner 4 : 1 (2.5kW)
Combiner 3 : 1 (1.8kW)

Circuit Breaker for Top

+48VDC Power Supply (3.7kW & 5kW)

Circuit Breaker for Bottom +48

Power Supply (1.8, 2.5 3.7 & 5kW)

Figure 2-4: Components in the Amplifier Cabinet

UHF Amplifier Trays
(A21, A22, A23 & A24)
(2.5kW & 5kW)
(A21) not used in 1.8 & 2.7kW

Splitter 1 : 4 (2.5kW & 5kW)
Splitter 1 : 3 (1.8kW & 3.7kW)

Circuit Breaker for Top
12VDC Power Supply (3.7kW &
5kW) Assembly

Circuit Breaker for Bottom
12VDC Power Supply (1.8, 2.5 &
5kW) Assembly

Volume 2, Rev. 0 2-5

Figure 2-5: Block Diagram Typical UHF Amplifier Tray Assembly

HXB Series Digital Chapter 2, Amplifier Cabinet

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UHF Transmitter

Volume 2, Rev. 0 2-6

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HXB Series Digital Chapter 2, Amplifier Cabinet

UHF Transmitter

2.3: Description of the HXB UHF
Amplifier Tray
(1311943; Appendix B)

There are eight of these trays in an 8
way Amplifier Cabinet Assembly for
5kW, six in a 6 way Amplifier Cabinet
Assembly for 3.7 kW, four in a 4 way
Amplifier Cabinet Assembly for 2.5 kW,
or three in a 3 way Amplifier Cabinet
Assembly for 1.8 kW. The Amplifier
Tray has an approximate gain of +40.5
dB.

The RF input (+15 dBm ATSC) at the
“N” connector J1 on each UHF amplifier
assembly is fed to the RF input
connections on (A1) the Phase/Gain
Board (1311583), whichprovides phase
adjustment and gain control of the RF
signall. The Phase/Gain Board is also a
predriver with ≈9 dB gain. The output
(+24 dBm) is cabled to the RF input
connections on (A2) a Dual BLF871
Amplifier Pallet Assembly (1311991)
with ≈18 dB gain. The output (+42
dBm) is fed to J9 on (A12) a Coupler
Board (1311882) that supplies a driver
forward power sample out of J3-5 to the
FET switch/metering board at J1-1. The
sample is not used on the FET
switch/metering board (1312342); it is
just fed through to J15-1 that is wired to
J3-13 on the (A14) amplifier control
board (1311683) where it is used in the
amplifier protection circuitry. The output
of the coupler board at J8 (+42 dBm) is
fed to J1 on (A4) the 4 Way Splitter
Board (1306371) where it is split. Each
output of the splitter (+36 dBm) is
cabled to the RF Input jack of one of the
four (A5-A8), UHF pallet broadband
amplifier boards, BLF878 (1313170).
Each pallet board has ≈+18 dB of gain.
The outputs of each amplifier board
(+54 dBm) are combined on (A13) the 4
way broadband combiner assembly,
(1311945).

The RF output jack J2, of the 4 way
combiner assembly (+58.9 dBm), is Bus
wire jumpered to J4 on the (A12)

Coupler Board (131882) that supplies a
RF sample out at J1, that connects to
the front panel. Also, the Coupler Board
provides a final amp forward metering
sample at J3-1 and a final amp reflected
metering sample at J3-2. The samples
are connected to (A17) the FET switch/
metering board (1312342) at J1-6 and
J1-7. The samples are not used on the
FET switch/metering board, they are just
fed through to J15-2 and J15-14 that
are wired to J3-12 and J3-25 on the
amplifier control board where they are
used in the amplifier protection circuitry.
The RF output of the coupler board is at
J2 that is Bus wire connected to J2 the
7/16” connector RF Output Jack of the
amplifier assembly. Typical output level
is +58.9 dBm ATSC.

2.3.1: Description of the 8 Way
Combiner Assembly (5 kW Amplifier
Cabinet)

The RF outputs of the eight amplifiers
are combined by means of an 8:1
combiner assembly that is mounted in
the middle of the cabinet. The 8 way
combiner is made up of two identical 4
way combiners and a two way combiner.
Refer to Figure 2-6.

The outputs of the top four amplifier
trays, ≈+58.9 dBm in level, connect to
the (A1) 4 Way combiner. The outputs
of the bottom four amplifier trays,
≈+58.9 dBm in level, connect to the
(A2) 4 Way combiner. Each 4 Way
combiner has three dummy loads, two
600W and a 1200W, connected to them,
which dissipate any power due to an
imbalance or mismatch during the
combining of the amplifiers. The
outputs of the two 4 way combiners,
each ≈+64.1 dBm, connect to the (A3)
Two Way Combiner. The 2 Way
combiner has a 2500W load connected
to it. The output of the 2 Way
Combiner, which is the output of the 8
Way Combiner Assembly, is at the 3
1/8” RF output jack, typically ≈+67
dBm.

Volume 2, Rev. 0 2-7

Figure 2-6: Block Diagram Typical 8 Way UHF Combiner Assembly

HXB Series Digital Chapter 2, Amplifier Cabinet

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UHF Transmitter

Volume 2, Rev. 0 2-8

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HXB Series Digital Chapter 2, Amplifier Cabinet

UHF Transmitter

2.3.1.1: Description of the 6 Way
Combiner Assembly (3.7 kW
Amplifier Cabinet)

The RF outputs of the six amplifiers are
combined by means of an 6:1 combiner
assembly that is mounted in the middle
of the cabinet. The 6 way combiner is
made up of two identical 3 way
combiners and a two way combiner.

The outputs of the top thee amplifier
trays, ≈+58.9 dBm in level, connect to
the (A1) 3 Way combiner. The outputs
of the bottom three amplifier trays,
≈+58.9 dBm in level, connect to the
(A2) 3 Way combiner. Each 3 Way
combiner has two 600W dummy loads,
which dissipate any power due to an
imbalance or mismatch during the
combining of the amplifiers. The
outputs of the 3 way combiners, each
+64.1 dBm, connect to the (A5) Two
Way Combiner. The 2 Way combiner
has a 2500W load connected to it. The
output of the 2 Way Combiner, which is
the output of the 6 Way Combiner
Assembly is at the 3 1/8” RF output
jack, typically ≈+65.7 dBm.

2.3.1.2: Description of the 4 Way
Combiner Assembly (2.5 kW
Amplifier Cabinet)

The RF outputs of the four amplifiers are
combined by means of a 4:1 combiner
assembly that is mounted in the middle
of the cabinet.

The four RF inputs, ≈+58.9 dBm Digital
in level connect to the 4 way combiner.
The 4 Way combiner has three dummy
loads, two 600W and a 1200W, which
dissipate any power due to an imbalance
or mismatch during the combining of the
amplifiers. The output of the 4 Way
Combiner Assembly is at the 1 5/8” RF
output jack, typically ≈+64.1 dBm
Digital.

2.3.1.3: Description of the 3 Way
Combiner Assembly (1.8 kW
Amplifier Cabinet)

The RF outputs of the three amplifiers
are combined by means of a 3:1
combiner assembly that is mounted in
the middle of the cabinet.

The three RF inputs, ≈+58.9 dBm
Digital in level, each connect to an input
to the 3 Way combiner. The combiner
has two 600W dummy loads, which
dissipate any power due to an imbalance
or mismatch during the combining of the
amplifiers. The output of the 3 Way
Combiner Assembly is at the 1 5/8” RF
output jack, typically ≈+62.6 dBm
Digital.

2.3.2: Removal of an Amplifier
Assembly

The amplifiers are of broadband design
and cover the frequencies for the entire
UHF band without the need for
alignment or adjustment.

For reasons of safety, amplifier modules
MUST be in standby (RF disabled)
before any connections are removed. If
the amplifier control board is loaded
with software version 2.4 or higher, an
Axcera Amplifier disable plug (1308219)
can be used to place an individual
module in standby. If your amplifier
module has a front panel disable switch,
this switch can be used to disable the
amplifier. Regardless of the version of
code, any power amplifier may safely be
removed by disabling its power supply.
The power supply, either the top power
supply #1 for the top four Amplifier
assemblies, or the bottom power supply
#2 for the bottom three Amplifier
assemblies, may be isolated from main
AC power by switching off the
appropriate front panel circuit breaker.
This is accomplished by tripping the
respective breaker located on the circuit
breaker assembly panel, at the bottom
of the amplifier cabinet.

Volume 2, Rev. 0 2-9