BIRD TERMALINE 8860 Series User manual

TERMALINE®LOAD RESISTOR
SERIES 8860
COVERING MODELS
©Copyright 2012 by Bird Electronic Corporation
Instruction Book Part Number 920-8860S Rev. D
Termaline®and Tenuline®are Registered Trademarks
of Bird Electronic Corporation

I am not blank

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 precau-
tions must be thoroughly understood and apply to all phases of operation and maintenance.
Safety Symbols
WARNING
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.
WARNING
Shock Hazard
Do not attempt to remove the RF transmission line while RF power is present.
WARNING
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.
WARNING
Safety Earth Ground
An uniterruptible 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.
WARNING
Resuscitation
Personnel working with or near high voltages should be familiar with modern methods of
resuscitation.
WARNING
Remove Power
Observe general safety precautions. Do not open the instrument with the power on.
WARNING
Warning notes call attention to a procedure, which if not correctly performed, could result
in personal injury.
CAUTION
Caution notes call attention to a procedure, which if not correctly performed, could result in
damage to the instrument.

ii
Note: Calls attention to supplemental information.
Warning Statements
The following safety warnings appear in the text where there is danger to operating and mainte-
nance personnel, and are repeated here for emphasis.
See page 5.
See pages 7, 9, 11, and 12.
See pages 11 and 13.
See pages 11, 12, 13, and 14.
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 impor-
tant information in the instruction manual regarding that particular area.
This symbol indicates that the unit radiates heat and should not be touched
while hot.
WARNING
The vent plug must be used at all times when the unit is operating or cooling. Failure to do
so could result in an explosion or severe burns.
WARNING
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.
WARNING
Disconnect the unit from all power sources before servicing.
The unit may be energized from multiple sources.
The potential for electric shock exists.
WARNING
Oil is slippery. If a leak occurs, be careful not to fall.

iii
Caution Statements
The following equipment cautions appear in the text and are repeated here for emphasis.
See pages 5.
See pages 6.
See pages 6.
See pages 13.
CAUTION
This load is designed for operation in a horizontal position only, with the vent plug up. Do
not use in any other manner.
CAUTION
Do not contaminate the coolant with pipe sealant.
CAUTION
If installed, connect optional interlock before applying RF power.
CAUTION
Use only Bird coolant, P/N 5-1070, to prevent damage to the load.

iv
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.

v
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.

vi
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.

vii
About This Manual
This manual covers the operating and maintenance instructions for the following models:
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 fac-
tory. 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 prob-
lems. Specifications and parts information are also included..
8860

viii
Table of Contents
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
Warning Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ii
Caution Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Safety Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vii
Changes to this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vii
Chapter Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vii
Chapter 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Items Supplied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Items Required but not Supplied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Optional Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Chapter 2 Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Load Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Thermal Interlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Chapter 3 Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
UUnpacking and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Installing Thermoswitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Interlock Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Connecting RF Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
“QC” Connector Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
13-30 Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Swivel Flanged Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Unflanged Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chapter 4 Operating Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Operation Under Abnormal Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Emergency Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Chapter 5 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
DC Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Inspecting the Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Replacing the RF Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Replacing the Load Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Storage and Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Storing the Load Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Shipping the Load Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Available “QC” Type Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

1
Chapter 1 Introduction
Bird 8860 Series Loads are portable 50 ohm coaxial RF transmission line terminations, designed for frequency ranges
of dc – 2000 MHz. Bird 8860D Series Loads are identical, except that they are designed for the UHF (470 – 860 MHz)
band. They provide accurate, dependable, and low reflection line terminations. Up to 1500 watts of RF power can be
dissipated.
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
•Load Resistor: Pre-filled with coolant at the factory
•Shipping Plug
•Vent Plug
•Instruction Manual
Items Required but not Supplied
•Coupling Kit: Connects the load to the RF line
Optional Accessories
•Interlock Thermoswitch: Automatically shuts off the transmitter to prevent over-
heating of the load
Figure 1 Bird 8860 Series Outline Drawing
MTG. HOLE
DETAIL
13/32”
(10 mm)
3/32”
(2.4 mm)
3/8”
(9.5 mm)
(4) MTG. HOLES
SEE DETAIL
4.5”
(114 mm)
7.5”
(190 mm)
15-7/8”
(403 mm)
13-1/8”
(333 mm)
3”
(75 mm)
DEPENDS ON
CONNECTOR
INTERLOCK
THERMOSWITCH
(OPTIONAL)
VENT PLUG
15-1/4”
(387 mm)

2

3
Chapter 2 Theory of Operation
Load Resistor
Bird 8860 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 relieves
this pressure while protecting the opening from dirt or other contaminants.
Thermal Interlock
Loads can be supplied with an optional passive overtemperature thermoswitch. Normally closed, it opens at the
maximum safe load temperature of 236 °C (457 °F), turning off transmitter power. The interlock system will not per-
mit reoperation of the transmitter until the load has reached a lower, safe temperature.
Figure 2 Shipping Plug
Figure 3 Vent Plug
O-ring seal
O-ring seal

4

5
Chapter 3 Installation
This chapter provides information for on-site requirements, unpacking, inspection, and preparing the load for use.
UUnpacking and Inspection
1. Carefully inspect shipping container for signs of damage.
2. Do one of the following:
•If the shipping container is damaged, do not unpack the unit. Immediately notify
the shipping carrier and Bird Electronic Corporation.
•If the shipping container is not damaged, unpack the unit. Save shipping materi-
als for repackaging.
3. Inspect unit for visual signs of damage.
Note: If there is damage, immediately notify the shipping carrier and Bird Elec-
tronic Corporation.
Setup
Note: Before first using the load, get a resistance baseline for future maintenance. Refer to "DC Resistance"
on page 12 for details.
1. Remove the shipping plug from the load.
2. Replace the shipping plug with the vent plug. Refer to Figure 1 and Figure 2 for pic-
tures of the plugs.
Mounting
Place the load in a dry, dust and vibration free environment. Do not use outdoors or in areas of condensing humidity.
Allow at least 12" (30 cm) of clearance on all sides of the load.
These 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 147⁄32" rectangle (114.3 x 361.2 mm). Use a screw with a 3⁄8"
(9.53 mm) diameter max.
WARNING
The vent plug must be used at all times when the unit is operating or cooling. Failure to
do so could result in an explosion or severe burns.
CAUTION
This load is designed for operation in a horizontal position only, with the vent plug up. Do not use in any other manner.

6
Installing Thermoswitch
Bird 8860 series loads can be equipped with an optional interlock thermoswitch, P/N 8890-008. It is normally closed,
opening at 236 °C (457 °F), with a rating of 10A @ 120Vac and 5A @ 230Vac.
1. Remove the vent plug.
2. Install the shipping plug.
3. Stand the unit on its front, supporting it so that the connector is not damaged.
Note: In this position there is no danger of the coolant pouring out through
the socket plug hole.
4. Remove the socket plug just above the connector assembly, using a 9⁄16" hex wrench.
5. Replace the plug with the thermoswitch.
6. Apply pipe sealing compound to the external threads of the thermoswitch sparingly,
ONLY.
1. Check for coolant leaks upon completion.
Interlock Connection
1. Unscrew the large knurled ring-nut (A) at the lower end of the coupling jack assembly.
2. Pull the large knurled ring-nut off the thermoswitch jack (B).
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.
Note: 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, then fasten the cable clamp (E) in place and tighten both
yoke screws (H).
2. Put the plug back on the thermoswitch and tighten the nut (A).
WARNING
The vent plug must be used at all times when the unit is operating or cooling. Failure to do so could result in an
explosion or severe burns.
CAUTION
Do not contaminate the coolant with pipe sealant.
CAUTION
If installed, connect optional interlock before applying RF power.

7
Figure 4 Thermoswitch Assembly
Connecting RF Power
After installing the load, the RF transmission line can be attached using standard coaxial line coupling kits.
“QC” Connector Coupling
Use 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.
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.
Swivel Flanged Coupling
Note: To couple the swivel flange with a flanged RF transmission line, use an
appropriate coupling kit. Refer to Figure 5.
1. Insert the center bullet.
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.
Note: The swivel flange on the load makes connection independent of the ori-
entation of the fixed flange on the coaxial input outer conductor.
5. Insert the bolt sets.
6. Tighten evenly all around to transmission line manufacturer’s recommended torque.
Note: Use all of the bolts.
WARNING
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.

8
Figure 5 Swivel Flanged Coupling
Unflanged Coupling
To couple the unflanged connector with an unflanged RF line, use an appropriate coupling kit. Refer to Figure 6
while following the instructions below:
1. Insert the center bullet.
2. Bottom it on the midpoint nibs.
3. Position the outer sleeve, with clamping bands, over the input connector.
4. Set the transmission line snugly against the coupling stops.
5. Position the clamping bands evenly about 3/4” from the ends of the sleeve.
6. Tighten the clamping bands.
Figure 6 Unflanged Coupling
BOLT BULLET LOADRF COAXIAL LINE
RF COAXIAL
LINE
CLAMPING
BANDS
CONNECTOR
SLEEVE
BULLET LOAD

9
Chapter 4 Operating Instructions
Normal Operation
Bird 8860 series Loads have no indicators or operating controls. They require no special operating procedures or sur-
veillance when their performance limits are not exceeded. Follow the instructions for the specific transmitter equip-
ment.
Operation Under Abnormal Conditions
The load can be subjected to moderate overloads for short periods. If this is likely, make sure the interlock is prop-
erly connected to prevent damage to the load.
Shutdown
These loads are passive devices, so have no way of being turned off. Turn off RF power at the source.
Emergency Shutdown
Turn off RF power at the source.
If the interlock thermoswitch is properly connected, RF power will be automatically turned off when the coolant
temperature reaches an unsafe level.
WARNING
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.

10