Crown FM30, FM150, FM300 User Manual

FM30/FM150/FM300 Broadcast Transmitter

User's Manual

©2007 Crown Broadcast, a division of

International Radio and Electronics Corporation

25166 Leer Drive, Elkhart, Indiana, 46514-5425 U.S.A. [phone]

Revision Control

Revision Print Date

Initial Release March 2007

Important Notices

©2007, Crown Broadcast, a division of International Radio and Electronics Corporation.
Portions of this document were originally copyrighted by Michael P. Axman in 1994.

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 International Radio and Electronics, Inc.
Printed in U.S.A.

Crown Broadcast 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 Corporation

P.O. Box 2000

Elkhart, Indiana, 46515-2000 U.S.A.

ii

Contents

Section 1– Getting Acquainted 1-1

1.1 Your Transmitter 1-2

1.2 Applications and Options 1-3

1.2.1 Stand Alone 1-4

1.2.2 Backup 1-4

1.2.3 Booster 1-4

1.2.4 Exciter 1-4

1.2.5 Translator 1-5

1.2.6 Satellator 1-6

1.2.7 Nearcasting 1-6

1.3 Transmitter/Exciter Specifications 1-7

1.4 Receiver Specifications 1-9

1.5 Safety Considerations 1-10

1.5.1 Dangers 1-10

1.5.2 Warnings 1-10

1.5.3 Cautions 1-10

Section 2– Installation 2-1

2.1 Operating Environment 2-2

2.2 Power Connections 2-2

2.2.1 AC Line Voltage Setting 2-2

2.2.2 Fuses 2-5

2.2.3 Battery Power 2-5

2.3 Frequency (Channel) Selection 2-5

2.3.1 Modulation Compensator 2-7

2.4 Receiver Frequency Selection 2-7

2.5 RF Connections 2-10

2.6 Audio Input Connections 2-11

2.7 SCA Input Connections 2-12

2.8 Composite Input Connection 2-12

2.9 Audio Monitor Connections 2-13

2.10 Pre-emphasis Selection 2-13

2.11 Program Input Fault Time-out 2-14

2.12 Remote I/O Connector 2-14

iii

Section 3-Operation 3-1

3.1 Initial Power-up Procedures 3-2

3.2 Power Switches 3-4

3.2.1 DC Breaker 3-4

3.2.2 Power Switch 3-4

3.2.3 Carrier Switch 3-4

3.3 Front Panel Bar-Dot Displays 3-5

3.3.1 Audio Processor Input 3-5

3.3.2 Highband and Wideband Display 3-5

3.3.3 Modulation Display 3-5

3.4 Input Gain Switches 3-6

3.5 Processing Control 3-6

3.6 Stereo-Mono Switch 3-6

3.7 RF Output Control 3-7

3.8 Digital Multimeter 3-7

3.9 Fault Indicators 3-8

Section 4-Principals of Operation 4-1

4.1 Part Numbering 4-2

4.2 Audio Processor Circuit 4-3

4.3 Stereo Generator Circuit 4-4

4.4 RF Exciter Circuit Board 4-6

4.5 Metering Circuit Board 4-8

4.6 Motherboard 4-9

4.7 Display Circuit Board 4-10

4.8 Voltage Regulator Circuit Board 4-11

4.9 Power Regulator Circuit Board 4-12

4.10 RF Driver/Amplifier (FM30) 4-12

4.11 RF Driver (FM150/FM300) 4-13

4.12 RF Amplifier (FM150/FM300 4-13

4.13 Chassis 4-14

4.14 RF Output Filter & Reflectometer 4-14

4.15 Receiver Circuit Board Option 4-15

iv

Section 5-Adjustments and Tests 5-1

5.1 Audio Processor Adjustments 5-2

5.1.1 Pre-Emphasis Selection 5-2

5.1.2 Pre-Emphasis Adjustment 5-2

5.2 Stereo Generator Adjustments 5-2

5.2.1 Separation 5-2

5.2.2 Composite Output 5-2
Using a Modulation Monitor 5-3

5.2.3 19kHz Level 5-4

5.2.4 19kHz Phase 5-4

5.3 Frequency Synthesizer Adjustments 5-4

5.3.1 Frequency (Channel) Selection 5-4

5.3.2 Modulation Compensator 5-4

5.3.3 Frequency Measurement and Adjustment 5-4

5.3.4 FSK Balance Control 5-5

5.4 Metering Board Adjustments 5-5

5.4.1 Power Calibrate 5-5

5.4.2 Power Set 5-5

5.4.3 SWR Calibrate 5-5

5.4.4 PA Current Limit 5-6

5.5 Motherboard Adjustments 5-6

5.6 Display Modulation Calibration 5-6

5.7 Voltage Regulator Adjustment 5-6

5.8 Bias Set (RF Power Amplifier) 5-7

5.9 Performance Verification 5-7

5.9.1 Audio Proof of Performance Measurements 5-7

5.9.2 De-Emphasis Input Network 5-7

5.10 Carrier Frequency 5-8

5.11 Output Power 5-8

5.12 RF Bandwidth and RF Harmonics 5-8

5.13 Pilot Frequency 5-8

5.14 Audio Frequency Response 5-9

5.15 Audio Distortion 5-9

5.16 Modulation Percentage 5-9

5.17 FM and AM Noise 5-9

5.18 Stereo Separation 5-9

5.19 Crosstalk 5-9

5.19.1 Main Channel Into Sub 5-10

5.19.2 Sub Channel Into Main

5.20 38kHz Subcarrier Suppression 5-10

5.21 Additional Checks 5-10

5-10

v

Section 6-Reference Drawings 6-1

6.1 Views 6-2

6.2 Board Layouts and Schematics 6-4

Section 7-Service and Support 7-1

7.1 Service 7-2

7.2 24-Hour Support 7-2

7.3 Spare Parts 7-2

Transmitter Output Efficiency Appendix-1

Glossary G-1

Index Index-1

vi

Section 1—Getting Acquainted

This section provides a general description of the FM30, FM150, and
FM300 transmitters and introduces you to safety conventions used

within this document. Review this material before installing or operating
the transmitter.

1-1 Getting Acquainted

1.1 Your Transmitter

The FM30, FM150, and FM300 are members of a family of FM stereo broadcast
transmitters. Crown transmitters are known for their integration, ease-of-use, and
reliability.

The integration is most apparent in the standard transmitter configuration which
incorporates audio processing, stereo generation, and RF amplification without
compromised signal quality. A single Crown transmitter can replace several pieces of
equipment in a traditional system.

Ease-of-use is apparent in the user-friendly front panel interface and in the installation
procedure. Simply select your operating frequency (using 5 external switches), add an
audio source, attach an antenna, and connect AC or DC power and you're ready to
broadcast. Of course, the FM series of transmitters also feature more sophisticated
inputs and monitoring connections if needed.

Reliability is a Crown tradition. The first Crown transmitters were designed for rigors of
worldwide and potentially portable use. The modular design, quality components,
engineering approach, and high production standards ensure stable performance.

Remote control and metering of the transmitter are made possible through a built-in I/O
port. For more direct monitoring, the front panel includes a digital multimeter display and
status indicators. Automatic control circuitry provides protection for high VSWR as well
as high current, voltage, and temperature conditions.

Illustration 1-1 FM150 Stereo Broadcast Transmitter

This manual describes the FM30, FM150, and FM300 because all three transmitters
share common design factors. Specific product differences are noted throughout the
manual. In physical appearance, the FM30 differs from the FM150 and FM300 in that it
lacks the power amplifier and cooling fan assembly on the back panel.

1-2 FM30/FM150/FM300 User’s Manual

1.2 Applications and Options

Crown transmitters are designed for versatility in applications. They have been used as
stand-alone and backup transmitters and in booster, translator, satellator, and nearcast
applications. The following discussion describes these applications further.

Model numbers describe the configuration of the product (which has to do with its intended
purpose) and the RF output power which you can expect.

The number portion of each name represents the maximum RF output power. The FM300,
for example, can generate up to 300 watts of RF output power.

Suffix letters describe the configuration. The FM300T, for example, is the standard or
transmitter configuration. Except where specified, this document describes the transmitter
configuration. In this configuration, the product includes the following components
(functions):

• Audio Processor/Stereo Generator

• RF Exciter

• Metering

• Low-Pass filter

Illustration 1–2 Standard (Transmitter) Configuration

1-3 Getting Acquainted

1.2.1 Stand-Alone

In the standard configuration, the FM30, FM150, and FM300 are ideal stand-alone
transmitters. When you add an audio source (monaural, L/R stereo, or composite signal),
an antenna, and AC or DC power, the transmitter becomes a complete FM stereo broadcast
station, capable of serving a community.
As stand-alone transmitters, Crown units often replace multiple pieces of equipment in a
traditional setup (exciter, audio processor, RF amplifier).

1.2.2 Backup

In the standard configuration, Crown transmitters are also used in backup applications.
Should your primary transmitter become disabled, you can continue to broadcast while
repairs take place. In addition, the FM transmitters can replace disabled portions of your
existing system including the exciter, audio processor, or amplifier. Transfer switches on
each side of the existing and backup transmitters make the change-over possible with
minimal downtime.
The DC operation option of the FM30, FM150, and FM300 make them attractive backup
units for those times when AC power is lost.

1.2.3 Exciter

In addition to the standard configuration, the FM30, FM150, and FM300 are available in op­tional configurations to meet a variety of needs.
An "E" suffix, as in the FM30E, for example, represents an exciter-only configuration. In this
configuration, the audio processor and stereo generator boards are replaced with circuitry to
bypass their function. The exciter configurations are the least expensive way to get Crown
quality components into your transmission system.
You might consider the Crown exciter when other portions of your system are performing
satisfactorily and you want to maximize your investment in present equipment.

1-4 FM30/FM150/FM300 User’s Manual

1.2.4 Translator

A receiver configuration (FM150R, for example) replaces the audio processor/stereo gen­erator board with a receiver module. This added feature makes the FM30, FM150, and
FM300 ideal for translator service in terrestrial-fed networks. These networks represent a
popular and effective way to increase your broadcasting coverage. Translators, acting as
repeater emitters, are necessary links in this chain of events.
Traditionally, network engineers have relied on multiple steps and multiple pieces of equip­ment to accomplish the task. Others have integrated the translator function (receiver and
exciter) to feed an amplifier. Crown, on the other hand, starts with an integrated transmitter
and adds a solid-state Receiver Module to form the ideal translator.

Illustration 1–3 Crown's Integrated Translator

This option enables RF in and RF out on any of Crown’s FM series of transmitters. In addi­tion, the module supplies a composite output to the RF exciter portion of the transmitter.
From here, the signal is brought to full power by the built-in power amplifier for retransmis­sion. The Receiver Module has been specifically designed to handle SCA channel output up
to 100 kHz for audio and high-speed data.
FSK ID programming is built-in to ensure compliance with FCC regulations regarding the
on-air identification of translators. Simply specify the call sign of the repeater station when
ordering. Should you need to change the location of the translator, replacement FSK chips
are available. The Receiver Module option should be ordered at the time of initial transmitter
purchase. However, an option kit is available for field converting existing Crown units.
In the translator configuration there are differences in the function of the front panel, see
Section 3 for a description.

1-5 Getting Acquainted

1.2.5 Satellator

One additional option is available for all configurations—an FSK Identifier (FSK IDer). This
added feature enables the FM30, FM150, and FM300 to transmit its call sign or operating
frequency in a Morse code style. This option is intended for use in satellite-fed networks.
Transmitters equipped in this fashion are often known as "satellators."
Connect the transmitter to your satellite receiver and the pre-programmed FSK IDer does
the rest—shifting the frequency to comply with FCC requirements and in a manner that is
unnoticeable to the listener. The FSK IDer module should be ordered at the time you order
your transmitter, but is available separately (factory programmed for your installation).

Illustration 1–4 Transmitter with FSK IDer Option

Add the FSK IDer option to the exciter configuration for the most economical satellator (a
composite input signal is required).

1.2.6 Nearcasting

The output power of an FM30 transmitter can be reduced to a level that could function as a
near-cast transmitter. Crown transmitters have been used in this way for language transla­tion, for re-broadcasting the audio of sporting events within a stadium, and for specialized
local radio. The FM30 is the only transmitter that is appropriate for this application.

1-6 FM30/FM150/FM300 User’s Manual

1.3 Transmitter/Exciter Specifications

Frequency Range 87.9 MHz–107.9 MHz (76 MHz–90 MHz
optionally available)

RF Power Output (VSWR 1.7:1 or better)

FM30 3-33 Watts adjustable

FM150 15-165 Watts adjustable

FM300 30-330 Watts adjustable

RF Output Impedance 50 Ohms

Frequency Stability Meets FCC specifications from 0-50

degrees C

Audio Input Impedance 50k Ω bridging, balanced, or 600 Ω

Audio Input Level Selectable for –10 dBm to +10 dBm for

75 kHz deviation at 400 Hz

Pre-emphasis Selectable for 25, 50, or 75 µsec; or flat

Audio Response Conforms to 75 µsec pre-emphasis

curve as follows:

Complete Transmitter ±0.30 dB (50 Hz–10 kHz)
±1.0 dB (10 kHz–15 kHz)

Exciter only ±0.25 dB (50 Hz–15 kHz)

Distortion (THD + Noise)

Complete Transmitter Less than 0.7% (at 15kHz)

Exciter only Less than 0.3% (50Hz-15kHz)

Stereo Separation

Complete Transmitter Better than –40dB (50Hz-15kHz)

Exciter only Better than –40dB (50Hz-15kHz)

Crosstalk Main into Sub, better than –40dB
Sub into Main, better than –40dB

Stereo Pilot 19 kHz ±2 Hz, 9% modulation

1-7 Getting Acquainted

Subcarrier Suppression 50dB below ±75 kHz deviation

FM S/N Ratio (FM noise)

Complete Transmitter Better than –60dB

Exciter only Better than –70dB

AM S/N Ratio Asynchronous and synchronous noise
better than FCC requirements

RF Bandwidth ±120 kHz, better than –35 dB

±240 kHz, better than –45 dB

RF Spurious Products Better than –70dB

Operating Environment Temperature (0

°C to 50°C)

Humidity (0 to 80% at 20°C)

9834 Feet

Maximum Altitude (3,000 Meters;

AC Power 100,120, 220, or 240 volts +10%/-

15%); 50/60Hz

FM30 115VA

FM150 297VA

FM300 550VA

DC Power

FM30 24-36 volts (36 volts at 3 amps required
for full output power)

FM150 36-72 volts (48 volts @ 7 amps for full
output power)

FM300 36-72 volts (72 volts @ 10 amps for full
output power)

1-8 FM30/FM150/FM300 User’s Manual

Note: We set voltage and ampere requirements to assist you in designing your system. De­pending on your operating frequency, actual requirements for maximum voltage and current
readings are 10–15% lower than stated.

Regulatory Type notified FCC parts 73 and 74
Meets FCC, DOC, and CCIR requirements

Dimensions 13.5 x 41.9 x 44.5 cm

5.25 x 16.5 x 17.5 inches

Weight
FM30 10.5 kg (23 lbs)

13.6 kg (30 lbs) shipping weight

FM150 11.4 kg (25 lbs)

14.5 kg (32 lbs) shipping weight

FM300 16.8 kg (37 lbs)

20.0 kg (44 lbs) shipping weight

1-9 Getting Acquainted

1.4 Receiver Specifications

Monaural Sensitivity (demodulated, de-emphasized)

3.5 µ V for signal-to-noise > 50 dB

Stereo Sensitivity (19–kHz pilot frequency added)
31 µ V for signal-to-noise > 50 dB

Connector
Standard type N, 50 Ω

Shipping Weight

1 lb

1.5 Safety Considerations

Crown Broadcast assumes the responsibility for providing you with 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.

1.5.1 Dangers

DANGER represents the most severe hazard alert. Extreme bodily harm or death will occur
if DANGER guidelines are not followed.

1.5.2 Warnings

WARNING represents hazards which could result in severe injury or death.

1.5.3 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.

Illustration 1–5 Sample Hazard Alert

1-10 FM30/FM150/FM300 User’s Manual

Section 2—Installation

This section provides important guidelines for installing your transmitter.

Review this information carefully for proper installation.

2-1 Installation

2.1 Operating Environment

You can install the FM transmitter in a standard component rack or on a suitable surface
such as a bench or desk. In any case, the area should be as clean and well ventilated as
possible. Always allow for at least 2 cm of clearance under the unit for ventilation. If you set
the transmitter on a flat surface, install spacers on the bottom cover plate. If you install the
transmitter in a rack, provide adequate clearance above and below. Do not locate the trans­mitter directly above a hot piece of equipment.

2.2 Power Connections

The FM30, FM150, and FM300 operate on 100, 120, 220, or 240 volts AC (50 or 60 Hz; sin­gle phase). Each transmitter can operate on DC power as well (28 volts for the FM30, 48
volts for the FM150, and 72 volts for the FM300). The transmitter can operate on fewer volts
DC, but with reduced RF output power (see section 1.3). In addition, the transmitter isolates
the AC and DC sources; both can be connected at the same time to provide battery backup
in the event of an AC power failure.

2.2.1 AC Line Voltage Setting

To change the voltage setting, follow these steps:

1. Disconnect the power cord if it is attached.

2. Open the cover of the power connector assembly using a small, flat blade screw
driver. See Illustration 2–1.

3. Insert the screwdriver into the voltage selection slot and remove the drum from the as­sembly.

4. Rotate the drum to select the desired voltage. See Illustration 2–2.

5. Replace the drum and cover and check to see that the correct voltage appears in the
connector window.

6. Connect the AC power cord.

2-2 FM30/FM150/FM300 User’s Manual

Illustration 2–1 Removing the Power Connector Cover

Illustration 2–2 Selecting an AC Line Voltage

2-3 Installation

2.2.2 Fuses

The fuse holders are located in the power connector assembly just below the voltage selec­tor.

Illustration 2–3 Fuse Holder

For 100 to 120 VAC operation, use the fuse installed at the factory. For 220 to 240 VAC op­eration, use the slow-blow fuse located in a hardware kit within the transmitter packaging.
Consult the following table:

Transmitter Input Power Fuse

FM30 100–120 V 3 A

220–240 V 1.5 A

FM150 100–120 V 6.3 A

220–240 V 4 A

FM300 100–120 V 12.5 A

220–240 V 6.3 A

Illustration 2–4 Fuse Reference Table

2-4 FM30/FM150/FM300 User’s Manual

2.2.3 Battery Power

Your transmitter can operate on a DC power source (such as 4 or 5, 12–volt deep cycle bat­teries connected in series). The FM30 requires 28 volts DC for full output power, while the
FM150 requires 48 volts, and FM300 requires 72 volts for full output power. Connect the
batteries to the red (+) and black (–) battery input binding posts on the rear panel.

2–5 Illustration DC Input Terminals

2.3 Frequency (Channel) Selection

Your transmitter is capable of operating between 87.9 and 107.9 MHz in the FM band. The
transmitter can also operate between 76 and 90 MHz by shorting pins 9 and 10 of J20 on

the motherboard. (See illustration 2-6)

To adjust the operating frequency, follow these steps:

1. Locate the frequency selector switches on the front panel which will be used to change
the setting. See Illustrations 2–6 and 2–7.

2-5 Installation

2. Use small flat blade screwdriver or another suitable device to rotate the switches to the
desired setting. (The selected number will appear directly above the white indicator dot
on each switch.) See examples of selected frequencies in the illustration below.

3. To change the operating band from 87.9-107.9MHz to 76-90MHz or vice versa, or to ad­just the modulation compensation pot, remove the top cover to gain access to these fea­tures. See illustrations 2-6 and 2-10.

Illustration 2–6 Top Cover Removed

Megahertz .1

.01

Illustration 2–7 Transmitter Front Panel (Frequency Selector Switches)

= 88.10 MHz

= 107.90 MHz

Illustration 2–8 Two Sample Frequency Selections

2-6 FM30/FM150/FM300 User’s Manual

2.3.1 Modulation Compensator

The Modulation trim-potentiometer (see illustration 2–10) compensates for slight variations
in deviation sensitivity with frequency. Set the trim-pot dial according to the following graph:

Frequency of Operation (MHz)

108 0
106 10
104 15
102 25
100 35

98 40

97.1 45
96 55
94 60
92 70
90 75
88 80
86 80
84 80

82.4 70
82 65
80 55
78 30
76 0

Modulation Compensation Pot Setting

Illustration 2–9 Modulation Compensator Settings

These compensator settings are approximate. Each mark on the potentiometer represents
about 1.8% modulation compensation.

Illustration 2–10 Modulation Compensator Pot

2-7 Installation

2.4 Receiver Frequency Selection

If you have a transmitter equipped with the receiver option, you will need to set the receiving
or incoming frequency.

1. With the top cover removed, locate the receiver module and the two switches (labeled
SW1 and SW2).

Illustration 2–11 Receiver Module Switches

2. Use the adjacent chart to set the switches for the desired incoming frequency.

3. For frequencies in the Japan FM band, short pins 7&8 on J1 on the receiver card.

4. For 75us pre-emphasis short pins 3&4 and 5&6 on J2 of the Receiver card.

5. For 50us pre-emphasis short pins 1&2 and 7&8 on J2 of the Receiver card.

6. After setting the frequency, replace the top cover and screws.

2-8 FM30/FM150/FM300 User’s Manual

Freq. 74-90

MHz

Freq. 88-108

MHz

SW1 SW2 Freq. 74-90

MHz

Freq. 88-108

MHz

SW1 SW2

74.9 87.9 0 0 78.9 91.9 1 4

75.0 88.0 8 0 79.0 92.0 9 4

75.1 88.1 0 1 79.1 92.1 1 5

75.2 88.2 8 1 79.2 92.2 9 5

75.3 88.3 0 2 79.3 92.3 1 6

75.4 88.4 8 2 79.4 92.4 9 6

75.5 88.5 0 3 79.5 92.5 1 7

75.6 88.6 8 3 79.6 92.6 9 7

75.7 88.7 0 4 79.7 92.7 1 8

75.8 88.8 8 4 79.8 92.8 9 8

75.9 88.9 0 5 79.9 92.9 1 9

76.0 89.0 8 5 80.0 93.0 9 9

76.1 89.1 0 6 80.1 93.1 1 A

76.2 89.2 8 6 80.2 93.2 9 A

76.3 89.3 0 7 80.3 93.3 1 B

76.4 89.4 8 7 80.4 93.4 9 B

76.5 89.5 0 8 80.5 93.5 1 C

76.6 89.6 8 8 80.6 93.6 9 C

76.7 89.7 0 9 80.7 93.7 1 D

76.8 89.8 8 9 80.8 93.8 9 D

76.9 89.9 0 A 80.9 93.9 1 E

77.0 90.0 8 A 81.0 94.0 9 E

77.1 90.1 0 B 81.1 94.1 1 F

77.2 90.2 8 B 81.2 94.2 9 F

77.3 90.3 0 C 81.3 94.3 2 0

77.4 90.4 8 C 81.4 94.4 A 0

77.5 90.5 0 D 81.5 94.5 2 1

77.6 90.6 8 D 81.6 94.6 A 1

77.7 90.7 0 E 81.7 94.7 2 2

77.8 90.8 8 E 81.8 94.8 A 2

77.9 90.9 0 F 81.9 94.9 2 3

78.0 91.0 8 F 82.0 95.0 A 3

78.1 91.1 1 0 82.1 95.1 2 4

78.2 91.2 9 0 82.2 95.2 A 4

78.3 91.3 1 1 82.3 95.3 2 5

78.4 91.4 9 1 82.4 95.4 A 5

78.5 91.5 1 2 82.5 95.5 2 6

78.6 91.6 9 2 82.6 95.6 A 6

78.7 91.7 1 3 82.7 95.7 2 7

78.8 91.8 9 3 82.8 95.8 A 7

Illustration 2–12-1 Receiver Frequency Selection

(Continued on next page)

2-9 Installation

Freq. 74-90

MHz

Freq. 88-108

MHz

SW1 SW2 Freq. 74-90

MHz

Freq. 88-108

MHz

SW1 SW2

82.9 95.9 2 8 86.6 99.6 B A

83.0 96.0 A 8 86.7 99.7 3 B

83.1 96.1 2 9 86.8 99.8 B B

83.2 96.2 A 9 86.9 99.9 3 C

83.3 96.3 2 A 87.0 100.0 B C

83.4 96.4 A A 87.1 100.1 3 D

83.5 96.5 2 B 87.2 100.2 B D

83.6 96.6 A B 87.3 100.3 3 E

83.7 96.7 2 C 87.4 100.4 B E

83.8 96.8 A C 87.5 100.5 3 F

83.9 96.9 2 D 87.6 100.6 B F

84.0 97.0 A D 87.7 100.7 4 0

84.1 97.1 2 E 87.8 100.8 C 0

84.2 97.2 A E 87.9 100.9 4 1

84.3 97.3 2 F 88.0 101.0 C 1

84.4 97.4 A F 88.1 101.1 4 2

84.5 97.5 3 0 88.2 101.2 C 2

84.6 97.6 B 0 88.3 101.3 4 3

84.7 97.7 3 1 88.4 101.4 C 3

84.8 97.8 B 1 88.5 101.5 4 4

84.9 97.9 3 2 88.6 101.6 C 4

85.0 98.0 B 2 88.7 101.7 4 5

85.1 98.1 3 3 88.8 101.8 C 5

85.2 98.2 B 3 88.9 101.9 4 6

85.3 98.3 3 4 89.0 102.0 C 6

85.4 98.4 B 4 89.1 102.1 4 7

85.5 98.5 3 5 89.2 102.2 C 7

85.6 98.6 B 5 89.3 102.3 4 8

85.7 98.7 3 6 89.4 102.4 C 8

85.8 98.8 B 6 89.5 102.5 4 9

85.9 98.9 3 7 89.6 102.6 C 9

86.0 99.0 B 7 89.7 102.7 4 A

86.1 99.1 3 8 89.8 102.8 C A

86.2 99.2 B 8 89.9 102.9 4 B

86.3 99.3 3 9 90.0 103.0 C B

86.4 99.4 B 9 X 103.1 4 C

86.5 99.5 3 A X 103.2 C C

Illustration 2–12-2 Receiver Frequency Selection

2-10 FM30/FM150/FM300 User’s Manual

(Continued on next page)

Freq. 74-90

MHz

Freq. 88-108

MHz

SW1 SW2 Freq. 74-90

MHz

Freq. 88-108

MHz

SW1 SW2

X 103.3 4 D X 107.0 D F
X 103.4 C D X 107.1 6 0
X 103.5 4 E X 107.2 E 0
X 103.6 C E X 107.3 6 1
X 103.7 4 F X 107.4 E 1
X 103.8 C F X 107.5 6 2
X 103.9 5 0 X 107.6 E 2
X 104.0 D 0 X 107.7 6 3
X 104.1 5 1 X 107.8 E 3
X 104.2 D 1 X 107.9 6 4
X 104.3 5 2 X 108.0 E 4
X 104.4 D 2
X 104.5 5 3
X 104.6 D 3
X 104.7 5 4
X 104.8 D 4
X 104.9 5 5
X 105.0 D 5
X 105.1 5 6
X 105.2 D 6
X 105.3 5 7
X 105.4 D 7
X 105.5 5 8
X 105.6 D 8
X 105.7 5 9
X 105.8 D 9
X 105.9 5 A
X 106.0 D A
X 106.1 5 B
X 106.2 D B
X 106.3 5 C
X 106.4 D C
X 106.5 5 D
X 106.6 D D
X 106.7 5 E
X 106.8 D E
X 106.9 5 F

Illustration 2–12-3 Receiver Frequency Selection

2-11 Installation

2.5 RF Connections

Connect the RF load, an antenna or the input of an external power amplifier, to the type-N,
RF output connector on the rear panel. VSWR should be 1.5:1 or better.

The RF monitor is intended primarily for a modulation monitor connection. Information
gained through this connection can supplement that which is available on the transmitter
front panel displays.
If your transmitter is equipped with the receiver option, connect the incoming RF to the RF
IN connector.

2-12 FM30/FM150/FM300 User’s Manual

Illustration 2–13 RF Connections

2.6 Audio Input Connections

Attach audio inputs to the Left and Right XLR connectors on the rear panel. (The Left
channel audio is used on Mono.) Pin 1 of the XLR connector goes to chassis ground. Pins 2
and 3 represent a balanced differential input with an impedance of about 50 kΩ . They may
be connected to balanced or unbalanced left and right program sources.
The audio input cables should be shielded pairs, whether the source is balanced or unbal­anced. For an unbalanced program source, one line (preferably the one connecting to pin 3)
should be grounded to the shield at the source. Audio will then connect to the line going to
pin 2.

Illustration 2–14 XLR Audio Input Connectors

By bringing the audio return line back to the program source, the balanced differential input
of the transmitter is used to best advantage to minimize noise. This practice is especially
helpful if the program lines are fairly long, but is a good practice for any distance.
If the program source requires a 600 Ω termination, see the motherboard configuration chart
on page 4-9 for the proper configuration of the jumpers.

2-13 Installation

2.7 SCA Input Connections

You can connect external SCA generators to the SCA In connectors (BNC-type) on the rear
panel. The inputs are intended for the 60 kHz to 99 kHz range, but a lower frequency may
be used if the transmitter is operated in Mono mode. (The 23 to 53 kHz band is used for ste­reo transmission.) For 7.5 kHz deviation (10% modulation), input of approximately 3.5–volts
(peak-to-peak) is required.

Illustration 2–15 SCA Input Connectors

2.8 Composite Input Connection

You may feed composite stereo (or mono audio) directly to the RF exciter bypassing the in­ternal audio processor and stereo generator. To use the Crown transmitter as an RF Exciter
only ("E" version or when using the "T" version with composite input), it is necessary to use
the Composite Input section of the transmitter. This will feed composite stereo (or mono au­dio) directly to the RF exciter. In the "T" version, this will bypass the internal audio proces­sor and stereo generator.

Input sensitivity is approximately 3.5–volt P-P for 75 kHz deviation.

1. Enable the Composite Input by grounding pin 14 of the Remote I/O connector

(see Illustration 2–18).

2. Connect the composite signal using the Composite In BNC connector.

2-14 FM30/FM150/FM300 User’s Manual