Crown CM-150 User Manual

FM30/FM150/FM300 Broadcast Transmitter User's Manual ©2007 Crown Broadcast, a division of International Radio and Electronics Corporation 25166

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 (monaur

Appendix Transmitter Output Efficiency RF Power Output-FM 30 PADC Volts PADC Amps RF Power

Transmitter Output Efficiency RF Power Output-FM 150 PADC Volts PADC Amps RF Power E

Notes: FM30/FM150/FM300 User’s Manual A-3

Glossary The following pages define terms and abbreviations used throughout this manual. Glossary G-1

AF Audio Frequency; the frequencies between 20 Hz

FET Field-Effect Transistor Frequency Synthesizer

RF Radio Frequency;

Index Symbols 19–kHz level adjustment 5–3 phase adjustment 5–3 A AC. See Power: input ALC 3–3,3–7,4–7 Altitude operating ran

D DC. See Power: input De-emphasis 2-15, 5-2, 5-7 jumpers 2-15 Delay program failure to carrier turnoff 2-16, 5-6 Dimensio

M (continued) Mono operation 2-13, 3-6 Motherboard circuit description 4-8 Multimeter 3-7 front panel

1.2.4 Translator A receiver configuration (FM150R, for example) replaces the audio processor/stereo gen-erator board with a receiver module. This ad

S (continued) Stand alone transmitter use 1-4 Stereo separation 1-7, 5-9 Stereo generator 1-2, 2-14 adjustme

1.2.5 Satellator One additional option is available for all configurations—an FSK Identifier (FSK IDer). This added feature enables the FM30, FM150,

1.3 Transmitter/Exciter Specifications Frequency Range 87.9 MHz–107.9 MHz (76 MHz–90 MHz

Subcarrier Suppression 50dB below ±75 kHz deviation FM S/N Ratio (FM noise)

Note: We set voltage and ampere requirements to assist you in designing your system. De-pending on your operating frequency, actual requirements for m

1.4 Receiver Specifications Monaural Sensitivity (demodulated, de-emphasized) 3.5 µ V for signal-to-noise > 50 dB Stereo Sensitivity (19

Section 2—Installation This section provides important guidelines for installing your transmitter. Review this information carefully for proper inst

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 c

Illustration 2–1 Removing the Power Connector Cover Illustration 2–2 Selecting an AC Line Voltage 2-3 Installation

Revision Control Revision Print Date Initial Release March 2007

2.2.2 Fuses The fuse holders are located in the power connector assembly just below the voltage selec-tor. Illustration 2–3 Fuse Holder For 100 to

2.2.3 Battery Power Your transmitter can operate on a DC power source (such as 4 or 5, 12–volt deep cycle bat-teries connected in series). The FM30

2. Use small flat blade screwdriver or another suitable device to rotate the switches to the desired setting. (The selected number will appear directl

2.3.1 Modulation Compensator The Modulation trim-potentiometer (see illustration 2–10) compensates for slight variations in deviation sensitivity wi

2.4 Receiver Frequency Selection If you have a transmitter equipped with the receiver option, you will need to set the receiving or incoming frequen

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

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

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

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

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.) Pi

Contents Section 1– Getting Acquainted 1-1 1.1 Your Transmitter

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

Illustration 2–16 Composite In and Audio Monitor Connections 2.9 Audio Monitor Connections Processed, de-emphasized samples of the left and right au

2.11 Program Input Fault Time-out You can enable an automatic turn-off of the carrier in the event of program failure. To en-able this option, see i

Pin Number Function 1. Ground 2. FMV Control 3. Composite Out (sample of stere

Notes: 2-18 FM30/FM150/FM300 User’s Manual

Section 3—Operation This section provides general operating parameters of your transmitter and a detailed description of its front panel display.

3.1 Initial Power-up Procedures These steps summarize the operating procedures you should use for the initial operation of the transmitter. More det

3. Verify the following: A. The bottom cooling fan runs continuously. B. The Lock Fault indicator flashes for approximately 5 sec

3.2 Power Switches 3.2.1 DC Breaker The DC breaker, on the rear panel, must be on (up) for transmitter operation, even when using AC power. Electr

3.3 Front Panel Bar-Dot Displays Bar-dot LEDs show audio input levels, wideband and highband audio gain control, and modulation percentage. Resoluti

Section 3-Operation 3-1 3.1 Initial Power-up Procedures

3.4 Input Gain Switches The “+6 dB” and “+12 dB” slide switches set audio input sensitivity according to the following table. Illustrat

3.7 RF Output Control Set this control for the desired output power level. Preferably, set the power with an external RF wattmeter connected in the

PA DC Volts—Supply voltage of the RF power amplifier. PA DC Amps—Transistor drain current for the RF power amplifier. PA DC Temperature—Temperatur

Section 4—Principles of Operation This section discusses the circuit principles upon which the transmitter functions. This information is not needed

4.1 Part Numbering As this section refers to individual components, you should be familiar with the part number-ing scheme used. The circuit boards

4.2 Audio Processor/Stereo Generator Circuit Board The audio board provides the control functions of audio processing-compression, limiting, and exp

Q1 (Q2) is a recover/expansion gate with a threshold about 18 dB below the normal pro-gram level. The amount of short-term expansion and time for gain

Processed, pre-emphasized left and right audio is passed through third-order lowpass filters comprised of U202A (203A) and associated circuitry. The f

4.3 RF Exciter Circuit This circuit is also known as the Frequency Synthesizer. The Frequency Synthesizer part of the motherboard is no longer a se

4.5 Metering Circuit The ALC and metering circuitry is on the motherboard (see Illustration 6–6). This circuit processes information for the RF and

Section 5-Adjustments and Tests 5-1 5.1 Audio Processor Adjustments

4.6 Motherboard The motherboard is the large board in the upper chassis interconnecting the audio proces-sor/stereo generator board or the optional

Jumper FMA “E” FMA“T” 50KΩ input FMA“T” 600Ω input FMA “R” FMA “Omnia” Anal og input FMA “Omnia” AES input Z1 Short Short Short Short Short Op

4.7 Display Circuit Board The front-panel LEDs, the numeric display, the slide switches, and the processing and RF level controls are mounted on the

4.8 Voltage Regulator Circuit Board The voltage regulator board is the longer of two boards mounted under the chassis toward the front of the unit.

4.9 Power Regulator Circuit Board The power regulator board is the shorter of two boards mounted under the chassis toward the front of the unit. The

4.11 RF Driver (FM150/FM300) The RF Driver assembly is mounted on a 100 mm x 100 mm plate in the under side of the chassis. Illustration 6-14 and

4.13 Chassis The AC power supply components, as well as the bridge rectifier and main filter capacitor, are mounted on the chassis. Switching in the

4.15 Receiver Circuit Board Option This option allows the transmitter to be used as a translator. The receiver board receives terrestrially fed RF s

When a stereo signal is present, LED 3 illuminates which indicates that left and right audio is available. Then the stereo signals go to gain stages a

Section 5—Adjustments and Tests This section describes procedures for (1) advanced users who may be interested in customizing or optimizing the perfo

Section 6-Reference Drawings 6-1 6.1 Views

5.1 Audio Processor Adjustments 5.1.1 Pre-Emphasis Selection Select the pre-emphasis curve (75 µsec, 50 µsec, 25 µsec, or Flat) by jumpering the a

5.2.2 Composite Output You can make adjustments to the composite output in the following manner: Using a Modulation Monitor 1. Set the Stereo-M

5.3.2 Modulation Compensator Refer to section 2.3.1 5.3.3 Frequency Measurement and Adjustment Next to the 10.24–MHz VCXO in the RF Exciter circu

5.4.3 SWR Calibrate When the Carrier switch is off, or the RF power is less than about 5 watts, the SWR circuit automatically switches to a calibrat

5.7 Voltage Regulator Adjustments JP1, a 10–pin header on the Voltage Regulator board, sets the time between program fail-ure and carrier turnoff. P

5.9 Performance Verification Measure the following parameters to receive a comprehensive characterization of trans-mitter performance: • Carrier

5.10 Carrier Frequency Carrier frequency is measured at the output frequency with a frequency monitor or suitable frequency counter. To adjust fre

5.15 Audio Distortion Make distortion measurements from the de-emphasized output of an FM modulation moni-tor. Make audio distortion measurements

5.20 38–kHz Subcarrier Suppression With no modulation, but in the Stereo mode, the 38–kHz subcarrier, as indicated on an FM modulation monitor, shou

Section 6—Reference Drawings The illustrations in this section may be useful for making adjustments, taking measurements, troubleshooting, or underst

Section 1—Getting Acquainted This section provides a general description of the FM30, FM150, and FM300 transmitters and introduces you to safety con

6.1 Views Illustration 6-1 Front View Illustration 6-2 Rear View DC Input Circuit Breaker RF Power Amplifier (FM150/300 Only) AC Power Input RF Output

Illustration 6-3 Chassis Top View Voltage Regulator Power Regulator RF Pre-driver/ Amplifier Bridge Rectifier Filter Capacitor AC Power Transformer AC

6-4 Notes: FM30/FM150/FM300 User’s Manual

Illustration 6-5 Audio Processor/Stereo Generator Board 6.2 Board Layout and Schematics 6-5 FM30/FM150/FM300 User’s Manual

FM30/150/300 User’s Manual Board Layouts and Schematics Schematic Diagram: Audio Processor/ Stereo Generator (Sheet 1 of 2) 1 2 3 4 5 6 7 8 9 10 11

Schematic Diagram: Audio Processor/ Stereo Generator (Sheet 2 of 2) 1 2 3 4 5 6 7 8 9 10 11 12ABCDEFGH121110987654321HGFEDCBADWG. NO. REV.65THESE DRAW

FM30/150/300 User’s Manual Board Layouts and Schematics Illustration 6-6 Motherboard Adjustments and Tests 6-8

Schematic Diagram: Motherboard (Sheet 1 of 3) 1 2 3 4 5 6 7 8 9 10 11 12ABCDEFGH121110987654321HGFEDCBADWG. NO. REV.E . C . N. REV DESCRIPTIONAPPROVAL

FM30/150/300 User’s Manual Board Layouts and Schematics Schematic Diagram: Motherboard (Sheet 2 of 3) DWG. NO.REV.HGFEDCBA12 345 67 89101112HGFEDCBA

Schematic Diagram: Motherboard (Sheet 3 of 3) DWG. NO.REV.HGFEDCBA12 345 67 89101112HGFEDCBA12 345 6 8 9 10 11 12SHEET OFSCALE : NONEPROJ NO.DWG .

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

FM30/150/300 User’s Manual Board Layouts and Schematics DWG. NO.REV.1234FDECBA1234FDECBASHEET OFSCALE : NONE PROJ NO.FILENAME:DWG . NO . REVTI

Illustration 6-9 FM Display Board 6-13 FM30/FM150/FM300 User’s Manual

FM30/150/300 User’s Manual Board Layouts and Schematics DWG. NO.REV.HGFEDCBA12 345 67 89101112HGFEDCBA12 345 6 8 9 10 11 12E . C . N. REV DESCRIPTIO

Illustration 6-10 FM Voltage Regulator 6-15 FM30/FM150/FM300 User’s Manual

FM30/150/300 User’s Manual Board Layouts and Schematics DWG. NO.REV.HGFEDCBA12 345 67 89101112HGFEDCBA12 345 6 89101112E . C . N. REV DESCRIPTIONAPP

Illustration 6-11 FM Power Regulator 6-17 FM30/FM150/FM300 User’s Manual

FM30/150/300 User’s Manual Board Layouts and Schematics DWG. NO. REV.1234 78ABCDEF1 234 678ABCEF5THESE DRAWINGS AND SPECIFICATIONS ARE THE PROPERTY

R19 Illustration 6-12 FM Power Amplifier FM150/FM300 6-19 FM30/FM150/FM300 User’s Manual

FM30/150/300 User’s Manual Board Layouts and Schematics DWG. NO. REV.1234 78ABCDEF1 234 678ABCEF5THESE DRAWINGS AND SPECIFICATIONS ARE THE PROPERTY

Illustration 6-13 FM Low Pass Filter #2 6-21 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 transmit

FM30/150/300 User’s Manual Board Layouts and Schematics EP DWG. NO. REV.1234 78ABCDEF1 234 678ABCEF5THESE DRAWINGS AND SPECIFICATIONS ARE THE PROPE

Illustration 6-14 FM RF Driver 6-23 FM30/FM150/FM300 User’s Manual

FM30/150/300 User’s Manual Board Layouts and Schematics DWG. NO. REV.1234 78ABCDEF1 234 678ABCEF5THESE DRAWINGS AND SPECIFICATIONS ARE THE PROPERTY

THESE DRAWINGS AND SPECIFICATIONS ARE THEPROPERTY OF INTERNATIONAL RADIO AND ELECTRONICS CORP.AND SHALL NOT BE REPRODUCED, COPIED OR USED AS THE BAS

FM30/150/300 User’s Manual Board Layouts and Schematics DWG. NO.REV.A201232-SCHHGFEDCBA12 345 67 89101112HGFEDCBA12 345 6 89101112E . C . N. REV DES

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

7.1 Service The product warranty (see opposite page) outlines our responsibility for defective products. Before returning a product for repair or re

Crown Broadcast Three Year Limited Product Warranty Summary Of Warranty Crown Broadcast IREC warrants its broadcast products to the ORIGINAL PURCHASE

The following lists describe the spare parts kit available for your transmitter. For the FM150 and FM300, use part number GFMSPARES. The following

Factory Service Instructions To obtain factory service, complete the bottom half of this page, include it with the unit, and ship to: International