Crown FM100 User`s manual

Crown FM100 User`s manual
FM2000A
Amplifier Package
User's Manual
©2005 Crown Broadcast, a division of International Radio and Electronics, Inc.
25166 Leer Drive, Elkhart, Indiana, 46514-5425 U.S.A.
(574) 262-8900
i
Revision Control
Revision
Print Date
Initial Release (Rev. 0) 900415-1
November 1998
Second Printing 130319-1
November 1999
Third Printing
April 2002
Fourth Printing
May 2005
Important Notices
©2005, Crown Broadcast, a division of International Radio and Electronics, Inc.
All rights reserved. No part of this publication may be reproduced, transmitted,
transcribed, stored in a retrieval system, or translated into any language in any
form by any means without the written permission of Crown International, Inc.
Printed in U.S.A.
Crown attempts to provide information that is accurate, complete, and useful.
Should you find inadequacies in the text, please send your comments to the
following address:
International Radio and Electronics
25166 Leer Drive, P.O. Box 2000
Elkhart, Indiana, 46515-2000 U.S.A.
ii
Contents
Section 1—Getting Acquainted
1.1 Your Amplifier Package ..................................................................................... 1-2
1.2 Amplifier Package Specifications ...................................................................... 1-3
1.3 Safety Considerations ....................................................................................... 1-4
1.3.1 Dangers ........................................................................................................ 1-4
1.3.2 Warnings ...................................................................................................... 1-4
1.3.3 Cautions ....................................................................................................... 1-4
Section 2—Installation
2.1 Operating Environment ..................................................................................... 2–2
2.2 Tools Required .................................................................................................. 2–2
2.3 Unpacking ......................................................................................................... 2–2
2.4 Preinstallation ................................................................................................... 2–3
2.4.1 Power Amplifier Modules ............................................................................. 2–3
2.4.2 Hubble Twist Lock® Connector Wiring ........................................................ 2–4
2.5 Installation ........................................................................................................ 2–5
2.6 Remote I/O Connection ..................................................................................... 2–6
Section 3—Operation
3.1 Initial Power-up Procedures.............................................................................. 3–2
3.2 Power Switches ................................................................................................ 3–4
3.2.1 AC Input Circuit Breaker ............................................................................... 3–4
3.2.2 DC Power Switch .......................................................................................... 3–5
3.2.3 Interlock Switch ............................................................................................ 3–5
3.3 Digital Multimeter ............................................................................................. 3–6
3.4 Fault Indicators ................................................................................................. 3–7
3.5 Fuse Indicators ................................................................................................. 3–8
Section 4—Principles of Operation
4.1 PA2000 Power Amplifier ................................................................................... 4–2
4.1.1 Power Modules ............................................................................................ 4–2
4.1.2 Power Combiner Board ................................................................................ 4–2
4.1.3 Backplane Assembly ..................................................................................... 4–3
4.1.3.1
Backplane DC Interconnect Board ........................................................ 4–3
4.1.3.2
Input Divider Board ............................................................................... 4–3
4.1.3.3
Output Combiner Board ........................................................................ 4–3
4.1.4 Output Filter & Reflectometer ....................................................................... 4–3
4.1.5 Metering and Control Board ......................................................................... 4–4
4.1.6 DC Fuse and Power Distribution Board ........................................................ 4–4
4.1.7 Cooling Fans ................................................................................................. 4–4
iii
4.2 PS2000 Power Supply ...................................................................................... 4–5
4.2.1 AC Input Board ............................................................................................. 4–5
4.2.2 PFC (Power Factor Correcting) Switching Board .......................................... 4–5
4.2.3 DC Output Board .......................................................................................... 4–6
4.2.4 Cooling Fans ................................................................................................. 4–6
Section 5—Troubleshooting
5.1 Troubleshooting Flow Chart Analysis ................................................................ 5–2
5.2.1 In Ref (Input Drive Reference) ...................................................................... 5–3
5.2.2 SWR (Standing Wave Ratio) ........................................................................ 5–3
5.2.3 ALC (Automatic Level Control) ..................................................................... 5–3
5.2.4 Power Out .................................................................................................... 5–3
5.2 Digital Multimeter Parameters .......................................................................... 5–3
5.2.5 PA Temp ....................................................................................................... 5–4
5.2.6 PA Voltage .................................................................................................... 5–4
5.2.7 Tot Current ................................................................................................... 5–4
5.2.8 PA1–8 ........................................................................................................... 5–4
5.3 Fault Indicators ................................................................................................. 5–5
5.3.1 Antenna ........................................................................................................ 5–5
5.3.2 RF Drive ........................................................................................................ 5–5
5.3.3 PA Temp ....................................................................................................... 5–5
5.3.3.1
Potential Causes for Non-functioning Cooling Fans .............................. 5–5
5.3.4 PA DC ........................................................................................................... 5–6
5.3.5 Multiple Indicators........................................................................................ 5–6
Section 6—Reference Drawings
6.1 Views ................................................................................................................ 6–2
6.2 Diagrams and Schematics ................................................................................ 6–3
Section 7—Service and Support
7.1 Service .............................................................................................................. 7–2
7.2 24–Hour Support .............................................................................................. 7–2
7.3 Spare Parts ....................................................................................................... 7–2
Glossary
Index
iv
I
INFORMATION
Section 1—Getting Acquainted
This section provides a general description of the FM2000A
power amplifier system and introduces you to safety conventions
used within this document. Review this material before installing or operating the amplifier and power supply.
Getting Acquainted
1–1
I
1.1 Your Amplifier Package
The FM2000A is a highly efficient amplifier package designed to set a new standard
in FM transmitter design offering modularity, ease of use, and long-term reliability. The FM2000A package includes a PA2000 amplifier, PS2000 power supply, and
an FM2K accessory pack.
The PA2000 broadband amplifier requires no tuning and typically provides 80% RF
efficiency across the band. The PS2000 power supply is power factor corrected and
90% efficient. Modern MOSFET technology ensures high AC to RF efficiency
(better than 70% overall) and long-term reliability. The unmatched efficiency of
this power amplifier significantly improves your bottom line by providing cooler
operation and lower power costs.
These modular units are uniquely designed to be lightweight and compact for
convenient shipping, and require only seven RU spaces for installation. Installation is made simple with just three interconnections between the amplifier and
power supply. In addition, built-in digital metering and status indicator capabilities enable intuitive operation to further augment the user-friendly design.
Economic long-term reliability is ensured through our carefully engineered solidstate design. The PA2000 features four field-replaceable 500–watt power modules.
This power amplifier delivers 500 to over 2000 watts of RF power output. Use your
existing exciter or purchase the FM2000T which includes our award-winning
FM100 exciter for an unbeatable 2 kW transmitter package.
Metering
Fault
In Ref
SWR
ALC
Power Out
PA Temp
PA Voltage
Tot Current
PA1
PA2
PA5
PA6
PA3
PA4
PA7
PA8
Antenna
RF Drive
PA Temp
PA DC
Fuses
PA1
PA2
PA3
PA4
PA5
PA6
PA7
PA8
®
Power
I
O
®
Illustration 1–1 FM2000A Amplifier Package
1–2
FM2000A User’s Manual
1.2 Amplifier Package Specifications
RF Power Output:
200 to 2200 watts continuous with controlled
power adjust, with remote controlled power
capability
RF Drive Requirement:
50-70 watts for full output
RF Output Impedance:
50 watts (unbalanced)
Maximum SWR:
1.7:1 (With power foldback at high SWR)
Frequency Range:
87–108 MHz
RF Harmonics/Spurious Products: Better than –80 dB
Asynchronous AM S/N Ratio:
Better than 55 dB with 100% modulation @
400 Hz, no de-emphasis, no FM modulation
(typically > 60 dB)
Synchronous AM S/N Ratio:
Better than 55 dB with 100% modulation @
400 Hz, no de-emphasis, FM modulation = 75 kHz @ 400 Hz (typically > 60 dB)
Operating Environment:
Temperature Range:
Humidity Range:
0°–50°C at sea level
0–80% at 20°C, noncondensing
AC Power:
240 volts AC +10/-15%, 50–60 Hz
Power Consumption:
2800 watts at 2000 watts RF output typical
Power Factor:
.96 typical
Overall Efficiency:
70% typical
RF Output Connector:
7/8 inch EIA flange, 7–16 inch DIN optional
Power Amplifier Chassis:
7 x 17.25 x 23 inches (17.78 x 43.82 x
58.42 cm) exclusive of rack ears, but
inclusive of connectors
Power Supply Chassis:
5.25 x 17.25 x 23 inches
(13.34 x 43.82 x 58.42 cm)
exclusive of rack ears
Weight:
PA2000—57.5 pounds (26.1 kg)
RF PA Modules —8 pounds (3.6 kg) each
PS2000—43 pounds (19.5 kg)
Note: System performance is specified using Crown Broadcast
Model FM100 Exciter where applicable.
Getting Acquainted
1–3
I
1.3 Safety Considerations
Crown Broadcast assumes the responsibility for providing you a safe product and
safety guidelines during its use. “Safety” means protection to all individuals who
install, operate, and service the transmitter as well as protection of the transmitter
itself. To promote safety, we use standard hazard alert labeling on the product and
in this manual. Follow the associated guidelines to avoid potential hazard.
1.3.1 Dangers
DANGER represents the most severe hazard alert. Extreme bodily harm or death
will occur if DANGER guidelines are not followed.
1.3.2 Warnings
WARNING represents hazards which could result in severe injury or death.
1.3.3 Cautions
CAUTION indicates potential personal injury or equipment or property damage if
the associated guidelines are not followed. Particular cautions in this text also
indicate unauthorized radio-frequency operation.
Type of Hazard
WARNING
Severe shock hazard!
Pictorial Indication
of Hazard
Turn power off and
wait approximately 1
minute for capacitors
to discharge before
handling them.
Explanation
of Hazard
Illustration 1–3 Sample Hazard Alert
1–4
FM2000A User’s Manual
®
Section 2—Installation
This section provides important guidelines for installing your
power amplifier and power supply. Review this information carefully for proper installation.
Installation
2–1
2.1 Operating Environment
You can install the FM2000A amplifier system in a standard 19–inch component
rack or on a suitable surface such as a bench or desk. In any case, the area should
be as clean and well-ventillated as possible. The power supply must be installed
directly above or below the power amplifier (for the included dressed cables to
reach their respective connectors).
2.2 Tools Required
To install the power supply and power amplifier, you will need the following tools:
❑ Medium phillips screwdriver
❑ Medium flat-blade screwdriver
❑ Small flat-blade screwdriver
❑ 7/16–Inch wrench or nut driver
❑ ESD (Electrostatic Discharge) protection grounding strap and/or mat.
2.3 Unpacking
Before handling any exposed printed circuit boards, ground yourself with an
antistatic strap and/or mat.
CAUTION
Possible equipment damage!
Guard against electrostatic discharge
through electronic components.
The power amplifier, power supply, and two power amplifier modules are packed
and shipped in individual boxes because of their modular nature. (The FM2K
accessory kit is packed inside one of the two power amplifier module boxes.) For
added protection, both the PA2000 amplifier and PS2000 supply are packed in an
inner box and then placed inside an outer box with styrofoam protective corners in
both boxes. You will need to unpack a total of four boxes (plus two inner boxes).
Note: Save the boxes and packaging material that the individual
units are packed in should you need to return them for factory
service.
2–2
FM2000A User’s Manual
2.4 Preinstallation
2.4.1 Power Amplifier Modules
The PA2000 incorporates four power amplifiers (two each in two modules). Due to
possible damage during shipment, the power modules have been removed. Follow
these steps to install the modules:
1. Remove the front panel of the PA2000 (four screws).
2. Taking ESD precautions (see page 2–2), unpack the power modules and place
them on your work area with the circuit sides up.
Connector
Warning Label
Slide Rail
Illustration 2–1 Power Amplifier Module
3. The warning labels on the front of the modules should all be positioned to the
center of the chassis, also note the position of the connector on the modules
and in the chassis.
4. Insert the four power modules, using their slide rails, into the built in channels of the right-side cavity and two (upside down) in the left cavity as shown
below. Note that the connectors and warning labels are nearest the middle
wall or partition of the PA2000.
Module A
(amps 1 & 2)
Module B
(amps 3 & 4)
Module C
(amps 5 & 6)
Module D
(amps 7 & 8)
Middle Partition
Illustration 2–2 Power Amplifier Module Placement
5. Be sure the modules are pushed in completely so that the connector makes
proper contact.
6. Replace the front panel of the PA2000.
Installation
2–3
2.4.2 Hubble Twist Lock® Connector Wiring
Prepare the wiring for the Hubble Twist-Lock® connector in the following manner
before connecting to your AC power source:
1. Use round cord with a diameter of 0.385–0.780 inches (10–20 mm), Type SJ
12/3 – 10/3; Type S 16/3 – 10/3.
2. Select conductor size from your National Electrical Code®.
3. Slide the cover onto the cord. Remove insulation from cable and conductors
as shown in Illustration 2–3. Do not tin conductors.
1 Inch
(25 mm)
5/8 Inch
(16 mm)
Illustration 2–3 Cover, Cable & Conductors
4. Loosen terminal screws. Insert conductors fully into proper terminals according to the table below. Take caution that there are no stray wire strands.
Terminal
Conductor
Green Hex Head Screw
Equipment grounding conductor
(green or green/yellow)
Brass Screw
Hot circuit conductor, 240 VAC
(NOT white, NOT green)
Brass/Black Screw
Hot circuit conductor, 240 VAC
(NOT white, NOT green)
5. Tighten terminal screws to 18 pound•inches (2.1 N•m) of torque.
6. Tighten assembly screws to 10 pound•inches (1.1 N•m) of torque.
7. Tighten cord clamp screws to 10 pound•inches (1.1 N•m) of torque.
WARNING
Possible Electric Shock Hazard!
Do not connect AC source until all
other connections are made and
installation is complete.
2–4
FM2000A User’s Manual
2.5 Installation
1. Mount the units in an appropriate 19–inch wide cabinet. The power supply
must be installed directly below the power amplifier for the included cables
to reach their respective connectors (see illustration 2–4 below).
Note: The PS2000 weighs approximately 43 pounds (19.5 kg); the
PA2000, approximately 57.5 pounds (26.1). Use help to install.
2. Ensure that the PS2000 power switch is off, the circuit breakers of the 240
VAC source on the back panel are off, and the AC connector is not plugged in.
3. Install the exciter source (such as a Crown Broadcast FM100) according to its
instructions.
4. Connect the RF input cable from the exciter source to the N connector on the
back of the PA2000.
5. Connect the RF output cable (from the antenna) to the 7/8 EIA or 7-16 DIN
connector on the back of the PA2000.
6. Connect one end of the supplied control cable to the 9–pin D-sub connector
on the PA2000.
7. Connect the other end of the control cable to the 9–pin D-sub connector on
the PS2000.
+ DC Input
RF Monitor
(Optional Connection)
RF Input
Ground Screws
DC Input
Air Intakes/Filters
PA2000
Remote I/O
RF Output
Control
Circuit Breakers
+ DC Output
OFF
Fans
OFF
Power
Control
DC Output
PS2000
Air Exhaust Vents
240 VAC IN
Illustration 2–4 Rear Panel Connections
Installation
2–5
8. Using the supplied connector, tie together pins 6 and 7 of the Remote I/O
connector. The amplifier will not operate without this connection or a
remote switch on these pins. (See Section 2.6 for Remote I/O connection.)
9. If monitoring of the output signal is desired, connect the RF monitor cable to
the BNC connector on the PA2000.
10. Connect the DC input/output cables between the PA2000 and the PS2000 as
illustrated (Illustration 2–4). The connector end with the ground lead connects to the PA2000. Be sure to attach the ground leads as indicated.
Note: The power lead shield is only grounded at the PA chassis.
11. Install the covers over the DC terminals of the PA2000 and the PS2000 using
hardware form the hardware kit (1/4–inch X 6–32 bolts with lock washers).
12. Connect to your AC power source by inserting the Hubble Twist-Lock connector into the female Hubble connector on the PS2000 and turn to the right
until the connection locks.
2.6 Remote I/O Connection
The Remote I/O Connector on the back of the PA2000 allows remote control and
monitoring of Certain transmitter functions. There are three basic control functions—AC on/off, RF power level adjustment, and RF down/off.
The AC power on/off remote control function, available at pin 7 of the Remote I/O
Connector, turns DC power to the PA on when the pin is grounded.
The RF power level adjustment remote control function has an internal maximum
limit set on the Metering and Control Board. The Local Power Adjust (R62) sets
the maximum limit of RF power output. The limit is set by placing the Remote/
Local switch (SW5) in the LOCAL position and adjusting the Local Power Adjust to
your desired maximum limit (see illustrations 2–5 and 2–6). However, for any
remote operation to work, the Remote/Local slide switch must be in the REMOTE
position. Then the on-board remote RAISE and LOWER push buttons and any
external remote switches attached to pins 4 and 15 of the I/O Connector can adjust
+5V
R62
LOCAL
POWER
ADJUST
MAXIMUM
MINIMUM
REMOTE
RAISE POWER
Pin 4
Remote I/O Conn.
SW3
RAISE
ElectroControl
Circuit
LOCAL
SW5
REMOTE
REMOTE
LOWER POWER
Pin 15
Remote I/O Conn.
TANSMITTER
CONTROL
SW4
LOWER
Illustration 2–5 Local and Remote Functions
2–6
FM2000A User’s Manual
the level up to that limit and down to zero. When a specific output power level is
set, the Metering and Control Board controls and maintains the setting to keep the
power constant. The location of the Local Power Adjust (R62), the on-board Raise
and Lower switches (SW3 & SW4), and the Local/Remote slide switch (SW5) are
shown below.
Local/Remote
Slide Switch
On-board Remote
Power Adjust
Buttons
Local Power Adjust
Pot
Illustration 2–6 On-board Remote Power & Related Controls
Another remote control function, available at pin 5 of the Remote I/O Connector,
turns RF down/off. Connecting this pin to ground through a resistor allows the
RF power output level of the amplifier to be reduced below the internal limit set by
the Local Power Adjust pot or the remote Raise/Lower settings. However, some
drive power, less than one watt, may still be present at the antenna. Depending on
the resistor used, this pin can serve as a control for optional low power operation.
The remaining remote functions are for monitoring the various parameters
of the PA2000. They are either buffered metering outputs, direct reading, or
latched high/low indications. Further details of these functions are described in
the pin-out table on page 2–8.
Note: If Remote I/O controls are not used, tie pin 7 to pin 6 (GND.).
For remote I/O (Input/Output) connection, connect your remote I/O cable from
your remote control location to the 25–pin (female) D-sub connector on the back
panel of the PA2000. The I/O Connector on the power amplifier is described in the
following diagram:
13
25
1
14
Illustration 2–7 Remote I/O connector (back panel view)
The Remote I/O Connector Pinout Table on the next page summarizes the Remote
I/O pin connections.
Installation
2–7
Pin #
Function
1
PA#8 Current Monitor (a buffered metering output with 1 V = 2 A)
2
PA#7 Current Monitor (a buffered metering output with 1 V = 2 A)
3
Ground
4
Remote RAISE Power (a momentary switch, on this pin, when held low will
raise the power level 10 watts every 0.5 seconds)
5
Remote RF Power Control (a resistor to ground on this pin reduces RF
power output level below internal limits. See Section 2.6, page 2–7)
6
Ground
7
Remote AC Power On (a latching switch, on this pin, when held low will turn
the AC power supply on)
8
Fault Summary (the voltage from this pin goes to +5 V if any fault occurs and
drops below 2V when the fault goes away)
9
Ground
10
ALC (the voltage from this pin is a direct reading of automatic level control
voltage, not buffered)
11
PA Temperature (a buffered metering output with 1 V = 20° C)
12
SWR (a buffered metering output with a calculated reading of standing wave
ratio in VDC)
13
RF Output Power (a buffered metering output with a calculated reading of
output power of 1 V = 1000 W)
14
Input Power Reference (a buffered metering output with a DC voltage
representing input power)
15
Remote LOWER Power (a momentary switch, on this pin, when held low will
lower the power level 10 watts every 0.5 seconds)
16
PA#6 Current Monitor (a buffered metering output with 1 V = 2 A)
17
PA#5 Current Monitor (a buffered metering output with 1 V = 2 A)
18
Ground
19
PA#4 Current Monitor (a buffered metering output with 1 V = 2 A)
20
PA#3 Current Monitor (a buffered metering output with 1 V = 2 A)
21
Ground
22
PA#2 Current Monitor (a buffered metering output with 1 V = 2 A)
23
PA#1 Current Monitor (a buffered metering output with 1 V = 2 A)
24
PA Total Current Monitor (a buffered metering output with 1 V = 20 A)
25
PA Volts (a buffered metering output with 1 V = 10 V)
Note: PA = Power Amplifier
Remote I/O Connector Pinout Table
2–8
FM2000A User’s Manual
Section 3—Operation
This section provides general operating parameters of your
power amplifier system and a detailed description of the front
panel display.
Operation
3–1
3.1 Initial Power-up Procedures
These steps summarize the operating procedures you should use for the initial
operation of the power amplifier and power supply of the FM2000A.
1. Ensure that the external remote control unit is properly connected (See
Section 2.6 and the pin-out description table on page 2–8 for proper pin
configuration). If not using a remote control unit, pin 7 must be tied to
ground pin 6.
2. Connect Antenna.
3. If using an external remote control, enable the power supply via the remote
I/O connector.
4. Turn on (set to up) the AC input circuit breaker located on the rear panel of
the power supply (do not turn on the front panel power switch yet).
Outputs to
PA1000
AC Input
Circuit Breaker
Fan
Circuit Breaker
+ DC Output
OFF
OFF
Fans
Power
Control
DC Output
PS2000
Air Exhaust Vents
240 VAC IN
Illustration 3–1 PS2000 Back Panel Functions
5. Turn on the exciter (a Crown FM100 or equivalent) and adjust its RF power
output level until the In Reference (In Ref) voltage, as indicated on the PA2000
front panel Digital Multimeter, is between 0.8 and 1.2 volts. This is not a drive
dependent amplifier; therefore drive must be at a constant level regardless of
main output power.
Note: The unit will not operate until the exciter is active
and produces sufficient drive.
3–2
FM2000A User’s Manual
6. Before power-up, place the Local/Remote switch (located on the Metering &
Control board behind the front panel) in the Local position and adjust the
output power limit to the mid-level position using the Local Power Adjust,
also on the Metering & Control board (see Illustration 3–2 below). The unit is
normally shipped with this setting. See Section 2.6 for setting up remote
operation and using the on-board remote buttons and other controls.
Local/Remote
Slide Switch
On-board Remote
Power Adjust
Buttons
Local Power Adjust
Pot
Illustration 3–2 Local Power Adjust and Other Controls
7. Turn on the main power switch located on the front panel of the power supply.
(The unit typically takes 30 seconds to power up.)
Air Intakes/Filters
Power
I
O
®
Power Switch
Illustration 3–3 PS2000 Front Panel Functions
8. Check the PA2000 parameters with the Digital Multimeter for a current (Tot
Current) of 42 to 48 amps and a voltage (PA Voltage) of 32 to 36 volts. If
parameters are within range, increase the Local Power Adjust to the maximum
level of desired operation.
Note: The Local Power Adjust pot is unconventional (CW lowers power).
Operation
3–3
9. Place the Local/Remote switch (see Illustration 3–2) in the Remote position
and, using an external remote control unit connected to the Remote I/O
connector or the on-board remote Raise/Lower buttons, adjust the PA2000 to
the maximum power set by the Local Power Adjust. (This prevents adjusting
to higher than permitted power levels.)
10. Verify that the following conditions are present as indicated by the PA2000’s
Digital Multimeter:
a. In Ref—Should read between 0.4 and 0.8 volts (0.5 nominal, dependent
upon power input level).
b. SWR—Should read 1.05 to 1.5.
c. ALC—Should read between 4.00 and 6.00 volts for 2.2 kW output (less
for lower output or danger conditions, i.e. high SWR).
d. Power Out—Should read 2.20 for 2.2 kW output.
e. PA Temp—Should read 35 to 50°C with ambient temperature of 25°C.
The remainder of this section describes the functions of the front and rear panel
indicators and switches of the PA2000 and PS2000.
3.2 Power Switches
3.2.1 AC Input Circuit Breaker
The PS2000 supplies power to the PA2000 by converting single-phase 220/240 VAC
into 50 VDC. The PS2000 is protected by a 20 A, double-pole circuit breaker
located on the rear panel. This AC input circuit breaker must be in the “up”
position (as shown below) for operation.
AC Input
Circuit Breaker
ON
ON
Fans
Power
Control
240 VAC IN
Illustration 3–4 AC Input Circuit Breaker
3–4
FM2000A User’s Manual
3.2.2 DC Power Switch
The main on/off power switch located on the front panel of the power supply
controls high voltage output. (The control circuit activates this voltage.)
Power
I
O
®
Power Switch
Illustration 3–5 DC Power Switch
3.2.3 Interlock Switch
This switch is located on the fan mounting bracket in the power supply. When the
top cover of the power supply is removed, the Interlock Switch interrupts the power
supply control circuit disabling the high and low voltage supplies.
WARNING
Lethal voltages are still present on the AC Input Board !
So, handle with care.
Interlock Switch
Illustration 3–6 Interlock Switch
Operation
3–5
3.3 Digital Multimeter
The 3–digit numeric display in the upper left corner of the front panel provides
information on the amplifier’s operation. Use the “up” and “down” push-buttons to
select one of the following parameters as indicated by a green LED.
Multimeter
Metering Selection Buttons
Metering Indicators
Metering
Fault
In Ref
SWR
ALC
Power Out
PA Temp
PA Voltage
Tot Current
PA1
PA2
PA5
PA6
PA3
PA4
PA7
PA8
Antenna
RF Drive
PA Temp
PA DC
PA1
PA2
PA3
PA4
®
Illustration 3–7 Digital Multimeter
In Ref—Input reference is a relative voltage level used to determine input RF
power level. This varies between frequency of operation and input power level.
SWR—Direct reading of the antenna Standing-Wave Ratio (the ratio of the actual
load impedance to the desired 50 ohm load impedance).
ALC—Automatic level control is DC gain control bias used to regulate PA supply
voltage. With the PA power supply at full output voltage, ALC will read about 6.0
volts. When the RF output is being regulated by the RF power control circuit, this
voltage will be reduced, typically reading 5.0 to 6.0 volts. The ALC voltage will be
reduced during PA DC overcurrent, SWR, or overtemperature conditions.
Power Out—Actually reads RF voltage squared, so the accuracy can be affected by
SWR. Tolerance of ± 10% is normal. For exact set-up on site, an external power
meter is recommended.
PA Temp—Highest temperature of all individual RF power amplifier heatsinks in
degrees C.
PA Voltage—Supply voltage of the RF power amplifier.
Tot Current—Sum total current of all individual RF power amplifiers in amperes.
PA1–8—Individual RF amplifier current reading in amperes.
3–6
FM2000A User’s Manual
3.4 Fault Indicators
Faults are indicated by illuminated red LED’s when the following occurs:
Antenna—Load SWR exceeds 1.5:1. ALC voltage is reduced to limit the reflected
RF power.
RF Drive—Lack of or insufficient RF drive. If the RF drive fault LED is lit, input
drive must be increased. To achieve full output power, 70–80 watts of input drive is
required.
CAUTION
Possible equipment damage!
Do not exceed 80 watts of input drive.
Damage to the PA2000 will result if
this level is exceeded.
PA Temp—PA heatsink temperature is greater than 75°C (power foldback will begin
at this point).
PA DC—Power supply current for the PA (power amplifier) is at the preset limit, or
there is a difference of more than 2.5 amps in current between the individual PAs.
When this indicator is on ALC, the voltage is reduced automatically which holds the
supply current to the preset limit.
Fault Indicators
Metering
Fault
In Ref
SWR
ALC
Power Out
PA Temp
PA Voltage
Tot Current
PA1
PA2
PA5
PA6
PA3
PA4
PA7
PA8
Antenna
RF Drive
PA Temp
PA DC
Fuses
PA1
PA2
PA3
PA4
PA5
PA6
PA7
PA8
®
Illustration 3–8 Fault Indicators
Operation
3–7
3.5 Fuse Indicators
The PA2000 consists of four field-replacable power modules with two amplifiers in
each module. If a module fails, it may be replaced while the unit continues to
operate (at a reduction in output power).
Each of the paralleled amplifiers is protected by a 10 ampere fast-acting fuse.
When a fuse opens, the indicator light next to it comes illuminates and built-in
redundancy allows the unit to continue operation. The fuse can be replaced while
the unit is operating. Fuses 1 and 2 represent amplifiers 1 and 2 on the top left
module. Fuses 3 and 4 represent amplifiers 3 and 4 on the top right module. Fuses
5 and 6 represent amplifiers 5 and 6 on the lower left power module. Fuses 7 and 8
represent amplifiers 7 and 8 on the lower right power module.
Fuses and Indicators
Fault
Power Out
PA Temp
PA Voltage
Tot Current
PA1
PA2
PA5
PA6
PA3
PA4
PA7
PA8
Antenna
RF Drive
PA Temp
PA DC
Fuses
PA1
PA2
PA3
PA4
PA5
PA6
PA7
PA8
fi
Illustration 3–9 Fuse Indicators
3–8
FM2000A User’s Manual
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Section 4—Principles of Operation
This section discusses the circuit principles upon which the
power amplifier and power supply function. This information is
not needed for day-to-day operation, but may be useful for advanced users and service personnel.
Principles of Operation
4–1
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Introduction
The FM2000A is a solid state RF amplifier package designed to deliver 500 to 2000
watts. The package consists of two separate, compact units—a power supply
(PS2000) and a power amplifier (PA2000). In turn, these units consist of modular
components which provide for efficient operation as well as ease-of-service.
4.1 PA2000 Power Amplifier
The PA2000 power amplifier features adjustable output to deliver 500–2000 watts of
RF output power for broadcast transmission. The amplifier is broadband; no tuning
is required. The design, however, ensures efficient operation. Typical RF efficiency
is 75% to 85% across the FM band.
4.1.1 Power Modules
The primary components of the PA2000 are four, 500–watt power modules. These
power modules are mounted by stacking two in the left cavity and two in the right
cavity of the chassis.
The chassis of the power modules acts as a heat sink for the MOSFET amplifiers.
There are two power amplifiers mounted to spacer plates on each of the heat sinks,
for a total of eight power amplifiers in all. (The power amplifiers are the same as
those utilized in the Crown Broadcast 100, 250, 500, and 1000–watt transmitters.)
Power from the amplifiers is combined through a micro-strip combiner to convert
from 50 Ω output impedance for each amplifier to an intermediate impedance and
then return to the 50 Ω output at the Low Pass Filter. This technology eliminates
tuning and adjustments throughout the 88–108 FM band and enables each amplifier
to equally share the power load. The power combiner is also designed to allow a
module to be disconnected from the combiner and removed without adversely
affecting the impedance balance of the unit. With one module removed the impedance change allows the remaining modules to continue operation at approximately
three-fourths of the full output power.
4.1.2 Power Combiner Board
There are four Power Combiner Boards; one attached to each of the four heatsinks
overlapping the amplifiers. Each board takes the power from two amplifiers and
combines it through a parallel quarter-wave transmission line transformer network.
The power is then summed in a common point junction on the Output Combiner
Board.
4–2
FM2000A User’s Manual
4.1.3 Backplane Assembly
The backplane assembly is located in the vertical center of the PA2000 behind the
four power modules. The Backplane Assembly is the common connection point for
the major sections of the transmitter. This assembly consists of the Input Divider
Board, Output Combiner Board, and a Backplane Interconnect Board.
4.1.3.1 Backplane DC Interconnect Board
This board is located nearest the metal inner brace of the chassis. It distributes DC
power to each of the four MOSFET amplifiers, provides the interconnections for
control of the power supply, and enables connection to the remote control interface. The Backplane/DC Interconnect Board contains interconnections from the
Control and Metering Board to the DC Fuse and Power Distribution Board, as well
as power connections to the power amplifier modules.
4.1.3.2 Input Divider Board
The Input Divider Board is the middle board sandwiched between the Backplane DC
Interconnect Board and the Output Combiner Board. It provides the power division
and impedance transformation needed to supply proper drive to each of the eight
amplifiers.
4.1.3.3 Output Combiner Board
The Output Combiner Board is located nearest the Output Filter It consists of a
micro-strip transmission line that combines the output power from the four power
amplifier modules so that ultimately, all the power comes together at one common
point junction. Here the currents and voltages of all four power amplifier modules
are in phase and producing equal RF output power. From this common point
junction, the Output Combiner Board uses a second quarter-wave transformer to
convert the output power to the 50–ohm impedance needed at the output of the
unit.
4.1.4 Output Filter & Reflectometer
The Output Filter/Reflectometer is located behind the Backplane Assembly in the
center of the PA2000. See the accompanying schematic in Section 6 for more
information.
The ninth-order, elliptic, low-pass filter attenuates harmonics generated in the
power amplifier. The capacitors for the filter are circuit board pads. The reflectometer uses printed circuit board traces for micro-strip transmission lines. Transmission line segments (with an impedance of about 100 ohms) on either side of a
50–ohm conductor provide sample voltages representative of the square root of
forward and reverse power. DC voltages, representative of forward and reflected
power, go through a bulkhead Filter Board to the Backplane/DC Interconnect
Board, then to the Metering Board where they are processed for power control and
metering and for SWR metering and protection.
Principles of Operation
4–3
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4.1.5 Metering and Control Board
The Metering and Control Board is located above the upper left cavity. This board
supplies readings of voltages and currents, and provides information on the operation of the amplifier.
The Local Power Adjust pot sets the upper limit (maximum) of RF power output.
The on-board RAISE and LOWER push buttons and any external remote control of
the power level is activated within that limit by placing the Local/Remote slide
switch on the board into the Remote position. When a specific output power is set,
the Metering and Control Board controls and maintains the setting keeping power
constant. A long-life battery supplies power to retain the power setting after the
amplifier is turned off.
This board also takes samples from the RF amplifier boards and PS1000 power
supply and processes all the data. It provides SWR readings from the Output Filter
and folds back the amplifier power if the SWR exceeds safe operating limits. Protection circuitry for overcurrent and overtemperature conditions is designed into this
board as well, providing additional precaution against overheating. This board is
fail-safe, like all the other circuit board components in the FM2000A and can be
removed for repair/replacement if necessary.
4.1.6 DC Fuse and Power Distribution Board
This board is located above the right cavity over Power Modules A and B. The DC
Fuse and Power Distribution Board takes power direct from the power supply
through one 80–amp power line, divides it into eight separate DC power lines, and
distributes it to the eight power amplifiers. Metering resistors in each of the eight
power lines monitor the current drawn by each of the eight amplifiers to ensure
proper function for monitor and control of the unit.
4.1.7 Cooling Fans
There are two cooling fans located in the back of the PA2000 powered by the
PS2000. The fans operate at 24 volts and is rated at 235 cubic feet per minute.
Cool air is drawn through the heatsinks where a flushing moves the air over the DC
Distribution Fuse board, the Control and Metering Board, the Output Filter circuits, and then out through the air vents on the side panels. If a fan fails, the
amplifier will fold back power to prevent overheating.
4–4
FM2000A User’s Manual
4.2 PS2000 Power Supply
The PS2000 supplies power to the PA2000 by converting single-phase 240 VAC
into 50 VDC. The PS2000 is protected by a 20 A double-pole circuit breaker.
This highly efficient power supply utilizes switching technology and is power factor
corrected. The PS2000 consists of three printed circuit boards described below.
4.2.1 AC Input Board
The AC Input Board is located on the left side of the PS2000. AC power from the
circuit breaker connects to the AC Input Board where it connects to a ±12 volt DC
power supply and three relays. The ±12 volts is used to close the three relays when
the DC Power Switch on the front panel is switched on. In addition, the ±12 volts
are supplied to the PA2000 for use in the Control and Metering Board. The 240volt AC input to the power supply is connected through a Hubble Twist Lock
connector on the back panel to a 20–amp circuit breaker mounted inside the back
panel.
When the power supply is turned on and enabled, the AC power comes through
torroidal inductors which prevent harmonics and spurious products from feeding
back into the AC power lines. The current flows from the inductors to a bridge
rectifier that converts the current to DC Power, and from there to the PFC Switching Board where the rectified DC is filtered. The filtered DC power is then fed from
the PFC Switching Board through an 80–turn boost inductor and back to the PFC
Switching Board.
4.2.2 PFC (Power Factor Correcting) Switching Board
The PFC Switching Board is located directly behind the cooling fans (front panel) in
the PS2000. This board takes the voltage from the Torroidal Boost Inductor and
sends it to the Boost Switching Transistor. The switching transistor chops the DC
input power at a 25 kHz rate. The chopped voltage is then rectified, filtered, and
sent as DC voltage to a set of four transistors which form a second switching stage.
The second switching stage chops the DC voltage at a 22.5 kHz rate. This chopped
DC power is fed through a blocking capacitor to a transformer on the DC Output
Board. The second switching stage controls the amount of power sent to the DC
Output Board. This ensures that the transformer output voltage and current are
correct for providing the selected RF output power to the amplifier.
Principles of Operation
4–5
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4.2.3 DC Output Board
The DC Output Board is located in the back of the unit directly behind the PFC
Switching Board. This board rectifies and filters the transformer output voltage
once again to produce the clean DC power required for the power modules. The DC
Output Board also provides the 24 volts that operate the cooling fans in both the
PS2000 and the PA2000. There are two parallel paths from the DC Output Board,
with half the power going through each set of output cables. These cables come
together at the terminal in back of the unit providing the maximum output power
of 50 volts at 60 amperes.
4.2.4 Cooling Fans
There are two cooling fans located in the front section of the PS2000. Their primary function is to cool the semiconductors used in the switching and rectifying
process which are subject to high currents. The fans blow cool air through the
heatsinks and out through the vents on the back and side panels of the PS2000.
The fans have a dedicated circuit breaker located on the back panel of the power
supply.
4–6
FM2000A User’s Manual
TROUBLE
Section 5—Troubleshooting
This section describes procedures for service personnel to diagnose and troubleshoot potential fault conditions in the power
amplifier and power supply.
Troubleshooting
5–1
TROUBLE
5.1 Troubleshooting Flow Chart Analysis
Does your
amplifier have
output power?
Is power
output at the
proper level?
Yes
Yes
No
Do you have
power now?
No
Is exciter delivering
sufficient RF drive?
(Check In Ref meter
reading.)
Are there any
fault
indicators?
Yes
See Section 3.1
Initial Power-up
procedures.
No
Yes
No
Is your exciter
turned on?
See Section 3.1
Initial Power-up
procedures.
Yes
Yes
No
No
Turn the
exciter on.
Antenna: See
Section 5.3.1
Secure all
connections to the
PS2000.
RF Drive: See
Section 5.3.2
Ensure AC input
circuit breaker is
flipped up
PA Temp: See
Section 5.3.3
PA DC: See
Section 5.3.4
Ensure main
power switch is
turned on.
Call Support—
See Section 8
5–2
FM2000A User’s Manual
5.2 Digital Multimeter Parameters
The following procedures are general in nature; for in-depth service, and repair see
the Service & Support section of this manual.
WARNING
Lethal voltages present!
Only technically qualified
individuals shoud attempt
troubleshooting or service
procedures.
If any abnormal readings are displayed for any of the following parameters on the
Digital Multimeter, try troubleshooting in the following manner:
5.2.1 In Ref (Input Drive Reference)
If this indication of drive level is not between 0.8 and 1.2 volts, then:
q Check the exciter to ensure proper power input level of 70–80 watts.
q Check RF input cable for secure connection.
5.2.2 SWR (Standing Wave Ratio)
If the SWR is over 1.5:1, then look for:
q effects of inclement weather such as icing on the antenna and feed line.
q for moisture in the feedline.
q insecure antenna connections.
5.2.3 ALC (Automatic Level Control)
If this indication is not between 4.00 and 6.00 volts for 2.2 kW output, then:
q Check for overheating (see PA Temp fault LED).
q Check for overcurrent (see PA DC fault LED).
q Check for high SWR (see Antenna fault LED).
5.2.4 Power Out
This reading is user adjustable, but for full output should read 2.20 for 2.2 kW.
q If lower than desired, check for proper input drive, and/or proper adjustment
of the Local Power Control (see section 3.1 #6).
Troubleshooting
5–3
TROUBLE
5.2.5 PA Temp
The meter should read between 35–50°C with an ambient temperature of 25°C. If
temperature is 75°C or above, then check and do the following:
❑ Ambient temperature higher than 50°C; reduce temperature.
❑ Restricted air flow; remove any obstructions, clean dirty air filters by using
mild detergent and warm water.
❑ Possible antenna mismatch; check for icing, moisture in the feedline, and
secure antenna connections.
❑ Overcurrent: If PA DC fault indicator is flashing, monitor the current for a
proper level—the total current and the current of individual Power Amps.
5.2.6 PA Voltage
Supply voltage to the RF power amplifiers should be 50 V. If it is not check:
❑ drive level to ensure proper power level input of 70–80 watts
❑ for high SWR
❑ for overcurrent; check PA DC fault indicator and if flashing, check current for
proper levels (total and individual Power Amps)
❑ for overtemperature; ambient temperature higher than 50°C; reduce temperature. Check air flow; remove any obstructions and clean dirty air filters.
5.2.7 Tot Current
If total current reading is over 65 amperes, then check or do the following:
❑ Reduce power output; check all fault indicators and troubleshoot accordingly.
❑ If one or more of the 500–watt power modules has failed; replace.
❑ High SWR; check for icing, moisture in the feedline, and secure antenna
connections.
5.2.8 PA1–8
If there is 2.5 amps or more difference between the individual PA current readings
(7 to 9 amps typical), then check the following:
❑ Failed/faulty power module (reading directly correlates to failed power module); replace.
❑ Blown individual power amplifier fuses 1–8; replace as indicated by red LED.
❑ Reduced power output; check all fault indicators and troubleshoot accordingly.
5–4
FM2000A User’s Manual
5.3 Fault Indicators
If one of the LED fault indicators is illuminated red, troubleshoot using the following suggestions:
5.3.1 Antenna
Antenna mismatch.
❑ Effects from inclement weather conditions such as icing.
❑ Check for moisture in the feedline.
❑ Secure antenna connections.
5.3.2 RF Drive
Denotes lack of or insufficient drive level.
❑ Ensure proper drive level of 70–80 watts input power.
❑ Check RF input cable for secure connection.
5.3.3 PA Temp
Temperature has reached the internal preset limit for safe operation (75°C).
❑ Ambient temperature higher than 50°C; reduce temperature.
❑ Restricted air flow; remove any obstructions, clean dirty air filters by using
mild detergent and warm water.
❑ Antenna mismatch; check for icing, moisture on the feedline, and secure
antenna connections.
❑ Overcurrent; check PA DC fault indicator, if flashing monitor current for
proper levels (total and individual Power Amps).
❑ Faulty DC Output Board; replace (see Section 7, Service & Support).
❑ Faulty or non-functioning cooling fan; determine the cause for malfunction
in the following section.
5.3.3.1 Potential Causes for Non-functioning Cooling Fans
The PA2000 and the PS2000 have two cooling fans each. All fans are powered by
the same circuit of the PS2000. There are two potential causes for a non-functioning fan or fans:
1. If a single fan does not operate, the fan is faulty and must be replaced. (See
Section 7, Service & Support.)
2. If none of the fans operate, a blown circuit breaker, a short circuit in the
PS2000, or a damaged winding on the main transformer of the DC Output
Board (in the PS2000) is the cause. In this case, do one of the following:
Troubleshooting
5–5
TROUBLE
a. The circuit breaker is located on the rear panel of the power supply. If the
breaker has popped out, reset it by pushing it in. If the breaker continues
to trip, check for a short circuit.
b. Check each fan with a volt-ohm meter by disconnecting and testing it for a
short circuit. Replace the fan/fans as needed (see Section 7).
c. If none of the fans have short circuits, there is damage on the winding of
the transformer. It will have to be replaced (see Section 7).
5.3.4 PA DC
Discrepancy in current between the individual amplifiers, or in total current.
❑ There is a difference of current greater than 2.5 amps between any one of the
4 individual amplifiers. This could occur as a result of a blown or faulty power
module, or a blown fuse; replace as appropriate (see Section 7, Service &
Support).
❑ There is too much total current—power foldback will occur above maximum
total amperage of 65 amps due to some malfunction. For antenna mismatch
check for arcing and moisture. Also, check output power for proper current;
the RF detection circuit could malfunction causing an overcurrent situation.
5.3.5 Multiple Indicators
Call your Crown Broadcast service representative. See Section 7, Service and
Support, for contact information.
5–6
FM2000A User’s Manual
Section 6—Reference Drawings
The illustrations in this section may be useful for making
adjustments, taking measurements, troubleshooting, or
understanding the circuitry of your RF power amplifier and
power supply.
Reference Drawings
6–1
6.1 Views
Metering
Fault
In Ref
SWR
ALC
Power Out
PA Temp
PA Voltage
Tot Current
PA1
PA2
PA5
PA6
PA3
PA4
PA7
PA8
Antenna
RF Drive
PA Temp
PA DC
Fuses
PA1
PA2
PA3
PA4
PA5
PA6
PA8
PA7
®
Power
I
O
®
Illustration 6–1 Front View
+ DC Input
RF Monitor
(Optional Connection)
RF Input
Ground Screws
DC Input
Air Intakes/Filters
PA2000
Remote I/O
RF Output
Control
Circuit Breakers
+ DC Output
OFF
Fans
OFF
Power
Control
DC Output
PS2000
Air Exhaust Vents
240 VAC IN
Illustration 6–2 Back View
6–2
FM2000A User’s Manual
6.2 Diagrams and Schematics
50-70 watt exciter
(Crown FM100)
RF Input
RF output
2 kW RF
Power Output
PA2000
Power Amplifier
To remote control and
monitoring equipment
I/O
240 volts AC
50/60 Hz Input Power
Single Phase
Control
DC input
Control
DC output
PS2000
Power Supply
Illustration 6–3 FM2000A Block Diagram
Reference Drawings
6–3
6–4
AC INPUT
240 VAC
AC
CIRCUIT
BREAKER
NEUTRAL
360 VDC
AC
INPUT
CCA
RECTIFIER
220 VDC
GROUND
PFC &
CONTROL
CCA
+ 0 to 50 VDC
360 VDC
CONTROL
+/ 12 VDC
POWER
SWITCH
9-PIN
DSUB
VOLTAGE
BOOST
INDUCTOR
PS CONTROL
FM2000A User’s Manual
Illustration 6–4 PS2000 Block Diagram
DC
OUTPUT
CCA
RETURN
6–8
FM2000A User’s Manual
Illustration 6–5 PA2000 Block Diagram
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Note: All bypass capacitors are 0.01 mf
Backplane Distribution
6–13
FM2000A User's Manual
Ribbon Cables and Connectors
Ribbon Cables and Connectors
Reference Drawings
6–14
Notes:
Reference Drawings
6–16
Section 7—Service and Support
We understand that you may need various levels of support or
that the product could require servicing at some point in time.
This section provides information for both of these scenarios.
Service and Support
7–1
7.1 Service
The product warranty (see opposite page) outlines our responsibility for defective
products. Before returning a product for repair or replacement (our choice), call
our Customer Service department using the following telephone number:
(866) 262-8915
Our Customer Service Representative will give you further instructions regarding
the return of your product. Use the original shipping carton or a new one obtained
from Crown. Place shipping spacers between the slide-out power amplifier assembly and the back panel.
Please fill out the Factory Service Instructions sheet (page 7–5) and include it with
your returned product.
7.2 24–Hour Support
In most instances, what you need to know about your product can be found in this
manual. There are times when you may need more in-depth information or even
emergency-type information. We provide 24–hour technical assistance on your
product via a toll telephone call.
For emergency help or detailed technical assistance, call
(866) 262-8915
You may be required to leave a message at this number but your call will be
returned promptly from our on-call technician.
7.3 Spare Parts
To obtain spare parts, call Crown Broadcast Sales at the following number.
(866) 262-8915
You may also write to the following address:
Service Manger
International Radio and Electronics Company, Inc.
25166 Leer Drive
Elkhart, Indiana, U.S.A. 46514-5425
7–2
FM2000A User's Manual
Crown Broadcast Three Year Limited Product Warranty
SUMMARY OF WARRANTY
Crown Broadcast, IREC warrants its broadcast products to the ORIGINAL PURCHASER of a NEW Crown
Broadcast product, for a period of three (3) years after shipment from Crown Broadcast. All products are
warranted to be free of defects in materials and workmanship and meet or exeed all specifications published
by Crown Broadcast. Product nameplate with serial number must be intact and not altered in any way. This
warranty is non - transferable. This warranty in its entirety is the only warranty offered by Crown Broadcast. No
other warranties, expressed or implied, will be enforceable.
EXCLUSIONS
Crown Broadcast will not warranty the product due to misuse, accident, neglect and improper installation or
operation. Proper installation included A/C line surge supression, lightning protection and proper grounding of
the entire transmitter, and any other recommendations designated in the Instruction manual. This warranty
does not extend to any other products other than those designed and manufactured by Crown Broadcast. This
warranty does not cover any damage to any accessory such as loads, transmission line or antennas resulting
from the use or failure of a Crown Broadcast transmitter. Warranty does not cover any loss of revenue resulting
from any failure of a Crown Broadcast product, act of God, or natural disaster.
Procedure for Obtaining Warranty Service
Crown Broadcast will repair or service, at our discretion, any product failure as a result of normal intended use.
Warranty repair can only be performed at our plant facility in Elkhart, Indiana USA or at a factory authorized
service depot. Expenses in remedying the defect will be borne by Crown Broadcast, including two-way ground
transportation cost within the continental United States.
Prior to returning any product or component to Crown Broadcast for warranty work or repair, a Return
Authorization (RA) number must be obtained from the Crown Broadcast Customer Service Department.
Product must be returned in the original factory pack or equivalent. Original factory pack materials may be
obtained at a nominal charge by contacting Crown Broadcast Customer Service. Resolution of the defective
product will be made within a reasonable time from the date of receipt of the defective product.
Warranty Alterations
No person has the authority to enlarge, amend, or modify this warranty, in whole or in part. This warranty is not
extended by the length of time for which the owner was deprived the use of the product. Repairs and
replacement parts that are provided under the terms of this warranty shall carry only the unexpired portion of
the warranty.
Product Design Changes
Crown Broadcast reserves the right to change the design and manufacture of any product at any time without
notice and without obligation to make corresponding changes in products previously manufactured.
Legal Remedies of Purchaser
This written warranty is given in lieu of any oral or implied warranties not covered herein. Crown Croadcast
disclaims all implied warranties including any warranties of merchantability or fitness for a particular purpose.
Crown Broadcast
25166 Leer Drive
Elkhart, Indiana 46514-5425
Phone 574-262-8900 Fax 574-262-5399 www.crownbroadcast.com
Service and support
7–3
Notes:
7–4
FM2000A User's Manual
Factory Service Instructions
To obtain factory service, complete the bottom half of this page, include it with the unit, and ship to:
International Radio and Electronics Company, Inc.
25166 Leer Drive
Elkhart, Indiana, U.S.A. 46514-5425
For units in warranty (within 3 years of purchase from any authorized Crown Dealer): We pay for
ground UPS shipments from anywhere in the continental U.S. and Federal Express Second Day service
from Hawaii and Alaska to the factory and back to you. Expedited service/shipment is available for an
additional charge. You may ship freight collect (COD for cost of freight) or forward your receipt for
shipping charges which we will reimburse. We do not cover any charges for shipping outside the U.S.
or any of the expenses involved in clearing customs.
If you have any questions about your Crown Broadcast product, please contact Crown Broadcast
Customer Service at:
Telecphon: (574) 262-8900
Fax: (574) 262-5399
Name:
Company:
Shipping Address:
Phone Number:
Model:
Fax:
Serial Number:
Purchase Date:
Nature of the Problem
(Describe the conditions that existed when the problem occurred and what attempts were made to correct it.)
Other equipment in your system:
If warranty has expired, payment will be:
Card Number:
Cash/Check
VISA
Please Quote before servicing
Exp. Date:
Return Shipment Preference if other than UPS Ground:
Mastercard
COD
Signature:
Expedite Shipment
Other
ENCLOSE WITH UNIT—DO NOT MAIL SEPARATELY
Service and Support
7–5
A B C
Glossary
The following pages define terms and abbreviations used
throughout this and other Crown Broadcast manuals.
Glossary
G–1
A B C
AF
Audio Frequency; the frequencies between 20 Hz
and 20 kHz in the electromagnetic spectrum.
ALC
Automatic Level Control
AM
Amplitude Modulation; the process of impressing
information on a radio-frequency signal by varying
its amplitude.
bandwidth
The range of frequencies available for signalling.
BCD
Binary-Coded Decimal; a digital system that uses
binary codes to represent decimal digits.
BFO
Beat Frequency Oscillator
BNC
A bayonet locking connector for miniature coax;
said to be short for Bayonet-Neill-Concelman.
broadband
As used in the FM transmitter, refers to the entire
audio spectrum as opposed to the spectrum influenced by the pre-emphasis; also called "Wideband."
carrier
A continuous signal which is modulated with a
second, information-carrying signal.
crosstalk
In FM broadcasting, this term generally refers to
the interaction between the main (L+R) and the
subcarrier (L–R) signals as opposed to "separation"
which generally refers to leakage between left (L)
and right (R) channels.
density (program)
A high average of modulation over time.
deviation
The amount by which the carrier frequency
changes either side of the center frequency.
DIP
Dual In-line Package; term used to describe an IC
or socket that has two parallel rows of pins.
distortion
The unwanted changes in signal wave shape that
occur during transmission between two points.
DPM
Digital Panel Meter
EPROM
Erasable Programmable Read Only Memory
ESD
Electrostatic Discharge; a discharge that is
potentially distructive to sensitive electronic
components.
G–2
FM2000A User's Manual
exciter
FET
(1) A circuit that supplies the initial oscillator
used in the driver stage. (2) A transmitter configuration which excludes stereo generation and
audio processing.
Field-Effect Transistor
frequency synthesizer
A circuit that generates precise frequency signals
by means of a single crystal oscillator in conjunction with frequency dividers and multipliers.
FM
Frequency Modulation; the process of impressing
information on a radio signal by varying its frequency.
FSK
Frequency Shift Keying; an FM technique for
shifting the frequency of the main carrier at a
Morse code rate. Used in the on-air identification
of frequencies.
gain reduction
The process of reducing the gain of a given amplifier.
harmonics
Undesirable energy at integral multiples of a
desired, fundamental frequency.
HF
High Frequency; Frequencies in the 3.0 to 30.0
MHz range.
Highband
Frequencies affected by the pre-emphasis.
IC
Integrated Circuit
I/O
Input/Output
LED
Light-Emitting Diode
modulation
The process by which a carrier is varied to represent an information-carrying signal.
MOSFET
Metal Oxide Semiconductor Field Effect Transistor;
a voltage-controlled device with high input impedance due to its electrically isolated gate.
nearcast
A transmission within a localized geographic area
(ranging from a single room to a several kilometers).
PA
Power Amplifier
Glossary
G–3
A B C
PAI
Power Amplifier Current
PAV
Power Amplifier Voltage
pilot
A 19–kHz signal used for stereo transmissions.
pre-emphasis
The deliberate accentuation of the higher audio
frequencies; made possible by a high-pass filter.
processing
The procedure and/or circuits used to modify
incoming audio (keeping its level around 75 kHz
deviation) to make it suitable for transmission.
receiver
An option which adds incoming RF capability to an
existing transmitter. See also "Translator."
RF
Radio Frequency; (1) A specific portion of the
electromagnetic spectrum between audio-frequency and the infrared portion. (2) A frequency
useful for radio transmission (roughly 10 kHz and
100,000 MHz).
SCA
Subsidiary Communications Authorization; see
"subcarrier."
S/N
Signal to Noise
spurious products
Unintended signals present on the transmission
output terminal.
stability
A tolerance or measure of how well a component,
circuit, or system maintains constant operating
conditions over a period of time.
stereo pilot
See "pilot."
stereo separation
The amount of left-channel information that
bleeds into the right channel (or vice versa).
subcarrier
A carrier signal which operates at a lower frequency than the main carrier frequency and which
modulates the main carrier.
suppression
The process used to hold back or stop certain
frequencies.
G–4
FM2000A User's Manual
SWR
Standing-Wave Ratio; on a transmission line, the
ratio of the maximum voltage to the minimum
voltage or maximum current to the minimum
current; also the ratio of load impedance to
intended (50 ohms) load impedance.
THD
Total Harmonic Distortion
translator
A transmitter designed to internally change an
FM signal from one frequency to another for
retransmission. Used in conjunction with terrestrial-fed networks.
satellator
A transmitter equipped with an FSK ID option for
rebroadcasting a satellite-fed signal.
UHF
Ultra High Frequency; frequencies in the 300 to
3000 MHz range.
VCO
Voltage-Controlled Oscillator
VHF
Very High Frequency; frequencies in the 30 to
300 MHz range.
VSWR
Voltage Standing-Wave Ratio; see "SWR."
Wideband
See "broadband."
Glossary
G–5
Index
A
AC Input Board 4–5
AC Power 1–3
AC power 2–4
ALC 3–4, 5–3
Antenna 3–7
mismatch 5–5
antenna 2–5
I
B
labels 1–4
Backplane Assembly 4–3
Backplane DC Interconnect Board 4–3
Board Layouts 6–3
M
C
Circuit Breaker 3–4
Combiner Board 4–2
Connections 2–5
Connectors
Hubble Twist Lock® 2–4
Hubble Twist-Lock 2–6
connectors 2–5
D
DC Fuse and Power Distribution Board
4–4
DC Output Board 4–6
DC Power Switch 3–5
Digital Multimeter 3–6, 5–3
E
Efficiency 1–3
efficiency 1–2
exciter 1–2
F
Fans 4–4, 4–6, 5–5
Fault Indicators 3–7, 5–5
Frequency Range 1–3
Fuse Indicators 3–8
H
In Ref 3–4, 5–3
Input Divider Board 4–3
Installation 2–5
Interlock Switch 3–5
L
Metering and Control Board 4–4
multimeter display 3–4
O
operation 3–2
Output Combiner Board 4–3
Output Filter & Reflectometer 4–3
P
PA DC 5–6
PA Temp 3–4, 5–4
PA Voltage 5–4
parts
spares 7–2
PFC (Power Factor Correcting)
Switching Board 4–5
power adjust 3–3, 3–4
Power Consumption 1–3
Power Factor 1–3
Power Module 4–2
Power Out 3–4, 5–3
Power Switch 3–4
power switch 3–3
Power-up 3–2
R
remote I/O 2–7
repair
warranty 7–3
RF Drive Requirement 1–3
RF Harmonics 1–3
Humidity Range 1–3
Index-1
RF Output Impedance 1–3
RF output power 1–2
RF Power Output 1–3
RF power output 1–2
RU spaces 1–2
S
S/N Ratio 1–3
Safety 1–4
Schematics 6–3
service
warranty 7–3
Service Instructions 7–5
Spurious Products 1–3
SWR 1–3, 3–4, 5–3
T
Tot Current 5–4
transmitter package 1–2
Troubleshooting Flow Chart 5–2
U
Unpacking 2–2
W
Warranty 7–3
Weight 1–3
Index-2
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