INSTRUCTION BOOK
OPERATING INSTRUCTIONS
SERIES 6730B
TERMALINE® WATTMETER
Electronic Corporation
Cleveland(Solon)Ohio USA
© Copyright 1997 by Bird Electronic Corporation
Instruction Book Part Number 920-6730B Rev. B
®
Termaline
is a Registered Trademark
of Bird Electronic Corporation
Limited Warranty
All products manufactured by Seller are warranted to be free from defects in
material and workmanship for a period of one (1) year, unless otherwise spec
ified, from date of shipment and to conform to applicable specifications, draw
ings, blueprints and/or samples. Seller’s sole obligation under these
warranties shall be to issue credit, repair or replace any item or part thereof
which is proved to be other than as warranted; no allowance shall be made for
any labor charges of Buyer for replacement of parts, adjustment or repairs, or
any other work, unless such charges are authorized in advance by Seller.
If Seller’s products are claimed to be defective in material or workmanship or
not to conform to specifications, drawings, blueprints and/or samples, Seller
shall, upon prompt notice thereof, either examine the products where they
are located or issue shipping instructions for return to Seller (transportation-charges prepaid by Buyer). In the event any of our products are proved to
be other than as warranted, transportation costs (cheapest way) to and from
Seller’s plant, will be borne by Seller and reimbursement or credit will be
made for amounts so expended by Buyer. Every such claim for breach of these
warranties shall be deemed to be waived by Buyer unless made in writing
within ten (10) days from the date of discovery of the defect.
The above warranties shall not extend to any products or parts thereof which
have been subjected to any misuse or neglect, damaged by accident, rendered
defective by reason of improper installation or by the performance of repairs
or alterations outside of our plant, and shall not apply to any goods or parts
thereof furnished by Buyer or acquired from others at Buyer’s request and/or
to Buyer’s specifications. In addition, Seller’s warranties do not extend to the
failure of tubes, transistors, fuses and batteries, or to other equipment and
parts manufactured by others except to the extent of the original manufac
turer’s warranty to Seller.
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The obligations under the foregoing warranties are limited to the precise
terms thereof. These warranties provide exclusive remedies, expressly in lieu
of all other remedies including claims for special or consequential damages.
SELLER NEITHER MAKES NOR ASSUMES ANY OTHER WARRANTY
WHATSOEVER, WHETHER EXPRESS, STATUTORY, OR IMPLIED, IN
CLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS, AND
NO PERSON IS AUTHORIZED TO ASSUME FOR SELLER ANY OBLIGA
TION OR LIABILITY NOT STRICTLY IN ACCORDANCE WITH THE
FOREGOING.
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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 normal safety regulations. Do
not replace components or make adjustments to the inside of the test equip
ment with the high voltage supply turned on. To avoid casualties, always dis
connect power.
DO NOT SERVICE OR ADJUST ALONE
Operating personnel must at all times observe normal safety regulations. Do
not attempt to replace parts or disconnect a RF transmission or any other
high voltage line while power is applied. When working with high voltage always have someone present who is capable of rendering aid if necessary. Personnel working with or near high voltage should be familiar with modern
methods of resuscitation.
SAFETY EARTH GROUND
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An uninterruptible earth safety ground must be supplied from the main
power source to test instruments. Grounding one conductor of a two conduc
tor power cable is not sufficient protection. Serious injury or death can occur
if this grounding is not properly supplied.
SHOCK HAZARD
HIGH VOLTAGE is used in the operation of this equipment. DEATH ON
CONTACT may result if personnel fail to observe safety precautions. Learn
the areas containing high voltages in each part of the equipment. Be careful
not to contact high voltage connections when installing or operating this
equipment.
CHEMICAL HAZARD
Solvents used to clean parts are potentially dangerous. Avoid inhalation of
fumes and also prolonged skin contact.
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i
RESUSCITATION
Personnel working with or near high voltages should be familiar with modern
methods of resuscitation. Such information may be obtained from the Bureau
of Medicine and Surgery.
SAFETY SYMBOLS
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.
6730B 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.
WARNING
Before applying RF power to the Models 6735-300A, 6736-030A or 6736A
be sure to remove the shipping plug, P/N 2450-049 located near or on
top of the radiator. Replace the shipping plug with the supplied breather
vent plug, P/N 2450-094. This is important as internal pressure build-up,
caused by expansion of the heated dielectric coolant, could cause damage
to the equipment and injury to the operator.
WARNING
When the unit is used in the upper range of its power capacity, the
radiator will become hot - care should be used in touching the
equipment.
WARNING
Do not attempt to operate the Termaline Wattmeter for prolonged
periods at higher than rated load levels. Damage to the equipment and
injury to the operator may result.
WARNING
Never attempt to disconnect any RF equipment from the transmission
line while RF power is being applied. Leaking RF energy is a potential
health hazard.
ii
6730B CAUTION STATEMENTS
The following equipment cautions appear in the text whenever the equipment
is in danger of damage and are repeated here for emphasis.
CAUTION
Model 6735-300A is rated for 1200 W operation for a maximum of ½
hour only. For continuous operation, the maximum wattage should be
restricted to 1000 W. It is recommended that if frequent use above 1000
W is contemplated, the instrument be equipped with the thermoswitch
assembly.
CAUTION
Do not replace coolant with anything but the specified fluid. The inner
shell of the resistor housing is contoured to the dielectric properties of
this fluid. The use of any other type of coolant will affect the electrical
performance of the load.
iii
About This Manual
This instruction book covers the models 6732B, 6734B, 6734B-030,
6735-300A, 6736A, 6736-030A, 6737A, and 6737-030A Termaline Wattmeter.
This instruction book is arranged so that essential information on safety is
contained in the front of the book. Reading the Safety Precautions Section
before operating the equipment is strongly advised.
The remainder of this Instruction Book is divided into Chapters and Sections.
At the beginning of each chapter a general overview will be given, describing
the contents of that chapter
OPERATION
First time operators should read Chapter 1 - Introduction, and Chapter 3 Installation, to get an overview of equipment capabilities and how to install
it. An experienced operator can refer to Chapter 4 - Operating Instructions.
All instructions necessary to operate the equipment, are contained in this
section.
MAINTENANCE
All personnel should be familiar with preventative maintenance found in
Chapter 5 - Maintenance. If a failure should occur, the troubleshooting sec
tion will aid in isolating and repairing the failure.
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PARTS
For location of major assemblies or parts refer to the part lists and associated
drawings in Chapter 5.
CHANGES TO THIS MANUAL
We have made every effort to ensure this manual is accurate at the time of
publication. If you should discover any errors or if you have suggestions for
improving this manual, please send your comment to our factory. This
manual may be periodically updated, when inquiring about updates to this
manual refer to the part number and revision level on the title page.
iv
TABLE OF CONTENTS
Safety Precautions ......................i
Warning Statements ....................ii
Caution Statements ....................iii
About This Manual .....................iv
Introduction .........................1
Purpose and Function ...................1
Dimensions and Weight ..................1
Power and Utility Requirements ...............1
Environmental Requirements ................2
Items Furnished ......................2
Optional Items ......................2
Items Required ......................2
Principles of Operation ....................5
Cooling..........................6
Installation .........................9
Mounting Rectangle ....................9
Installing the Vent Plug ..................9
Installing the Thermoswitch ................10
Connecting the Thermoswitch ...............11
Operating Instructions ...................13
Controls .........................13
Start-Up ........................13
Normal Operation ....................13
v
Operation Under Emergency, Adverse, or Abnormal Conditions . 14
Shutdown ........................14
Emergency Shutdown ...................14
Maintenance ........................15
Troubleshooting.........................15
Cleaning ............................16
Outside Surfaces .....................16
Radiator.........................16
Inspection ...........................16
Preventive Maintenance .....................16
RF Assembly Test ........................16
Disassembly ..........................17
RF Connector ......................17
Diaphragm and Coolant Oil ................18
RF Load Resistor .....................19
Assembly ...........................21
RF Connector ......................21
Diaphragm and Coolant Oil ................21
RF Load Resistor .....................22
Storage ............................22
Shipment ...........................22
Load Portion .......................22
Meter Portion ......................22
Low Frequency Line Section ................22
Customer Service ........................23
Replacement Parts List ...................24
vi
Chapter 1
Introduction
This instruction book is intended for use by operators of
the Models 6732B, 6734B, 6734B030, 6735-300A, 6736A,
6736-030A, 6737A, and 6737-030A Termaline Wattmeter.
This chapter contains introductory information including
product specifications, items supplied, and accessory items
available.
Purpose
and
Function
Dimensions
and Weight
A Series 6730B Termaline Wattmeter is a portable direct
reading absorption wattmeter that both measures and
dissipates RF power. It is a self-contained unit that re
quires no outside power source or additional equipment,
except for the Models 6737A and 6737-030A which must
have auxiliary water cooling. The load portion forms an
accurate, dependable and practically non-reflective 50
ohm termination for the adjustment, standby and testing
of transmitters under nonradiating conditions.
These Termaline Wattmeters can safely measure and absorb their maximum rated RF power. The low frequency
units will measure power to within ±5 percent of full
scale over the frequency band of 2 to 32 MHz. The rest of
their frequency range permits power measurement to ±10
percent of full scale. The high frequency units measure to
±5 percent of full scale from 25 to 512 MHz and ±10 per
cent of full scale from 512 to 1000 MHz. Each meter has
three switch selectable scales and is housed separately
from the load.
The dimensions of the individual loads are given in the
specifications on page 3. The meter housings are 5 9/16
inchWx6½inchHx411/64 inch D (141 x 165 x 106
mm) for the Model 6735, 6736, and 6737 series and 3 7/8
inchWx55/8inchHx37/8inch D (98 x 143 x 98
mm) for the Model 6732 and 6734 series. The total
weight for each wattmeter is also given in the
specifications. The shipping weights will run approxi
mately 20 percent higher.
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Power and
Utility
Require-
ments
The Series 6730B Termaline Wattmeters require no exter
nal source of electrical power other than the RF input
power for operation. The Models 6737A and 6737-030A
do, however, depend on a supplemental water supply for
cooling.
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1
Bird Model 6730B Series Termaline Wattmeter
Environ-
mental
Require-
ments
Items
Furnished
Optional
Items
Items
Required
These wattmeters should be operated in a dust and vibra
tion free environment. The ambient temperature range
should remain between -40°C and +45°C (-40°F and
+113°F) for proper operation. Allow at least 6 inches (150
mm) of clearance around the units to permit unimpeded
access of natural air convection currents for adequate
heat dissipation.
These models consist of a load with a line section/voltme
ter assembly RF input. The meter assembly is connected
to the voltmeter through a dc cable assembly. This in
struction book, part number 920-6730B is the only other
item furnished with these models.
The models 6734B030, 6736-030A, and 6737-030A are
equipped with a special low frequency line section P/N
6734-034. This line section can also be ordered as an op
tion to convert the models 6734B, 6736A, or 6737A to the
low frequency (-030) version.
A matching connector to the wattmeter is needed on the
coaxial transmission line. Water cooled Models 6737A and
6737-030A must also have a conveniently located water
supply and a drain.
Only simple tools such as screwdrivers will be necessary
for disassembly of this equipment. A resistance bridge or
ohmmeter with an accuracy of at least ± 1% at 50 ohms
is useful for checking the resistance value of the RF section assembly.
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2
Introduction
Specifications
Impedance 50 ohms nominal
VSWR
6734B030, 6736-030A
6737-030A 1.10:1.00 max. dc - 35MHz
6734B, 6736A,
6735-300A, 6737A 1.15:1.00 max. dc - 1000MHz
6732B 1.15:1.00 max. dc - 800MHz
1.20:1.00 max. 800 - 1000MHz
Accuracy
6734B030
± 5% of full scale 2 - 32MHz
6736-030A
6737-030A
6732B, 6734B, 6736A,
6735-300A, 6737A
Ambient Temperature -40°C to +45°C (-40°F to +113°F)
Cooling Method
All Models Oil dielectric & air convection currents
6737A & 6737-030A Supplemental water cooling
Operating Position
6737A & 6737-030A Vertical - connector down with water
All other models Horizontal
Finish Light navy gray baked enamel
± 5% of full scale 2 - 30MHz
± 10% of full scale 1.5 - 2MHz
30 - 32MHz
± 5% of full scale 2 - 32MHz
± 10% of full scale 1.5 - 2MHz
32 - 35MHz
± 5% of full scale 25 - 512MHz
± 10% of full scale 512 - 1000MHz
(MIL-E-15090)
—specifications continued on next page—
3
Introduction
6735-202-2
Load Meter
lbs/kg
Conn. Overall Dimensions Weight
MHz
13.7/6.2 8141 6732B002-1
23.7/10.8 8201 6732B002-2
(321 X 216 X 151MM)
23.7/10.8 8201 6732B002-3
(506 X 216 X 151MM)
63/28.6 8830-
(506 X 216 X 151MM)
300
30/13.6 8251 6735-202-5
(664 X 437 X 181MM)
30/13.6 8251 6735-202-8
(533 X 216 X 151MM)
33/15 8230 6735-202-3
(533 X 216 X 151MM)
33/15 8230 6735-202-9
(529 X 216 X 151MM)
(529 X 216 X 151MM)
500 Watts horizontal position
Model Max. Power Watts Scale Freq
6732B 250 10/50/250 25-1000 N-F 12-5/8L X 8-1/2H X 5-15/16"W
6734B 500 25/100/500 25-1000 N-F 19-15/16L X 8-1/2H X 5-15/16"W
6734B030 500 25/100/500 1.5-35 N-F 19-15/16L X 8-1/2H X 5-15/16"W
6735-300A 1200* 120/600/1200 25-1000 LC-F 26-1/8L X 17-3/16H X 7-1/8"W
6736A 1000 50/250/1000 25-1000 LC-F 21-15/16L X 8-1/2H X 5-15/16"W
6736-030A 1000 50/250/1000 1.5-35 LC-F 21-15/16L X 8-1/2H X 5-15/16"W
6737A 200/500/2500** 100/500/2500 25-1000 LC-F 20-13/16L X 8-1/2H X 5-15/16"W
6737-030A 200/500/2500** 100/500/2500 1.5-35 LC-F 20-13/16L X 8-1/2H X 5-15/16"W
* For ½ hour only, for continuous operation: 1000W
2500 Watts vertical position, water flowing
** 200 Watts vertical position, no water flow
4
Chapter 2
Principles of Operation
The Termaline Wattmeter circuit is basically a voltage
capacitive divider with one of the capacitors being a
probe whose distance from the center conductor deter
mines its capacitive value. This probe spacing is adjusted
at the factory in the calibration procedure to produce the
required value and is then locked in place. The small
voltage developed across the fixed capacitor is rectified by
a diode. A simple RC filter eliminates any RF present
and the rectified dc current is fed to the meter, see the
schematic diagrams on the following pages.
The wattmeter measures three separate power ranges by
selectively switching various values of resistance in series
with the meter. One of the two resistors in each range is
adjustable and is set and sealed at the factory during the
calibration procedure. These resistors are mounted on the
back of the meter itself and the range selector switch is
located on the front panel of the meter housing.
Mechanically, the wattmeter section consists of a 50 ohm
line section mounted on the load. For the Models 6732B,
6734B, 6735-300A, 6736A and 6737A, a socket is used to
hold the voltmeter cartridge that contains the crystal diode. The meter cable is screwed directly on top of the
voltmeter cartridge to complete the assembly. The Models
6734B030, 6736-030A and 6737-030A utilize a line section
with an attached voltmeter block. The meter cable atta
ches directly on top of the voltmeter block.
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The Termaline load consists essentially of a carbon film
resistor on a ceramic substrate immersed in a dielectric
coolant. The resistor, individually selected for its accu
racy, is enclosed in a special exponentially tapered hous
ing. This provides a linear reduction in surge impedance
directly proportional to the distance along the resistor.
When surrounded by the dielectric coolant, the character
istic impedance is therefore; 50 ohms at the front (connec
tor) end, 25 ohms at the mid-point, to compensate for the
resistance already passed over, and zero ohms at the rear
where the resistor joins the housing, forming the return
conductor of the coaxial circuit. This produces a uniform,
practically reflectionless line termination over the stated
frequencies of the load resistor.
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5
Bird Model 6730B Series Termaline Wattmeter
CAUTION
Model 6735-300A is rated for 1200 W operation for a
maximum of ½ hour only. For continuous operation, the
maximum wattage should be restricted to 1000 W. It is
recommended that if frequent use above
1000 W is contemplated, the instrument be equipped
with the thermoswitch assembly.
As an optional item, the Model 6735-300A load portion
can be provided with a thermoswitch assembly, P/N
2450-056. When installed in the radiator, it will prevent
possible damage occurring from accidental transmitter
power overload or equipment malfunction. Being normally
closed, the thermoswitch opens at a maximum safe tem
perature of +155°C (+311°F). Connected in series with the
transmitter interlock, it cuts off transmitter power if the
load coolant temperature exceeds this value. The assem
bly consists of thermoswitch body, P/N 2450-040, with
coupling jack, P/N 2450-018, attached.
Cooling The dielectric coolant is chosen for its desirable dielectric
and thermal characteristics. Cooling of the load is accomplished by natural fluid and air convection currents. The
dielectric coolant carries the electrically generated heat
from the resistor to the walls of the cylindrical cooling
tank. This tank is encased in a set of radiating fins constructed from heavy gauge aluminum alloy and firmly
pressed onto the cylinder. The heat from the dielectric oil
is transferred to the surrounding air by the fins. The
Model 6732B uses 0.35 gallon (1.3 liter) of coolant, the
Model 6734B030 uses 0.9 gallon (3.4 liter), the Model
6735-300A uses 2.9 gallons (11 liter), the Model
6736/A/-030A uses 1.1 gallons (4.2 liter), and the Model
6737/A/-030A uses 0.9 gallon (3.4 liter) of coolant.
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Expansion of the coolant, caused by the rise in its tem
perature, is allowed for by means of a synthetic rubber
diaphragm (not visible) in the rear cover dome of the load
for the Models 6732B, 6734B, 6734B030, 6737A and
6737-030A. In addition, the Models 6737A and 6737-030A
are equipped with a cooling coil for circulating water that
will remove most of the generated heat from the dielectric
coolant. Models 6735-300A, 6737A and 6736-030A have a
spring loaded vent plug rather than a diaphragm for re
lieving the excess pressure caused by the coolant expan
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sion.
6
Principles of Operation
Schematic Diagram for Models 6734B030, 6736-030A, and 6737-030A
Figure 1
Off
M
25W
100W
500W
50 Ohm
Input
Note - Power ranges shown are for Model 6734B-030.
50 Ohm
Load
7
Principles of Operation
Schematic Diagram for Models 6732B, 6734B, 6735-300A, 6736A, and 6737A
Figure 2
Off
M
25W
100W
500W
50 Ohm
Input
Note - Power ranges shown are for Model 6734B.
8
50 Ohm
Load
Installation
Operate the load portion in the horizontal position only,
with the handle or vent plug on top. The only exceptions
are the Models 6737A and 6737-030A. When horizontally
mounted and without supplemental water cooling, these
loads will safely dissipate a maximum of 500 watts. Ver
tically mounted and without supplemental water cooling,
they will dissipate 200 watts. Vertically mounted, with
the RF connector down and with water cooling, they will
dissipate up to 2500 watts continuously.
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Mounting
Rectangle
6732B 5 1/8" (130.2 mm) 7 15/32" (189.7 mm)
6734B & 6734B-030 5 1/8" (1302 mm) 12 17/32" (318.3
6735-300A 4 ½" (114.3 mm) 20 23/32" (526.3
6736A & 6736-030A 5 1/8" (130.2 mm) 15" (381 mm)
6737A & 6737-030A 5 1/8" (130.2 mm) 12 17/32" (318.3
The front and rear fins are made extra thick and bent
outward 90 degrees to form mounting flanges. In each
model, the mounting flanges have 9/32 inch (7 mm) holes
near the corners to form a rectangle with the holes centered on the corners. The dimensions of the rectangle are
given below:
Width Length
mm)
mm)
mm)
WARNING
Before applying RF power to the Models 6735-300A,
6736-030A or 6736A be sure to remove the shipping
plug, P/N 2450-049 located near or on top of the
radiator. Replace the shipping plug with the supplied
breather vent plug, P/N 2450-094. This is important as
internal pressure build-up, caused by expansion of the
heated dielectric coolant, could cause damage to the
equipment and injury to the operator.
Installing
the Vent
Plug
The Models 6735-300A, 6736A and 6736-030A are sup
plied with special spring loaded vent plugs that are de
signed to open when the pressure developed by the
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9
Bird Model 6730B Series Termaline Wattmeter
heated coolant rises by more than a few pounds above at
mospheric pressure. By this means, the pressure is re
lieved while at the same time foreign materials are
prevented from entering the tank and contaminating the
dielectric coolant. When these wattmeters leave the fac
tory, the vent opening is sealed with a shipping plug
which is attached to the vent plug by a length of beaded
chain. Before putting the unit in operation, be sure to re
move the shipping plug and replace it with the vent plug.
Retain the shipping plug with its O-Ring for future use
should it become necessary to transport the load again.
Models 6734B030, 6736-030A and 6737-030A utilize a
special low frequency line section, P/N 6734-034, which
can also be ordered as an accessory to Models 6734B,
6736A and 6737A. To mount the 6734-034 in place, first
remove the existing line section. Do this by unscrewing
the dc cable from the voltmeter block. Next remove the
four screws from the corners of the flange that is bolted
to the face of the load portion. If the low frequency line
section is not already equipped with its own “QC” connector, then remove the connector from the existing line section. Do this by loosening the four screws from the
corners of the mounting flange and pull the connector
straight out. Install it on the low frequency line section
by carefully inserting the pin on the back end of the connector into the hole on the face of the line section. Then
press the connector into place. Return the four mounting
screws to fasten the connector in position. Now remount
the line section onto the load and fasten it in place with
its four mounting screws. Finally, reattach the dc cable
from the meter to the voltmeter block.
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Installing
the Thermo-
switch
10
On the Model 6735-300A, an overtemperature
thermoswitch, P/N 2450-056, is available as an accessory.
If ordered as part of the original equipment it is factory
installed. If ordered later it must be field installed; pro
ceed as follows:
Installation
Figure 3
Thermo-
switch
A
D
F
C
E
H
B
G
1. Stand the unit on its back end with the connector end
up. In this position there is no danger of coolant spillage.
2. Use a 9/16 allen wrench to remove the socket plug on
the front face of the radiator. Do this carefully to avoid
damaging the threads in the plug hole.
Connecting
the Thermo-
switch
3. Replace the plug with the thermoswitch. Use an acceptable pipe sealing compound, “Locktite with Teflon”
or equivalent, sparingly on the external threads only.
Do not use ordinary plumbers pipe dope as it will con
taminate the coolant! Observe closely for coolant leaks.
1. Unscrew the larger knurled ring nut (A) at the lower
end of the coupling jack assembly and pull it off the
thermoswitch jack (B). Unscrew the small knurled
cover fitting (C) from the base plug (D) of the connector
to release the base.
2. Thread the interlock wires through the clamp (E),
with washers (F) inside, and with its threaded fitting in
place. Service the interlock wire with short tips, use
spaghetti sleeves over wire ends if needed. Then se
curely solder the interlock leads to the lugs (G) of the
connector base. Note - Be sure that the larger captive
clamping nut (A) is in place over the base plug (D) with
the knurled end outward (towards the face).
3. Screw on the cover ring (C) first, then fasten the ca
ble clamp (E) in place and tighten the two yoke screws
11
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Bird Model 6730B Series Termaline Wattmeter
(H) on the cable. Push the plug back on the
thermoswitch and tighten the captive knurled connect
ing ring. Do not attempt to operate the equipment with
out interlocking it with the transmitter or RF source.
Locate the load portion to provide at least six inches of
free space around and above the unit. Place the load so
that the shortest possible cable length connects it to the
transmitting equipment.
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12
Chapter 3
Operating Instructions
Controls The only operating control is the range selector switch on
the lower right hand face of the meter unit. No adjust
ment or control settings are required.
Start-Up Connect the load to the transmitting equipment under
test with 50 ohm coaxial cable (RG-8A/U, RG-9/U,
RG-213/U or equal) equipped with a Male N type plug
(UG-21E/U or equal) which mates with the RF input con
nector of the load for Models 6732B, 6734B and
6734B-030. For Models 6735-300A, 6736A, 6736-030A,
6737A and 6737-030A use a cable equipped with a Male
LC type plug. After the transmitter has been connected to
the load, proceed according to the transmitter manufacturer’s instructions. When reconnecting the antenna, it
may be necessary to slightly adjust the transmitter due
to possible differences in VSWR between the load and the
antenna system.
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Normal
Operation
Each Termaline Wattmeter will continuously measure
and safely dissipate RF power up to its maximum rating.
To operate, set the range selector switch to the desired
power range and turn on the RF power source. The RF
power absorbed by the load portion will be displayed on
the meter. Read the power level from the scale that
matches the range set by the range selector switch. For
Models 6737A and 6737-030A set the water rate to at
least ½ gallon/minute (2 liter/minute).
WARNING
When the unit is used in the upper range of its power
capacity, the radiator will become hot - care should be
used in touching the equipment.
WARNING
Do not attempt to operate the Termaline Wattmeter for
prolonged periods at higher than rated load levels.
Damage to the equipment and injury to operator may
result.
13
Bird Model 6730B Series Termaline Wattmeter
Operation
Under
Emergency,
Adverse, or
Abnormal
Conditions
The loads of the Series 6700A/B Termaline Wattmeters
will withstand a temporary overload of up to 20 percent
above their nominal maximum rating. The overload
should be applied for no more than five to ten minutes.
Allow at least a half-hour of cooling thereafter before sub
jecting the unit to another overload. For Models 6737A
and 6737-030A, increase the water flow rate for extra
protection. Do not allow the water to reach the boiling
point. If it does, the RF power must be immediately de
creased and/or the water flow rate increased.
It should be understood that although the load portion
can accept a limited overload, the meter is restricted to
the amount of overranging acceptable. Disconnect the me
ter lead from the voltmeter to avoid damage.
Shutdown It is not possible to cut off the flow of RF power into the
load except by turning off the transmitter or RF source.
Turning the range selector switch to OFF merely deactivates the meter without affecting the load.
WARNING
Never attempt to disconnect any RF equipment from
the transmission line while RF power is being applied.
Leaking RF energy is a potential health hazard.
Emergency
Turn off the source of RF power.
Shutdown
-
-
-
14
Chapter 5
Troubleshooting
Maintenance
For corrections requiring repair or replacement of compo
nents, refer to the appropriate section for your specific
model.
Problem Possible Cause Remedy
Coolant oil leaking
around clamping band
or radiator housing
Excessive overheating
of the radiator
High or low dc resis
tance values per para
Incorrect power read
ing
-
Clamping bands not
tight
Faulty O-Ring (front) Replace O-ring
Faulty diaphragm
(rear)
Transmitter power too
high
Coolant oil level too
low
Accumulation of dirt
on cooling fins
Faulty RF section
assembly
Faulty RF connector Replace RF connector
Loose RF connector Tighten with a screw
Faulty RF section
assembly
-
Defective diode Return to authorized
Loose meter cable Tighten cable
Tighten slightly with a
screwdriver
Replace diaphragm
Reduce transmitter
power
Add more coolant oil
to the radiator
Clean the fins
Replace RF section
assembly
driver
Replace RF section
assembly
service facility for re
placement and calibra
tion
connector
-
-
-
-
15
Bird Model 6730B Series Termaline Wattmeter
Cleaning
Outside
Surfaces
Radiator If any portions of the radiator are corroded or rusted,
The outside surface of these wattmeters should be wiped
free of dust and dirt when necessary. The principle main
tenance required by the operator will be to periodically
wipe the accumulated dust and lint off of the radiator
fins. Excessive dust and lint on the cooling fins will inter
fere with the efficient dissipation of heat. If the Teflon in
sulator or metallic contact surfaces of the connector
should become dirty or grimy, wipe them off with a soft
cloth. Use a contact cleaner that is self-drying and
nonresidue-forming to clean the inaccessible internal
parts.
clean the areas with a fine flint sandpaper, and then
touch them up with grey enamel.
Inspection
With the rugged and simple construction of the Termaline
Wattmeters inspection will only be necessary at six
month intervals. Check for coolant oil seepage around the
radiator tank, particularly at the front and back around
the underside of the clamping band. If leakage is
observed use the troubleshooting table and check the
tightness of the clamping screw and the fasteners around
the front cylinder.
Preventive Maintenance
-
-
-
16
Preventive maintenance is limited to cleaning the equip
ment, particularly the radiator fins. It is important to
maintain the heat transfer efficiency of the cooling fins.
Also, occasionally check the coolant level in the radiator
tank.
-
RF Assembly Test
The electrical condition of the load resistor itself may be
ascertained generally from its dc resistance at room tem
perature. It must be remembered that VSWR and RF im
pedance are the prime requisites of a good dummy load,
however, occasionally checking the dc resistance will offer
an indication of a failing load.
Normally the dc resistance of the load will be a nominal
50 ohms. Stabilization of the resistive film or temperature
can cause a change in the dc resistance. Always check
-
-
Maintenance
the load when its temperature is between 20 and 25 de
-
grees Celsius.
Check and record the dc resistance value of the load be
fore it is put into service. Use a resistance bridge or ohm
meter with an accuracy of 1 percent or better at 50 ohms
for this purpose.
If the wattmeter is used frequently, daily to weekly, it is
recommended to check the dc resistance on a monthly
schedule. If the wattmeter is used more infrequently you
may want to set up a six month to yearly schedule ac
cordingly. If there is no change or even a slight change in
dc resistance there is no cause for alarm. A change
greater than two ohms could be an indication of a failing
load.
These tests are by no means a necessity to the operation
of the wattmeter but merely guidelines for the users information and advisement.
Checking the wattmeter accuracy consists mainly of comparing its reading with the readings of similar wattmeters. If other wattmeters are not conveniently available
then return the instrument to the factory for
recalibration. Special calibration and calibration data can
be provided at an additional cost. Consult the factory for
details.
-
Connector
RF
Disassembly
There are no special techniques required for the repair or
replacement of components in these Termaline Wattme
ters. A screwdriver and a small wrench are the only tools
needed. The paragraphs below outline component re
moval.
The connector is a “Quick-Change” design which permits
easy interchange with the use of only a screwdriver. This
process does not interfere with the essential coaxial conti
nuity of the load resistor RF input or the coolant oil seal.
For replacement, proceed as follows:
1. Remove the four 8-32 x 5/16 round head machine
screws from the corners of the RF connector.
2. Pull the connector straight out of its socket.
-
-
-
17
Bird Model 6730B Series Termaline Wattmeter
Diaphragm
and Coolant
Oil
Remove the diaphragm to replace or examine the coolant
oil. For replacement of the diaphragm and coolant oil fol
low the steps below for the appropriate model.
CAUTION
Do not replace coolant with anything but the specified
fluid. The inner shell of the resistor housing is
contoured to the dielectric properties of this fluid. The
use of any other type of coolant will affect the electrical
performance of the load.
Models 6732B, 6734B, 6734B-030, 6737A and 6737-030A
1. Stand the load vertically, with the back end up.
2. Loosen the clamp screw until the clamp band is
released.
3. Remove the diaphragm cover and lift the diaphragm from the back end of the radiator tank.
Inspect the diaphragm. If it is no longer soft and
pliable or shows signs of surface cracks it should
be replaced.
4. The coolant oil level should be about one inch below the top of the radiator cylinder. The coolant
should be clear to a light yellow color; if not, it
may be contaminated and should be replaced.
-
18
Model 6735-300A (No Diaphragm);
1. Place the unit on its back, connector up, by lift
ing the radiator front. Do it carefully keeping the
topside always face up. The vent hole is so posi
tioned on the topside that when the unit is up
ended in this manner, the coolant level will
remain just below the vent hole and not spill out.
2. Loosen the 10-32 x 1-1/2 inch screw on the
clamping band.
3. Remove the clamping band and lift the load re
sistor assembly out of the tank. Allow the excess
coolant to drip back into the tank before laying
the assembly aside.
4. At ambient room temperature, the coolant level
should be 4-3/4 inch (120 mm) below the top sur
face of the load resistor assembly mounting ring.
The tank is factory filled to this level with 2.9
-
-
-
-
-
Maintenance
gallons (11 liter) of a specially selected dielectric
fluid (P/N 5-030). The level of the fluid should re
main constant, even after prolonged usage, under
normal operating conditions.
Models 6736A and 6736-030A;
1. To check the coolant level, remove the vent plug
from the top rear surface of the expansion tank.
2. Unscrew the plug with a 3/4 wrench. The coolant
level at room temperature should be no more
than 1/8 inch above the bottom surface of the ex
pansion tank. This can be verified by carefully
lifting the load at its front end and noting the
presence of coolant on the bottom surface. The
unit is factory filled to the proper level with 1.1
gallons (4.2 liter) of a specially selected dielectric
fluid, P/N 5-1070.
3. To replace the diaphragm, stand the load on its
front end with the connector facing down, if the
coolant has not been drained previously.
4. Unscrew the four 10-32 truss head screws at the
corners of the guard cover, P/N 2430-078, and remove the guard box.
-
-
RF Load
Resistor
5. Unscrew the tube nut from the tank nozzle and
pull it free.
6. Remove the clamp screw from the bottom of the
V-band clamp, the same type as on the front
side, and remove the clamp. The rear cover, in
cluding the attached escape tube with its captive
nut, P/N 2430-088, and the diaphragm seal, P/N
2430-089, can now be easily removed.
7. Inspect the diaphragm seal. If it is not soft, pli
able and free from surface cracks or other signs
of deterioration, replace it (P/N 2430-015). At this
point, if the coolant P/N 5-1070, shows signs of
contaminations; i.e., not a crystal clear white
color, replace it also.
Models 6732B, 6734B, 6734B-030, 6737A and 6737-030A;
1. Stand the load vertically, connector end up, and
brace it to avoid tipping over.
-
19
Bird Model 6730B Series Termaline Wattmeter
2. Loosen the clamp screw until the clamping band
is released.
3. Hold the load assembly by the RF connector and
pull the assembly slowly out of the radiator tank
allowing the excess coolant to drain back into the
radiator.
4. Inspect the O-Ring seal which is located just in
side the mounting flange of the radiator assem
bly. Do not reuse the O-Ring if it is no longer
soft and pliable or shows signs of surface cracks.
5. Replace it with P/N 5-230 for Model 6732B and
P/N 8110-039 for Models 6734B, 6734B-030,
6737A and 6737-030A.
Model 6735-300A;
1. Place the unit on its back, connector up, by lifting the radiator front. Do it carefully keeping the
topside always facing up. The vent hole is so positioned on the topside that when the unit is upended in this manner, the coolant level will
remain just below the vent hole and not spill out.
2. Loosen the 10-32 x 1-1/2 inch screw on the
clamping band.
3. Remove the clamping band and lift the load resistor assembly out of the tank. Allow the excess
coolant to drip back into the tank before laying
the assembly aside.
4. At ambient room temperature, the coolant level
should be 4-3/4 inch (120 mm) below the top sur
face of the load resistor assembly mounting ring.
The tank is factory filled to this level with 2.9
gallons (11 liter) of a specially selected dielectric
fluid (P/N 5-030). The level of the fluid should re
main constant, even after prolonged usage, under
normal operating conditions.
-
-
-
-
20
5. Inspect the O-Ring seal. It should be free of
twists and positioned evenly all around the bev
eled flange of the resistor housing. The O-Ring
should be soft and pliable and show no signs of
surface cracks. If it has deteriorated, replace it
with P/N 8110-039.
-
Maintenance
Models 6736A and 6736-030A;
1. Replace the vent plug, P/N 2450-094, with the
shipping plug, P/N 2450-049. Make sure to use
the O-Ring seal to avoid leakage.
Connector
RF
Diaphragm
and Coolant
Oil
2. Stand the unit on its back end, with the connec
tor up, and brace it if necessary to prevent it
from tipping over.
3. Loosen the 10-32 x 1-1/2 inch screw on the clamp
ing band and remove the clamping band.
4. Grasping the RF connector, slowly lift the load re
sistor assembly out of the radiator tank allowing
the excess coolant to drip back in.
5. Inspect the O-Ring seal to be sure it is free of
twists and positioned evenly around the beveled
flange of the resistor housing. If the O-Ring is
not soft and pliable or shows signs of surface
cracks, replace it with P/N 5-230.
Assembly
To install a new connector, reverse the disassembly procedure. Be sure that the projecting center pin on the
connector is carefully engaged and properly seated
within the mating socket of the load resistor input before pressing it home.
Models 6732B, 6734B, 6734B-030, 6737A and 6737-030A.
1. Put the diaphragm back in place on the radiator
tank.
-
-
-
2. Press the cuplike swelling in the center of the di
aphragm down into the tank to remove the
trapped air bubble. To allow the air to escape,
pry the diaphragm away from the edge of the
tank.
3. Through the same opening add more oil, if neces
sary, until the oil level is flush with the top of
the tank.
4. Replace the diaphragm cover and the clamping
band.
5. Tighten the clamping screw.
-
-
21
Bird Model 6730B Series Termaline Wattmeter
Model 6735-300A
1. Replace the load assembly and the clamping
band.
2. Tighten the clamping screw.
3. Carefully lower the load back onto its feet.
Model 6736A and 6736-030A
Reverse disassembly procedure.
RF Load
Resistor
Load
Portion
Meter
Portion
Low
Frequency
Line
Section
Reverse disassembly procedure.
Storage
No special preparations for storage are necessary other
than to cover the equipment to keep out dust and dirt.
Store these units in a dry and dust-free environment
where the ambient temperature will remain within the
-40°C to +45°C (-40F to +113F) working range of the
wattmeter
Shipment
Wrap the RF connector with padding and tape the padding securely in place. Pack and brace the load in a suitable shipping container; a corrugated paper box should
suffice. It is not necessary to remove the dielectric coolant
before shipping. However, for Models 6735-300A, 6736A
and 6736-030A replace the vent plug with the shipping
plug; see page 10 for instructions.
Disconnect the dc cable from the voltmeter block and
then wrap the meter with padding and tape securely in
place. The meter can then be shipped in the same con
tainer as the load portion.
If the low frequency line section is part of the equipment
as an extra accessory, wrap and tape it securely in pad
ding before putting it in the container with the load and
meter.
-
-
22
Maintenance
Customer Service
Any maintenance or service procedure beyond the scope
of those provided in this section should be referred to a
qualified service center. Bird Electronic Corporation main
tains complete repair and calibration facilities at the fol
lowing addresses:
Service Group
U.S.A. Sales and Manufacturing
Bird Electronic Corporation
30303 Aurora Road
Cleveland (Solon), Ohio 44139-2794
Phone: (440) 248-1200
Fax: (440) 248-5426
Sales Offices
European Sales Office
Bird Electronic Corporation
Berkhamsted House
121 High Street
Berkhamsted
Hertfordshire
HP4 2DJ England
Phone: 44 1 442 870097
Fax: 44 1 442 870148
-
-
Pan Asian Sales Office
Bird Electronic Ltd.
3A Unit 6 Tyrwhitt Road
Singapore 0820
Phone: 65 299 2537
Fax: 65 299 8509
23
Bird Model 6730B Series Termaline Wattmeter
Replacement
Parts List
Series 6730B
Item Qty. Description Part Number
1
2
3
4
5
1
1
1
1
1
Rotary switch 6735-008
“QC” connector *See Below
DC cable assembly 4220-097-25
DC connector shorting plug 7500-268
Range switching knob 4110-016
MODELS 6732B/34B/35-300A/36A/37A
6
7
1
1
Voltmeter cartridge assembly 6735-004
Diode 5-1180
MODELS 6734B-030/36-030A/37-030A
8
9
10
1
1
1
Input RF section assembly 6734-034
Voltmeter assembly 6735-004
Diode 5-1180
MODEL 6732B
11
12
13
14
15
16
17
18
19
1
1
1
0.35 gallon
(1.3 liters)
1
1
1
1
1
Meter 2080A067
Cooling radiator 2440-015
RF section assembly 8141-002
Coolant (DC-200) 5-1070-2
(1 Gallon Container)
Clamp band assembly 2430-055
O-Ring seal 5-230
Diaphragm 2430-015
Diaphragm Cover 2430-148
Radiator handle 2400-017
MODELS 6734B and 6734B-030
20
21
22
23
24
25
26
1
1
1
0.9 gallon (3.4
liters)
1
1
1
Meter 2080A068
Radiator assembly 2430-050
RF section assembly 8205-002
Coolant (dielectric) 5-030-3
Diaphragm 2430-015
Diaphragm cover 2430-148
Clamp band kit 2430-055
24
(1 Gallon Container)
Maintenance
Item Qty. Description Part Number
27
28
29
1
1
1
O-Ring seal 8110-039
Back cover assembly 6732-004
Radiator handle 2430-028
MODEL 6735-300A
30
31
32
33
34
35
36
37
1
1
1
1
1
1
2
1
Meter 2150-263
RF load resistor 8205-002
O-Ring, RF section 8110-039
Clamping band assembly 2430-055
Breather vent plug 2450-094
Shipping plug 2450-049
O-Ring, vent/shipping plug 5-504
Thermoswitch assembly,
overtemperature
2.9 gallon
38
39
(11 liters)
1
Coolant (dielectric) 5-030-3
(1 Gallon Container)
Radiator assembly 2450-301
MODELS 6736A and 6736-030A
40
41
42
43
44
45
46
47
48
49
50
51
1
1
1
1
1
2
1.1 gallon (4.1
liters)
1
1
2
1
1
Meter 2150-267
RF section assembly 8890-050
O-Ring, RF section 5-230
Diaphragm cover guard 2430-088
Diaphragm seal 2430-089
Clamping band assembly 2430-055
Coolant (dielectric) 5-1070-2
(1 Gallon Container)
Breather vent plug 2450-094
Shipping plug 2450-049
O-Ring, vent/shipping plug 5-504
Radiator 2430-123
Expansion tank (part of radi
-
ator)
52
53
1
1
Radiator handle 2430-028
Chain assembly 8180-094
2450-056
2430-080
MODELS 6737A and 6737-030A
54
55
56
1
1
1
Meter 2150-265
Radiator assembly 2430-050
RF section assembly 8230-002-2
25
Bird Model 6730B Series Termaline Wattmeter
Item Qty. Description Part Number
0.9 gallon (3.4
57
58
59
60
61
62
liters)
1
1
2
1
1
Coolant (dielectric) 5-303-3
(1 Gallon Container)
Diaphragm 2430-015
Diaphragm cover 2430-148
Clamp band assembly 2430-055
O-Ring RF assembly 8110-039
Radiator handle 2430-028
* Available QC Type Connectors
N-Female
†
4240-062 LT-Female 4240-018
N-Male 4240-063 LT-Male 4240-012
HN-Female 4240-268 C-Female 4240-100
HN-Male 4240-278 C-Male 4240-110
LC-Female
‡
4240-031 UHF-Female 4240-050
LC-Male 4240-025 UHF-Male 4240-179
7/8" EIA Air
4240-002
Line
†
Standard for Models 6532A/34A/-030
‡
Standard for Models 6735-300A, 6736A/36-030/37/37-030
26
DECLARATION OF CONFORMITY
Manufacturer: Bird Electronic Corporation
Product: Termaline Absorption Wattmeter
The undersigned hereby declares, on behalf of Bird Electronic Corporation of Cleveland,
Ohio, that the above-referenced product, to which this declaration relates, is in
conformity with the provisions of the following standards:.
1. European Standard EN 55011:1991-Emissions:Class B.
2. European Standard EN 50082-2:1992-Immunity; Residential,
These standards are in accordance with Council Directive 89/336/EEC , on
Electromagnetic Compatibility, as amended by Council Directive 92/31/EEC.
3. European Standard EN 61010-1:1993 - Safety, Group II.
This standard is in accordance with Council Directive 73/23/EEC and 93/68/EEC.
The technical documentation file required by this directive is maintained at the corporate
headquarters of Bird Electronic Corporation, 30303 Aurora Road, Cleveland, Ohio.
If you are located in Europe and have any questions, please contact:
Bird Electronic Corporation
Berkhamsted House
121 High Street
Berkhamsted Hertfordshire
HP4 2DJ England
Phone: (44) (1) 442 870097
Fax: (44) (1) 442 870148
30303 Aurora Road
Cleveland, Ohio 44139-2794
Models: 6732B 6736A
6734B 6736-030A
6734B030 6737A
6735-300A 6737-030A
Commercial, and Light Industrial.
Form No. 921-6730SCE
Ken DeVore
Q.A./Metrology Manager
Bird Electronic Corporation
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