BIRD Termaline 8890 Series User manual

Termaline® Load Resistor
Series 8890
Operation Manual

This unit requires the supplied vent plug be installed prior to use.
Operating the unit without the vent plug installed WILL result in equipment damage and may
cause personal injury.
© Copyright 2023 by Bird Technologies, Inc.
Instruction Book Part Number 920-8890S Rev. E
Termaline® and Tenuline® are Registered Trademarks
of Bird Electronic Corporation

Safety Precautions
i
Safety Precautions
The following are general safety precautions that are not necessarily related to any specific part or procedure, and
do not necessarily appear elsewhere in this publication. These precautions must be thoroughly understood and
apply to all phases of operation and maintenance.

Keep Away From Live Circuits
Operating Personnel must at all times observe general safety precautions. Do not replace
components or make adjustments to the inside of the test equipment with the high voltage
supply turned on. To avoid casualties, always remove power.

Shock Hazard
Do not attempt to remove the RF transmission line while RF power is present.

Do Not Service Or Adjust Alone
Under no circumstances should any person reach into an enclosure for the purpose of service or
adjustment of equipment except in the presence of someone who is capable of rendering aid.

Safety Earth Ground
An uninterruptible earth safety ground must be supplied from the main power source to test
instruments. Grounding one conductor of a two conductor power cable is not sufficient
protection. Serious injury or death can occur if this grounding is not properly supplied.

Resuscitation
Personnel working with or near high voltages should be familiar with modern methods of
resuscitation.

Remove Power
Observe general safety precautions. Do not open the instrument with the power on.

Termaline® Load Resistor
ii
Safety Symbols

Warnings call attention to a procedure, which if not correctly performed, could result in
personal injury.

Cautions call attention to a procedure, which if not correctly performed, could result in damage
to the instrument.

Calls attention to supplemental information.
This symbol indicates that a shock hazard exists if the precautions in the
instruction manual are not followed.
The caution symbol appears on the equipment indicating there is
important information in the instruction manual regarding that particular
area.
This symbol indicates that the unit radiates heat and should not be
touched while hot.
This symbol appears on the equipment and indicates the requirement for
separate collection of discarded electrical and electronic equipment in
accordance with the European Union Directive 2002/96/EC.

Safety Precautions
iii
Warning Statements
The following safety warnings appear in the text where there is danger to operating and maintenance personnel,
and are repeated here for emphasis.

The vent plug must be installed at all times when the unit is in operation or cooling.
Always check to ensure vent plug is installed prior to operation.
Failure to do so WILL result in damage to the equipment and endanger the operator’s safety.
On page 5, 7, 10, 11 and 19.

Never attempt to connect or disconnect RF equipment from the transmission line while RF
power is being applied. Leaking RF energy is a potential health hazard.
On page 8, 10, 12, 13 and 17.

Turn off AC power and RF power when attaching the power cable.
On page 9.

Do not touch the load during operation. During operation, load surfaces are extremely hot.
Touching the load during or after operation may cause burns.
On page 10 and 11.

Disconnect the blower assembly from supply voltage before performing any maintenance.
On page 13.

Disconnect the unit from all power sources before servicing. The unit may be energized from
multiple sources. The potential for electric shock exists.
On page 15, 18, and 20.

Do not operate with side panel removed. Doing so could result in personal injury.
On page 15.

Termaline® Load Resistor
iv
Caution Statements
The following equipment cautions appear in the text and are repeated here for emphasis.

This load is designed for operation in a horizontal position only, with the mounting brackets
down. Operation in any other orientation will cause insufficient cooling of the unit leading to
premature failure.
On page 5.

If installed, connect optional interlock before applying RF power.
On page 7, 10, and 11.

Check the local electrical code for proper AC hookup prior to operation of the unit. Make sure
the neutral or return hookup is only used for that purpose.
On page 9.

Make sure the interlock is properly connected when overloaded to prevent damage to the load.
On page 10.

Maximum power is 1,250 W when the blower is not running. If the indicator light should turn
off, immediately reduce RF power to less than 1,250 W.
On page 12.

Use only Bird coolant, P/N 5-1070, to prevent damage to the load.
On page 16.

Safety Precautions
v
Safety Statements
USAGE
ANY USE OF THIS INSTRUMENT IN A MANNER NOT SPECIFIED BY THE MANUFACTURER MAY
IMPAIR THE INSTRUMENT’S SAFETY PROTECTION.
USO
EL USO DE ESTE INSTRUMENTO DE MANERA NO ESPECIFICADA POR EL FABRICANTE, PUEDE
ANULAR LA PROTECCIÓN DE SEGURIDAD DEL INSTRUMENTO.
BENUTZUNG
WIRD DAS GERÄT AUF ANDERE WEISE VERWENDET ALS VOM HERSTELLER BESCHRIEBEN,
KANN DIE GERÄTESICHERHEIT BEEINTRÄCHTIGT WERDEN.
UTILISATION
TOUTE UTILISATION DE CET INSTRUMENT QUI N’EST PAS EXPLICITEMENT PRÉVUE PAR LE
FABRICANT PEUT ENDOMMAGER LE DISPOSITIF DE PROTECTION DE L’INSTRUMENT.
IMPIEGO
QUALORA QUESTO STRUMENTO VENISSE UTILIZZATO IN MODO DIVERSO DA COME
SPECIFICATO DAL PRODUTTORE LA PROZIONE DI SICUREZZA POTREBBE VENIRNE
COMPROMESSA.

Termaline® Load Resistor
vi
SERVICE
SERVICING INSTRUCTIONS ARE FOR USE BY SERVICE - TRAINED PERSONNEL ONLY. TO AVOID
DANGEROUS ELECTRIC SHOCK, DO NOT PERFORM ANY SERVICING UNLESS QUALIFIED TO DO
SO.
SERVICIO
LAS INSTRUCCIONES DE SERVICIO SON PARA USO EXCLUSIVO DEL PERSONAL DE SERVICIO
CAPACITADO. PARA EVITAR EL PELIGRO DE DESCARGAS ELÉCTRICAS, NO REALICE NINGÚN
SERVICIO A MENOS QUE ESTÉ CAPACITADO PARA HACERIO.
WARTUNG
ANWEISUNGEN FÜR DIE WARTUNG DES GERÄTES GELTEN NUR FÜR GESCHULTES
FACHPERSONAL.
ZUR VERMEIDUNG GEFÄHRLICHE, ELEKTRISCHE SCHOCKS, SIND WARTUNGSARBEITEN
AUSSCHLIEßLICH VON QUALIFIZIERTEM SERVICEPERSONAL DURCHZUFÜHREN.
ENTRENTIEN
L’EMPLOI DES INSTRUCTIONS D’ENTRETIEN DOIT ÊTRE RÉSERVÉ AU PERSONNEL FORMÉ AUX
OPÉRATIONS D’ENTRETIEN. POUR PRÉVENIR UN CHOC ÉLECTRIQUE DANGEREUX, NE PAS
EFFECTUER D’ENTRETIEN SI L’ON N’A PAS ÉTÉ QUALIFIÉ POUR CE FAIRE.
ASSISTENZA TECNICA
LE ISTRUZIONI RELATIVE ALL’ASSISTENZA SONO PREVISTE ESCLUSIVAMENTE PER IL
PERSONALE OPPORTUNAMENTE ADDESTRATO. PER EVITARE PERICOLOSE SCOSSE
ELETTRICHE NON EFFETTUARRE ALCUNA RIPARAZIONE A MENO CHE QUALIFICATI A FARLA.

Safety Precautions
vii
CONNECT INTERLOCK TO TRANSMITTER BEFORE OPERATING.
BRANCHER LE VERROUILLAGE À L'ÉMETTEUR AVANT EMPLOI.
CONECTE EL INTERBLOQUEO AL TRANSMISOR ANTES DE LA OPERACION.
VOR INBETRIEBNAHME VERRIEGELUNG AM SENDER ANSCHLIESSEN.
PRIMA DI METTERE IN FUNZIONE L'APPARECCHIO, COLLEGARE IL DISPOSITIVO DI BLOCCO AL
TRASMETTITORE.

Termaline® Load Resistor
viii
About This Manual
This manual covers the operating and maintenance instructions for the following models

When used in the rest of the manual, 8890 series refers to all models. 889x–300 refers only to
loads without a blower. –315 and –320 refer to loads with attached blowers.
Changes to this Manual
We have made every effort to ensure this manual is accurate. If you discover any errors, or if you have suggestions
for improving this manual, please send your comments to our Solon, Ohio factory. This manual may be periodically
updated. When inquiring about updates to this manual refer to the part number and revision on the title page.
Chapter Layout
Introduction — Describes the features of the Bird Termaline, Semiconductor, RF Load Resistor lists equipment
supplied and optional equipment, and provides power-up instructions.
Theory of Operation — Describes how the Termaline, Semiconductor, RF Load Resistor works and its functions.
Installation — Describes the how to install the Termaline, Semiconductor, RF Load Resistor.
Operation with Blower — Describes procedures require for operating the load resistor equipped with a blower
unit.
Maintenance — Lists routine maintenance tasks as well as troubleshooting for common problems. Specifications
and parts information are also included.
Connector
Model Number
Without
Blower
Blower,
115 VAC
Blower,
230 VAC
Female LC 8890-300 8890-315 8890-320
3-1/8" EIA Flanged 8891-300 8891-315 8891-320
1-5/8" EIA Flanged 8892-300 8892-315 8892-320
1-5/8" EIA Unflanged 8895-300 8895-315 8895-320
3-1/8" Unflanged, Flush Center, 51.58896-300
3-1/8" Unflanged, Flush Center 8897-300 8897-315 8897-320
3-1/8" Unflanged, Recessed Center 8898-300 8898-315 8898-320
Digital, 3-1/8" EIA Flanged 8891D300
Digital, 1-5/8" EIA Flanged 8892D300 8892D320
Digital, Female 13-30 8892D13-30

ix
Table of Contents
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .i
Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii
Warning Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Caution Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iv
Safety Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
About This Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii
Changes to this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .viii
Chapter Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .viii
Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Items Supplied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Items Required but not Supplied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Optional Accessories (889x –300) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Chapter 2 Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Load Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Thermal Interlock (Optional 889x – 300) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Blower Assembly (Optional 889x – 300) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Chapter 3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Unpacking and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Site and Shelter Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Tools Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Mounting the Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Vent Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Thermoswitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Installing the Thermoswitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Installing the Interlock Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Connecting RF Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Using a “QC” Connector Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Using a 13-30 Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Using a Swivel Flanged Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Using a Unflanged Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Using an AC Power Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Chapter 4 Operating Instructions, No Blower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Operating Under Abnormal Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Shutting Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Emergency Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Chapter 5 Operating Instructions, With Blower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Blower Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Operating Under Abnormal Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Shutting Down the Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Emergency Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Termaline® Load Resistor
x
Chapter 6 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Clean the Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Clean the Blower Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Inspect the Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Inspect the Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
RF Assembly Resistance Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
DC Resistance Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Replacing the RF Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Replacing the Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Replacing the Indicator Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Replacing the Load Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Replacing the Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Storage and Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Storing the Load Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Shipping the Load Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Available “QC” Type Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

1
Chapter 1 Introduction
The Bird 8890 series loads are portable, 50 ohm, coaxial RF transmission line terminations, designed for frequency
ranges of DC – 2.4 GHz. The 8890 series D loads are designed for use in the UHF (470 – 860 MHz) band, otherwise
they are identical to the standard series. These loads provide accurate and dependable low reflection line
terminations. Power is dissipated at a level of up to 2500 watts of RF, 5000 watts if the optional blower assembly is
used.
The 8890 series –300 is the basic load. The –315 and –320 models consist of a load with an installed blower
assembly for 115 or 230 VAC lines, respectively.
The load has a coolant chamber surrounded by radiator fins. The front and rear fins form mounting flanges which
can be used as supports for freestanding use or as brackets for fixed mounting. A vent plug at the top of the unit
relieves internal pressure from coolant expansion. The load’s simple and rugged design minimizes maintenance
requirements.
Items Supplied

The load is pre-filled with coolant at the factory.
Load Resistor
Shipping Plug
Vent Plug
Instruction Manual
Items Required but not Supplied
Coupling Kit: Connects the load to the RF line
Optional Accessories (889x –300)

The blower and control thermoswitch are standard on the –315 and –320 loads.
Bird BA-310 Blower Assembly: Doubles the RF power capacity of the load. Includes control thermoswitch
and detachable 3-wire power cable (without male plug for 230 VAC cable)
Interlock Thermoswitch: Automatically shuts off the transmitter to prevent overheating of the load.

Termaline® Load Resistor
2
Figure 1 Bird 889x Series Outline Drawing - No Blower
Figure 2 Bird 889x Series Outline Drawing With Blower
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3
Chapter 2 Theory of Operation
Load Resistor
Bird 8890 series loads consist of a thin-film-on-ceramic resistor immersed in a dielectric coolant. The resistor,
individually selected for its accuracy, is enclosed in a special housing. When surrounded by the coolant, this
produces a uniform, practically reflectionless line termination over the specified frequencies.
Coolant
The load is cooled by natural fluid and air convection currents. The coolant, chosen for its dielectric and thermal
characteristics, carries heat from the resistor to the walls of the cooling tank, where radiator fins surrounding the
tank transfer the heat to the air.
When the coolant is heated, thermal expansion causes an increase in the internal pressure. The vent plug (
Figure 1 )
relieves this pressure while protecting the opening from dirt or other contaminants.
Thermal Interlock (Optional 889x – 300)
When installed, a passive, normally closed over-temperature thermoswitch opens above the maximum safe load
temperature of 236 °C (457 °F), turning off transmitter power. The interlock will not permit use of the transmitter
until the load has reached a safe temperature.
Blower Assembly (Optional 889x – 300)
When installed, the blower assembly provides forced airflow with two blowers. Baffles direct the airflow from the
blowers over the radiator fins, doubling the heat transfer efficiency.
Example - A 2.5 kW load will safely dissipate 5 kW. A passive, normally open control
thermoswitch closes when the coolant reaches 155 °C (311 °F), turning the fans on.
The baffles interfere with the free flow of normal air currents, causing a 50% reduction in heat transfer efficiency if
the forced airflow is stopped. Thus, a 2.5 kW load will have its maximum power dissipation reduced to 1.25 kW.

4
Chapter 3 Installation
Unpacking and Inspection
1. Carefully inspect shipping container for signs of damage.
If the shipping container is damaged, do not unpack the unit. Immediately notify the shipping carrier and
Bird Technologies.
If the shipping container is not damaged, unpack the unit. Save shipping materials for repackaging.
2. Inspect unit for visual signs of damage.

If there is damage, immediately notify the shipping carrier and Bird Technologies.
Site and Shelter Requirements
The unit should be operated in a dry, dust and vibration free environment.
Do not use outdoors or in areas of condensing humidity.
The ambient temperature range should remain between – 40 to +45 °C (– 40 to +113 °F) for proper operation.
Allow at least 12" (305 mm) of clearance around the unit to permit an unimpeded access of convection air currents
for adequate heat dissipation.
Place the unit as close as possible to the transmitting equipment, to permit the shortest possible cable length.
Tools Required
The following tools and supplies will be required to prepare the unit for use:
Wrenches
Screwdrivers
Bolt and nut sets or lag screws for mounting) (38“(9.53 mm) max. diameter)
These tools and supplies are required for 889x-300 optional thermoswitch installation:
9/16 Hex wrench
Pipe sealing compound (Loctite 567, or equivalent)
Soldering Iron and solder
Torque Wrench

Installation
5
Mounting the Load

This load is designed for operation in a horizontal position only, with the mounting brackets
down. Operation in any other orientation will cause insufficient cooling of the unit leading to
premature failure.
Bird 8890 series Loads are equipped for either portable use or fixed installation. The mounting brackets on the front
and rear faces have four mounting slots arranged in a 412" x 202332" rectangle (114.3 x 526.3 mm). Use a screw with
a 38" (9.53 mm) diameter max.
The following instructions are for mounting the unit to a suitable surface.
1. Place the unit on a flat surface.
2. Insert the bolts through the surface and the mounting slots.
3. Secure the bolts with nuts and lock washers.
Vent Plug

The vent plug must be installed at all times when the unit is in operation or cooling.
Always check to ensure vent plug is installed prior to operation.
Failure to do so WILL result in damage to the equipment and endanger the operator’s safety.
Before placing the attenuator into service, the solid shipping plug, P/N 2450-049, must be removed and replaced by
the spring loaded vent plug, P/N 2450-094. The two plugs are linked together by a short length of bead chain.
1. Locate the vent hole for the plug, located at the top left hand side near the front.
See
Figure 1 and Figure 2 on page 2 .
2. Remove the shipping plug.
3. Verify the O-Ring is installed on the vent plug.
4. Install the vent plug.

Termaline® Load Resistor
6
Thermoswitch
As an option, the load may be provided with a thermoswitch assembly, P/N 8890-008. The thermoswitch is used as
an interlock switch to disable transmitter power if the coolant temperature exceeds a preset temperature, thus
preventing possible damage from accidental power overloading from the transmitter or equipment malfunction.
The thermoswitch is normally closed and opens at a maximum safe temperature. Since the thermoswitch is
connected in series with the transmitter interlock, it cuts off transmitter power if the coolant temperature exceeds
this value.
The assembly consists of:
Thermoswitch - P/N 8890-005
Connector - P/N 2450-018
Installing the Thermoswitch
Bird 8890 series Load thermoswitch is normally closed, opening at 155 °C (311 °F), with a rating of 10A at 120VAC
and 5A at 230VAC.

A control thermoswitch, P/N 2450-085, is used to control the optional blower assembly. It is
normally open, closing at 155 °C (311 °F), with a rating of 10A @ 120VAC and 5A @ 230VAC.
1. Remove the vent plug.
2. Verify the O-Ring is installed on the shipping plug.
3. Install the shipping plug.
4. Remove AC power plug from models equipped with a blower.
5. Stand the unit on its back with the RF connector end up.

In this position there is no danger of the coolant pouring out through the socket plug hole.
6. Do one of the following:
For Interlock Thermoswitch:
Remove the socket plug just above the connector assembly with a 916" hex wrench. See
Figure 1 and
Figure 2 on page 2 .
For Control Thermoswitch:
Remove the top socket plug with a 916" hex wrench.

Do not contaminate the coolant with pipe sealing compound.
7. Use an acceptable pipe sealing compound sparingly on only the external threads of the thermoswitch.
8. Install the thermoswitch in place of the plug. Torque to 40 +/-2 ft-lbs.
9. Lower the attenuator back onto its feet.
10. Check the unit for coolant leaks.

Installation
7

The vent plug must be used at all times when the unit is in operation or cooling.
Always check to ensure vent plug is installed prior to operation.
Failure to do so WILL result in damage to the equipment and endanger the operator’s safety.
11. Remove the shipping plug.
12. Verify the O-Ring is installed on the vent plug.
13. Install the vent plug.
Installing the Interlock Connection

If installed, connect optional interlock before applying RF power.
1. Unscrew the large knurled ring-nut (A) at the lower end of the coupling jack assembly.
2. Pull the large knurled nut off the thermoswitch jack (B). See
Figure 3 on page 7 .
3. Unscrew the small knurled cover fitting from the base plug (D) of the connector to release the base.
4. Thread the control switch wires through the clamp (E) with the washers (F) inside and with its threaded fitting in
place.
5. Service the control switch wire with short tips and put spaghetti sleeves over the wire ends if necessary.
6. Securely solder the control switch leads to the lugs (G) of the connector base.

The ring-nut (A) must be in place over the base plug (D) with the knurled end facing out.
7. Screw on the cover ring (C).
8. Fasten the cable clamp (E) in place.
9. Tighten both yoke screws (H).
10. Push the plug back on the thermoswitch.
11. Tighten the nut (A).

Do not attempt to operate the equipment without the interlock attached.
12. Connect the Thermoswitch wiring to the transmitter’s interlock.
Figure 3 Thermoswitch Assembly

Termaline® Load Resistor
8
Connecting RF Power
Before first using the load, perform the following steps.
1. Wipe all connectors and insulator surfaces on the transmission line face with a clean soft cloth.
2. Check the RF input connector for signs of wear, damage, or dirt.
3. Clean the connector if necessary. Use a self-drying, non-residue forming contact cleaner on the interior portions
of the connector.
4. Check the input resistance of the load. Refer to
"RF Assembly Resistance Test" on page 16 for details.
5. The RF transmission line can be attached using standard coaxial line coupling kits.

Never attempt to connect or disconnect RF equipment from the transmission line while RF
power is being applied. Leaking RF energy is a potential health hazard.
Using a “QC” Connector Coupling
Use a 50 ohm coaxial cable such as RG-218/U or -220/U (-17A or -19A), appropriate for the frequency and power
level of operation.

Use a cable connector which will mate with the one on the load.
Using a 13-30 Coupling
Use 50 ohm coaxial cable such as RG-8A/U, RG-9U, RG-213/U, or equivalent with a male 13-30 plug.
Using a Swivel Flanged Coupling
1. Insert the center bullet. See
Figure 4 on page 8 .
2. Push it in until it is fully seated.
3. Connect the coaxial input in a straight line
4. Push, carefully, on the center conductor to close.

The swivel flange on the load makes connection independent of the orientation of the fixed
flange on the coaxial input outer conductor.
5. Insert the bolt sets and tighten evenly all around to transmission line manufacturer’s recommended torque.

Use all of the bolts.
Figure 4 Swivel Flanged Coupling
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