Crown FM500 Transmitter

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Revision Control

Revision Print Date

Initial Release (K80713–9) June 1996

Revision 1 (101033–1) November 1996

Revision 2 (101033–2) August 1997

Revision 3 (900239–1) February 1998

Revision 4 (900239–1) October 1998

Revision 5 (901047-1) October 1999

Revision 6 (901047-2) May 2000

Revision 7 March 2002

Revision 8 February 2006

Important Notices

Portions of this document were originally copyrighted by Michael P. Axman in 1991.

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.

Sony and RCA are trademarks of their respective companies.

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 ContentsContentsContents

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 1.3 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 Remove PA Tray Spacers ...... 2–2 2.3 Power Connections ...... 2–3 2.4 Frequency (Channel) Selection ...... 2–5 2.4.1 Modulation Compensator ...... 2–6 2.4.2 RF Tuning Adjustments ...... 2–7 2.5 Receiver Frequency Selection ...... 2–7 2.6 RF Connections ...... 2–9 2.7 Audio Input Connections ...... 2–10 2.8 SCA Input Connections ...... 2–11 2.9 Composite Input Connection ...... 2–11 2.10 Audio Monitor Connections ...... 2–12 2.11 Pre-emphasis Selection ...... 2–12 2.12 Processor Bypass Option ...... 2–12 2.13 Program Input Fault Time-out ...... 2–13 2.14 Remote I/O Connector ...... 2–13

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 3.5 Processing Control ...... 3–6 3.6 Stereo-Mono Switch...... 3–6 3.4 Input Gain Switches ...... 3–6 3.7 RF Output Control ...... 3–7 3.8 Digital Multimeter ...... 3–7 3.9 Fault Indicators ...... 3–8 Section 4—Principles of Operation...... 4–1 4.1 Part Numbering ...... 4–2 4.2 Audio Processor Circuit Board ...... 4–3 4.3 Stereo Generator Circuit Board...... 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 Boards ...... 4–12 4.10 RF Driver ...... 4–12 4.11 RF Amplifier ...... 4–13 4.12 Chassis ...... 4–13 4.13 RF Output Filter & Reflectometer...... 4–14 4.15 Receiver Circuit Board Option ...... 4–14

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 Fine Adjustment ...... 5–2 5.2 Stereo Generator Adjustments ...... 5–3 5.2.1 Separation ...... 5–3 5.2.2 Composite Output ...... 5–3 5.2.3 19 kHz Level ...... 5–3 5.2.4 19 kHz Phase ...... 5–3 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 ...... 5–4 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 ...... 5–5 5.5 Motherboard Adjustments ...... 5–6 5.6 Display Modulation Calibration ...... 5–6 5.7 Voltage Regulator Adjustments ...... 5–6 5.8 Bias Set (RF Power Amplifier) ...... 5–6 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 ...... 5–10 5.20 38 kHz Subcarrier Suppression ...... 5–10 5.21 Additional Checks ...... 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 Appendix ...... A–1

Glossary ...... G–1

Index...... Index–1 I INFORMATION

Section 1—Getting Acquainted

This section provides a general description of the FM500 transmitter and introduces you to safety conventions used within this document. Review this material before installing or operating the transmitter.

Getting Acquainted 1–1 I 1.1 Your Transmitter

The FM500 is a member of a family of FM stereo broadcast transmitters. Crown transmitters are known for their modularity, ease-of-use, and reliability.

The modularity 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 four rotary switches), add an audio source, attach an antenna, connect AC 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 is 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.

Audio Input Fault Modulation Carrier 2 10 SWR Over High Band RF Power High Lock 100 SWR Expand Compress Input 90 2 20 ALC PA DC 80 PA DC Volts Wide Band PA Temp 70 PA DC Amps -6 60 PA Temperature Power 50 Supply DC Volts Stereo -12 +6 dB +12 dB 40 Voltmeter 30 -18 20 Low Mono RF Output Pilot Input Gain Processing

® FM500 FM BROADCAST TRANSMITTER

Illustration 1–1 FM500 Stereo Broadcast Transmitter

1–2 FM500 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, and satellator 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 FM500, for example, can generate up to 500 watts of RF output power.

Suffix letters describe the configuration. The FM500T, for example, designates a "transmitter" configuration. Since this is standard, it is what is described in the manual except where specified. In this configuration, the product includes the following modules (functions): ❑ audio processor ❑ stereo generator ❑ RF exciter ❑ metering ❑ low-pass filter

RF Exciter Stereo Generator Low-pass Filter

Metering Audio Processor

Audio Input Fault Modulation Carrier 2 10 SWR High Band RF Power Over High Lock SWR 100 Expand Compress Input 2 20 ALC 90 PA DC PA DC Volts 80 Wide Band PA Temp PA DC Amps 70 -6 PA Temperature 60 Power Supply DC Volts Stereo 50 -12 +6 dB +12 dB Voltmeter 40 30 -18 20 Low Mono RF Output Pilot Input Gain Processing

® FM500 FM BROADCAST TRANSMITTER

Illustration 1–2 Standard (Transmitter) Configuration

Getting Acquainted 1–3 I 1.2.1 Stand-Alone

In the standard configuration, the FM500 is an ideal stand-alone transmitter. When you add an audio source (monaural, L/R stereo, or composite signal), an antenna, and AC 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.

1.2.3 Booster

Also in the standard configuration, Crown transmitters have been used as booster transmitters. Booster applications typically involve certain geographic factors which prevent your system from broadcasting to the full coverage area allowable. For example, a mountain range might block your signal to a portion of your coverage area. Careful placement of a Crown transmitter, operating on the same frequency as your primary transmitter, can help you reach full coverage.

1.2.4 Exciter

In addition to the standard configuration, the FM500 is available in optional configurations to meet a variety of needs.

An "E" suffix, as in the FM500E, for example, represents an exciter-only configuration. In this configuration, the audio processor and stereo generator are not included. 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 FM500 User's Manual 1.2.5 Translator

A receiver configuration (FM500R, for example) takes an exciter configuration and adds receiver circuitry as well. This added feature makes the FM500 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.

Receiver Module RF IN Low-pass Filter RF Out (option)

Stereo Generator RF Exciter

Metering

® FM500 FM BROADCAST TRANSMITTER

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.

Getting Acquainted 1–5 I 1.2.6 Satellator

Another option is available for all configurations—an FSK Identifier (FSK IDer). This added feature enables the FM500 to transmit its call sign or operating frequency in Morse Code. 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).

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

Low-pass Filter RF Out

FSK IDer (option) Stereo Generator RF Exciter

Audio Processor Metering

® FM500 FM BROADCAST TRANSMITTER

Illustration 1–4 Transmitter with FSK IDer Option

1–6 FM500 User's Manual 1.3 Transmitter/Exciter Specifications

Frequency Range 87 MHz–108 MHz (65 MHz–73 MHz optionally available)

RF Power Output 100–550 watts (VSWR 1.5:1 or better) RF Output Impedance 50 Ω

Frequency Stability Meets FCC specifications from 0-50 degrees C

Audio Input Impedance 50 kΩ 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 15 kHz)

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

Stereo Separation

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

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

Crosstalk Main into sub, better than –40 dB

Sub into main, better than –40 dB

Stereo Pilot 19 kHz ±2 Hz, 9% modulation

Subcarrier Suppresion 50 dB below ±75 kHz deviation

FM S/N Ratio (FM noise) Complete transmitter Better than –60 dB

Exciter only Better than –70 dB

Getting Acquainted 1–7 I AM S/N Ratio Asynchronous and synchronous noise better than NAB recommendations

RF Bandwidth ±120 kHz, better than –35 dB ±240 kHz, better than –45 dB

RF Spurious Products Better than –70 dB

Operating Environment Temperature (0–50o C)

Humidity (0–80% at 20o C)

Maximum Altitude (3,000 meters; 9843 feet)

AC Power 100, 120, 220, or 240 volts (+10%/–15%); 50/60 Hz

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

Dimensions 17.8 x 41.9 x 44.5 cm

(7.0 x 16.5 x 17.5 inches)

Weight 29.5 kg (65 lbs); 31.8 kg (70 lbs) shipping weight

1–8 FM500 User's Manual 1.4 Receiver Specifications

Monaural Sensitivity (demodulated, de-emphasized) 3.5 µV for signal-to-noise > 50 dB 12.6 µV for signal-to-noise > 60 dB

Stereo Sensitivity (19–kHz pilot frequency added) 2.8 µV for signal-to-noise > 40 dB 8 µV for signal-to-noise > 50 dB 31 µV for signal-to-noise > 60 dB

Connector Standard type N, 50 Ω

Shipping Weight 1 lb

Getting Acquainted 1–9 I 1.5 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.

1.5.1 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.

Type of Hazard WARNING Severe shock hazard!

Turn power off and Pictorial Indication wait approximately 1 Explanation of of Hazard minute for capacitors Hazard to discharge before handling them.

Illustration 1–5 Sample Hazard Alert

1–10 FM500 User's Manual ®

Section 2—Installation

This section provides important guidelines for installing your transmitter. Review this information carefully for proper installation.

Installation 2–1 CAUTION Possible equipment damage! Before operating the transmitter for the first time, check for the proper AC line voltage setting and frequency selection as described in sections 2.3 and 2.4.

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 Remove PA Tray Spacers

The Crown FM 500 is shipped with spacers between the PA tray and the transmitter back panel. The spacers prevent damage to internal contacts during shipping. Remove and save the spacers and screws before installing the FM500. #8 #8

#6 Illustration 2-1 FM 500 PA Tray Mounting Screws 1. Remove screws and spacers from five locations. 2. Firmly push the PA tray into the FM 500 until the PA tray panel touches the back panel. 3. Locate the bag labeled 500 Hardware. Install four #8 screws and washers and one number #6 screw and washer. See photo for locations.

2–2 FM500 User's Manual 2.3 Power Connections

The FM500 operates on 100, 120, 220, or 240 volts AC (50 or 60 Hz; single phase). As shipped (factory default settings), the FM500 operates on 120 volts at 60 Hz.

If you are operating the transmitter at 120 volts you do not need to make any changes. To operate the FM500 at 100, 220, or 240 volts, a few changes are necessary.

To change the voltage setting, follow these steps: 1. Disconnect the power cord if it is attached. 2. To set the input voltage for 100 volts, skip to step 7. 3. Open the cover of the power connector assembly using a small, flat blade screwdriver. See Illustration 2–2. 4. Insert the screwdriver into the top slot of the voltage selection assembly (red) and pry out the assembly from the power connector. 5. If you are setting the input voltage for 220 or 240 volts, replace the installed fuses with 12 amp fuses (included in your package). See Illustration 2–3. 6. Replace the red fuse assembly so that the "230V" setting appears right side up in the window. Close the assembly window.

115V

115V 230V

Illustration 2–2 Illustration 2–3 Opening the Power Connector Cover Removing the Voltage Selection (red) Assembly

Installation 2–3 7. Turn the transmitter upside down and remove the bottom cover. Note: The front panel filter grill must be removed to expose all of the bottom

Power Distribution Board

front of transmitter

Illustration 2–4 Underside of Transmitter—Bottom Cover Removed

cover screws for bottom cover removal and installation. 8. Locate the power distribution circuit board on the left side next to the large transformer cover. See Illustration 2–4. 9. For 100 or 220 volt operation, change the jumper setting of P1 to the 100/ 220 V setting. 10. For 220 or 240 volt operation, • remove the jumper connecting P6 and P7. • remove the jumper connecting P4 and P5. • use a jumper to connect P5 and P6. 11. Replace the bottom cover, and the front grill. 12. Connect the AC power cord. For your reference, use 12 amp fuses for 220 or 240 volt operation and 20 amp fuses for 100 or 120 volt operation.

2–4 FM500 User's Manual 2.4 Frequency (Channel) Selection

You may select an operating frequency of 87 to 108 MHz in the FM broadcast band with 100 kHz channel spacing (10 kHz spacing is optional with the addition of a fifth rotary selector switch).

To adjust the operating frequency, follow these steps: 1. Remove the top cover by removing 15 screws. 2. Locate the RF Exciter board and identify the frequency selector switches which will be used to change the setting. See Illustrations 2–5 and 2–6.

Modulation Trim-pot Frequency Selection Rotary Switches RF Exciter

® FM500 FM BROADCAST TRANSMITTER

Illustration 2–5 Top Cover Removed

MEGAHERTZ .1 .01 Illustration 2–6 RF Exciter Board Frequency Selector Switches

Installation 2–5 3. 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.

= 88.1 MHz

= 107.9 MHz

Illustration 2–7 Two Sample Frequency Selections

4. If you have the receiver option, proceed to section 2.5 to set the incoming frequency. Otherwise, replace the top cover.

2.4.1 Modulation Compensator

The Modulation trim-potentiometer (see illustration 2–8) compensates for slight variations in deviation sensitivity with frequency. Set the trim-pot dial according to the following graph:

Modulation Compensation Pot Setting

0 75 80 85 90 95 100 105 110 Frequency (MHz)

Illustration 2–8 Modulation Compensator Settings

These compensator settings are approximate. Each mark on the potentiometer represents about 1.8% modulation compensation. For more exact settings, refer to section 5.2.2.

2–6 FM500 User's Manual 2.4.2 RF Tuning Adjustments

All the RF stages are broadband to cover the 88 to 108 MHz broadcast band. The RF amplifier stages require no tuning.

2.5 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). 2. Use the table on the following pages to set the switches for the desired incoming frequency. 3. After setting the frequency, return to section 2.3.1 to set the modulation compensator.

Frequency Selection Switches SW1 & SW2 RF IN

StereoReceiver GeneratorModule RF Exciter

® FM500 FM BROADCAST TRANSMITTER

Illustration 2–8 Receiver Module Switches

Installation 2–7 Frequency SW1 SW2 Frequency SW1 SW2 Frequency SW1 SW2 Frequency SW1 SW2 87.9 0 0 93.0 99 98.0 B2 103.0 CB 88.0 80 93.1 1 A 98.1 3 3 103.1 4 C 88.1 0 1 93.2 9 A 98.2 B 3 103.2 C C 88.2 8 1 93.3 1 B 98.3 3 4 103.3 4 D 88.3 0 2 93.4 9 B 98.4 B 4 103.4 C D 88.4 8 2 93.5 1 C 98.5 3 5 103.5 4 E 88.5 0 3 93.6 9 C 98.6 B 5 103.6 C E 88.6 8 3 93.7 1 D 98.7 3 6 103.7 4 F 88.7 0 4 93.8 9 D 98.8 B 6 103.8 C F 88.8 8 4 93.9 1 E 98.9 3 7 103.9 5 0 88.9 0 5 94.0 9E 99.0 B7 104.0 D0 89.0 85 94.1 1 F 99.1 3 8 104.1 5 1 89.1 0 6 94.2 9 F 99.2 B 8 104.2 D 1 89.2 8 6 94.3 2 0 99.3 3 9 104.3 5 2 89.3 0 7 94.4 A 0 99.4 B 9 104.4 D 2 89.4 8 7 94.5 2 1 99.5 3 A 104.5 5 3 89.5 0 8 94.6 A 1 99.6 B A 104.6 D 3 89.6 8 8 94.7 2 2 99.7 3 B 104.7 5 4 89.7 0 9 94.8 A 2 99.8 B B 104.8 D 4 89.8 8 9 94.9 2 3 99.9 3 C 104.9 5 5 89.9 0 A 95.0 A3 100.0 BC 105.0 D5 90.0 8A 95.1 2 4 100.1 3 D 105.1 5 6 90.1 0 B 95.2 A 4 100.2 B D 105.2 D 6 90.2 8 B 95.3 2 5 100.3 3 E 105.3 5 7 90.3 0 C 95.4 A 5 100.4 B E 105.4 D 7 90.4 8 C 95.5 2 6 100.5 3 F 105.5 5 8 90.5 0 D 95.6 A 6 100.6 B F 105.6 D 8 90.6 8 D 95.7 2 7 100.7 4 0 105.7 5 9 90.7 0 E 95.8 A 7 100.8 C 0 105.8 D 9 90.8 8 E 95.9 2 8 100.9 4 1 105.9 5 A 90.9 0 F 96.0 A8 101.0 C1 106.0 DA 91.0 8F 96.1 2 9 101.1 4 2 106.1 5 B 91.1 1 0 96.2 A 9 101.2 C 2 106.2 D B 91.2 9 0 96.3 2 A 101.3 4 3 106.3 5 C 91.3 1 1 96.4 A A 101.4 C 3 106.4 D C 91.4 9 1 96.5 2 B 101.5 4 4 106.5 5 D 91.5 1 2 96.6 A B 101.6 C 4 106.6 D D 91.6 9 2 96.7 2 C 101.7 4 5 106.7 5 E 91.7 1 3 96.8 A C 101.8 C 5 106.8 D E 91.8 9 3 96.9 2 D 101.9 4 6 106.9 5 F 91.9 1 4 97.0 AD 102.0 C6 107.0 DF 92.0 94 97.1 2 E 102.1 4 7 107.1 6 0 92.1 1 5 97.2 A E 102.2 C 7 107.2 E 0 92.2 9 5 97.3 2 F 102.3 4 8 107.3 6 1 92.3 1 6 97.4 A F 102.4 C 8 107.4 E 1 92.4 9 6 97.5 3 0 102.5 4 9 107.5 6 2 92.5 1 7 97.6 B 0 102.6 C 9 107.6 E 2 92.6 9 7 97.7 3 1 102.7 4 A 107.7 6 3 92.7 1 8 97.8 B 1 102.8 C A 107.8 E 3 92.8 9 8 97.9 3 2 102.9 4 B 107.9 6 4 92.9 1 9 108.0 E4 Table 2–1 Receiver Frequency Selection

2–8 FM500 User's Manual 2.6 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. WARNING Severe shock hazard!

Do not touch the inner portion of the RF output connector when transmitter power is on.

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.

RF Output Connector RFInput Connector (receiver option only)

RF Output Monitor 115V

Illustration 2–10 RF Connections

Installation 2–9 2.7 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.

SCA IN COMPOSITE IN MONITOR RIGHT LEFT/MONO

R L

REMOTE I/O

1 23

Audio Inputs

Illustration 2-10 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, install resistors on the 8–pin DIP socket on the motherboard (socket A501 located between the XLR connectors). See the motherboard schematic, on page 6–13.

2–10 FM500 User's Manual 2.8 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.

SCA IN COMPOSITE IN MONITOR RIGHT LEFT/MONO

R L

REMOTE I/O

1 23

SCA Inputs (BNC) Connectors

Illustration 2–12 SCA Input Connectors

2.9 Composite Input Connection

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. See Section 2.12 on the next page for caution in using the bypass option.

Input sensitivity is approximately 3.5–volt P-P for 75 kHz deviation. 1. Enable the Composite Input by grounding pin 9 of the Remote I/O connector (see Illustration 2–15). 2. Connect the composite signal using the Composite In BNC connector.

Installation 2–11 SCA IN COMPOSITE IN MONITOR RIGHT LEFT/MONO

R L

REMOTE I/O

1 23

Composite Input Audio Monitor (BNC) Connector (RCA) Jacks

Illustration 2–13 Composite In and Audio Monitor Connections 2.10 Audio Monitor Connections Processed, de-emphasized samples of the left and right audio inputs to the stereo generator are available at the Monitor jacks on the rear panel. The signals are suitable for feeding a studio monitor and for doing audio testing. De-emphasis is normally set for 75 µsec; set to 50 µsec by moving jumpers, JP203 and JP204, on the Stereo Generator board.

2.11 Pre-emphasis Selection Select the pre-emphasis curve (75 µsec, 50 µsec, 25 µsec, or Flat) by jumpering the appropriate pins of header JP1 on the audio processor board. If you change the pre-emphasis, change the de-emphasis jumpers JP203 and JP204 on the Stereo Generator board to match.

2.12 Processor Bypass Option You may bypass the audio processor in order to feed the left and right (pre- emphasized) audio directly to the stereo generator. The Normal-Bypass slide switch is near the left-rear corner of the motherboard. If the audio source is already processed and you do not desire further processing, use the Normal mode but turn the Processing control (on the front panel) to “0.” (See also section 3.5.) CAUTION In the BYPASS position, the pre-emphasis circuits and the filters that protect the pilot and stereo subcarrier are bypassed. As a result, the occupied bandwidth specifications of the transmitter could be compromised. The 15–Hz high-pass filters are also bypassed which may mean that modulation with frequencies below 10 Hz could cause the frequency synthesizer to unlock.

2–12 FM500 User's Manual 2.13 Program Input Fault Time-out

You can enable an automatic turn-off of the carrier in the event of program failure. To enable this option, see the table on the next page. The time between program failure and carrier turn-off is set by a jumper (JP701) on the voltage regulator board (see Illustration 6–4 for board location). Jumper pins 1 and 2 (the two pins closest to the edge of the board) for a delay of approximately 30 seconds; pins 3 and 4 for a 2–minute delay; pins 5 and 6 for a 4–minute delay, and pins 7 and 8 for an 8–minute delay.

2.14 Remote I/O Connector

Remote control and remote metering of the transmitter is made possible through a 15–pin, D-sub connector on the rear panel. (No connections are required for normal operation.)

SCA IN COMPOSITE IN MONITOR RIGHT LEFT/MONO

R L

REMOTE I/O

1 23 Remote I/O

Illustration 2–14 Remote I/O Connector

The following table summarizes the Remote I/O pin connections.

Installation 2–13 Pin Number Function

1 Ground

2 (no connection)

3 Composite Out (sample of stereo generator output)

4 FSK In (Normally high; pull low to shift carrier frequency approximately 7.5 kHz. Connect to open collector or relay contacts of user-supplied FSK keyer.)

5 /Auto Carrier Off (Pull low to enable automatic turnoff of carrier with program failure.)

6 Meter Battery (unregulated DC volts; 5 volts = 50 VDC)

7 Meter RF Watts (1 volt = 100 watts)

8 Meter PA Volts (5 volts = 50 VDC)

9 /Ext. Enable (Pull low to disable internal stereo generator and enable External Composite Input.)

10 a) 38 kHz Out (From stereo generator for power supply synchronization.)

b) For transmitters equipped with tuner option, this pin becomes the right audio output for an 8–ohm monitor speaker. 38kHZ Out is disabled.

11 ALC

12 /Carrier Off (pull low to turn carrier off.)

13 Fault Summary (line goes high if any fault light is activated.)

14 Meter PA Temperature (5 volts = 100 degrees C.)

15 Meter PA Current (1 volt = 10 amperes DC.)

Table 2–3 Remote I/O Connections

8 1

15 9 Illustration 2–15 Remote I/O Connector (outside view)

2–14 FM500 User's Manual Section 3—Operation

This section provides general operating parameters of your transmitter and a detailed description of its 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 transmitter. More detailed information follows.

CAUTION Possible equipment damage! Before operating the transmitter for the first time, check for the proper AC line voltage setting and frequency selection as described in sections 2.3 and 2.4.

1. Turn on the main power switch.

Carrier Switch

Fault Modulation Carrier

SWR Over Lock 100 Input 90 PA DC 80 PA Temp 70

60 Power Stereo 50 40 30 20 Mono RF Output Pilot FM500 FM BROADCAST TRANSMITTER

Power Switch

Illustration 3–1 Front Panel Power Switches

2. Verify the following: a. The bottom cooling fans runs continuously. b. The Lock Fault indicator flashes for approximately 5 seconds, then goes off. 4. Set the Input Gain switches for mid-scale wideband gain reduction on an average program level (see section 3.4). 5. Set the Processing control (see section 3.5; normal setting is “50”). 6. Set the Stereo-Mono switch to Stereo (see section 3.6). 7. Turn on the Carrier switch.

3–2 FM500 User's Manual 8. Check the following parameters on the front panel multimeter: a. RF Power should be 500–550 watts. b. SWR should be less than 1.25 (A reading greater than 1.25 indicates an antenna mismatch). c. ALC should be between 4.00 and 6.00 volts. d. PA DC Volts should be 46–56 volts. (Varies with antenna match, power, and frequency.) e. PA DC Amperes should be 12–16 amps. (Varies with antenna match, power, and frequency.) f. PA Temperature should initially read 20–35 degrees C (room temperature). After one hour the reading should be 35–50 degrees C. g. Supply DC Volts should display a typical reading of 65–70 V with the carrier on and 80–85 V with the carrier off h. Voltmeter should be reading 0.0.

The remainder of this section describes the functions of the front panel indicators and switches.

Operation 3–3 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. Electrically, the DC breaker is located immediately after diodes which isolate the DC and AC power supplies.

3.2.2 Power Switch

The main on/off power switch controls both the 120/240 VAC and the DC battery power input.

3.2.3 Carrier Switch

This switch controls power to the RF amplifiers and supplies a logic high to the voltage regulator board, which enables the supply for the RF driver. In addition, the Carrier Switch controls the operating voltage needed by the switching power regulator.

A "Lock Fault" or a low pin 12 (/Carrier Off) on the Remote I/O connector will hold the carrier off. (See section 2.12.)

Carrier Switch

Fault Modulation Carrier

SWR Over Lock 100 Input 90 PA DC 80 PA Temp 70

60 Power Stereo 50 40 30 20 Mono RF Output Pilot FM500 FM BROADCAST TRANSMITTER

Power Switch Illustration 3–2 Front Panel Power Switches

3–4 FM500 User's Manual 3.3 Front Panel Bar-Dot Displays

Bar-dot LEDs show audio input levels, wideband and highband audio gain control, and modulation percentage. Resolution for the gain control and modulation displays is increased over a conventional bar-graph display using dither enhancement which modulates the brightness of the LED to give the effect of a fade from dot to dot. (See section 4.7.)

3.3.1 Audio Processor Input

Two vertical, moving-dot displays for the left and right channels indicate the relative audio levels, in 3 dB steps, at the input of the audio processor. Under normal operating conditions, the left and right Audio Processor indicators will be active, indicating the relative audio input level after the Input Gain switches. During program pauses, the red Low LED will light.

With the receiver module option installed, the audio processor indicators are disabled.

3.3.2 Highband and Wideband Display

During audio processing, the moving-dot displays indicate the amount of gain control for broadband (Wide) and pre-emphasized (High) audio. These indicators are disabled if the receiver module option is installed.

As long as program material causes activity of the Wideband green indicators, determined by the program source level and Input Gain switches, the transmitter will be fully modulated. (See section 3.4.)

The Wideband indicator shows short-term “syllabic-rate” expansion and gain reduction around a long-term (several seconds) average gain set.

Program material and the setting of the Processing control determine the magnitude of the short-term expansion and compression (the rapid left and right movement of the green light).

High-frequency program content affects the activity of the Highband indicator. With 75–µsec pre-emphasis, Highband processing begins at about 2 kHz and increases as the audio frequency increases. Some programs, especially speech, may show no activity while some music programs may show a great deal of activity.

3.3.3 Modulation Display

A 10–segment, vertical peak-and-hold, bar graph displays the peak modulation percentage. A reading of “100” coincides with 75 kHz deviation. The display holds briefly (about 0.1 seconds) after the peak. The “Pilot” indicator illuminates when the transmitter is in the stereo mode.

To verify the actual (or more precise) modulation percentage, connect a certified modulation monitor to the RF monitor jack on the rear panel.

Operation 3–5 3.4 Input Gain Switches

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

Nominal Input Switches Sensitivity +6 dB +12 dB +10 dBm Down Down +4 dBm Up Down -2 dBm Down Up -8 dBm Up Up

Table 3–1 Input Gain Switches

Find, experimentally, the combination of Input Gain switch settings that will bring the Wideband gain-reduction indicator to mid scale for “normal” level program material. The audio processor will accommodate a fairly wide range of input levels with no degradation of audio quality.

3.5 Processing Control

Two factors contribute to the setting of the Processing control: program material and personal taste. For most program material, a setting in the range of 40 to 70 provides good program density. For the classical music purist, who might prefer preservation of music dynamics over density, 10 to 40 is a good range. The audio will be heavily processed in the 70 to 100 range.

If the program source is already well processed, as might be the case with a satellite feed, set the Processing to “0” or “10”.

3.6 Stereo-Mono Switch

The Stereo-Mono slide switch selects the transmission mode. In Mono, feed audio only to the left channel. Although right-channel audio will not be heard as audio modulation, it will affect the audio processing.

3–6 FM500 User's Manual 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 coaxial line to the antenna. You may also use the RF power reading on the digital multimeter.

The control sets the RF output voltage. Actual RF output power varies as the approximate square of the relative setting of the control. For example, a setting of “50” is approximately 1/4 full power. Operation below 100 watts is not recommended as instability can occur which could damage the transmitter.

CAUTION

Possible equipment damage!

Operation below 100 watts can cause oscillations and other problems that could damage the transmitter.

3.8 Digital Multimeter

The four-digit numeric display in the center of the front panel provides information on transmitter operation. Use the “Up” and “down” push-buttons to select one of the following parameters. A green LED indicates the one selected.

Digital Multimeter Multimeter Functions Multimeter Push-buttons

® FM500 FM BROADCAST TRANSMITTER

Illustration 3–3 Digital Multimeter

RF Power—Actually reads RF voltage squared, so the accuracy can be affected by VSWR (Voltage Standing-Wave Ratio). See section 5.4 for calibration. Requires calibration with the RF reflectometer being used.

SWR—Direct reading of the antenna standing-wave ratio (the ratio of the desired load impedance, 50 ohms, to actual load).

Operation 3–7 ALC—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 4 to 5.5 volts. The ALC voltage will be reduced during PA DC overcurrent, SWR, or LOCK fault conditions.

PA DC Volts—Supply voltage of the RF power amplifier.

PA DC Amps—Transistor drain current for the RF power amplifier.

PA DC Temperature—Temperature of the RF power amplifier heatsink in degrees C.

Supply DC Volts—Unregulated DC voltage at the input of the voltage regulators. For battery operation, this reading is the battery voltage minus a diode drop.

Voltmeter—Reads the voltage at a test point located on the front edge of the motherboard. A test lead connected to this point can be used for making voltage measurements in the transmitter. The test point is intended as a servicing aid; an alternative to an external test meter. Remember that the accuracy is only as good as the reference voltage used by the metering circuit. Servicing a fault affected by the reference affects the Voltmeter reading. The metering scale is 0 to 199.9 volts.

3.9 Fault Indicators

Faults are indicated by a blinking red light as follows:

SWR—Load VSWR exceeds 1.5:1. ALC voltage is reduced to limit the reflected RF power.

Lock—Frequency synthesizer phase-lock loop is unlocked. This indicator normally blinks for about five seconds at power turn-on. Whenever this light is blinking, supply voltages will be inhibited for the RF driver stage as well as for the RF power amplifier.

Input—The automatic carrier-off circuit is enabled (see sections 2.11 and 2.12) and the absence of a program input signal has exceeded the preset time. (The circuit treats white or pink noise as an absence of a program.)

PA DC—Power supply current for the RF power output amplifier is at the preset limit. ALC voltage has been reduced, reducing the PA supply voltage to hold supply current to the preset limit.

PA Temp—PA heatsink temperature has reached 80–85° C (178–185° F).

At about 83° C (181°F), ALC voltage begins to decrease, reducing the PA supply voltage to prevent a further increase in temperature. By 85° C (185° F), the PA will be fully cut off.

3–8 FM500 User's Manual erono due persone c ndo, he ab la matita ci insegna mo bia o con a non sto no end pa ue on ha la riv rlar n q ce che n dispozion sc e i si di e do a , erono due persone ch no fa m ondo e ab , u rlo. m bia rse non c'e nulla nel M sto no fo e che mond ue on ha la o ch o re n q ce che n dispozion m ale i si di e do icia di no fa e d matita ci inseg , u rlo. s con la na a no rse M ndo n p fo ive arla scr re a erono due persone c m ndo, he ab mo bia 'e nu sto no che non c lla nel mon ue on ha la che do r n q ce che n dispozion mo eal i si di e do cia e d no fa di i , u rlo. se la matita ci insegna a rse e non c'e nulla nel m M o con non fo he ch ondo end par o c rea criv lare iam le s ic di ma e non c'e nulla nel m e d matita ci inseg he ch ondo s con la na a n o c rea do on p iam le ven arla ic di cri re e d matita ci inseg a s s con la na a no m ndo n p ive arla scr re ma matita ci inseg con la na a no ndo n p ive arla scr re a rono due persone m ndo, e che a mo bbia sto no ue q che non ha la dispozi in i dice one d o s o fa , un rlo se on c'e nulla n . M for e che n el mon ch do re mo ale icia di e d matita ci inseg s con la na a no ndo n p ive arla scr re ma

Section 4—Principles of Operation

This section discusses the circuit principles upon which the transmitter functions. This information is not needed for day-to- day operation of the transmitter but may be useful for advanced users and service personnel.

Principles of Operation 4–1 sto mond n que o, scrive do con in e, uno si dice ma esto mond ors iamo ch qu o, f dic e in e, uno si dice se rivendo c ors a sc on f m uesto mondo o n q uno si d , diciam che i se, ice e end for iciamo che s scriv o con e d ma amo ch s scrivendo co dici e a n se rivendo m a sc con en m scriv do con ma esto mond qu no s o, in se, u i dice for iciamo che e d en s scriv do con ma 4.1 Part Numbering

As this section refers to individual components, you should be familiar with the part numbering scheme used. Although parts on the various circuit boards and circuit board drawings may be marked with identical reference numbers, each component in the transmitter has a unique part reference number.

The circuit boards and component placement drawings use designators such as “R1”, “R2”, and “C1.” These numbers represent only a portion of the full part numbers (as shown on the schematic). To find the full number, refer to the chart below. R401, for instance, is marked “R1” on the Metering board and on its component placement drawing.

Circuit Name Part numbers

Audio Processor 0-199

Stereo Generator 200’s

RF Exciter/Synthesizer 300’s

Metering/Protection 400’s

Motherboard 500’s

Display 600’s

Voltage Regulator 700’s

Power Regulator 800’s

RF Predriver 900’s

Chassis Wiring 1000's

RF Power Amplifier 1100's

RF Low-Pass Filter 1200's

Illustration 4–1 Component Part Numbering

4–2 FM500 User's Manual 4.2 Audio Processor Circuit Board

The audio processor board provides the audio control functions of a compressor, limiter, and expander. Illustration 6–5 and accompanying schematic may be useful to you during this discussion.

Audio Processor

® FM500 FM BROADCAST TRANSMITTER

Illustration 4–2 Audio Processor Board

This board also contains the pre-emphasis networks. Reference numbers are for the left channel. Where there is a right-channel counterpart, references are in parenthesis. One processor circuit, the eighth-order elliptical filter, is located on the stereo generator board.

Audio input from the XLR connector on the rear panel of the transmitter goes to differential-input amplifier, U1A (U2A).

Binary data on the +6 dB and +12 dB control lines sets the gain of inverting amplifier U1B (U2B). Analog switch, U3, selects one of four feedback points in 6 dB steps.

The output of U1B (U2B) goes to an eighth-order, elliptical, switched-capacitor, low-pass, 15.2 kHz filter. The filter finds its home on the stereo generator board to take advantage of the ground plane and proximity to the 1.52 MHz clock.

The circuit associated with U4B (U4A), along with R22/C8 (R58/C20), form third-order, low-pass filtering, attenuating audio products below 30 Hz.

The output level of analog multiplier U5 (U6) is the product of the audio signal at pin 13 and the DC voltage difference between pins 7 and 9. At full gain (no gain reduction) this difference will be 10 volts DC.

Principles of Operation 4–3 sto mond n que o, scrive do con in e, uno si dice ma esto mond ors iamo ch qu o, f dic e in e, uno si dice se rivendo c ors a sc on f m uesto mondo o n q uno si d , diciam che i se, ice e end for iciamo che s scriv o con e d ma amo ch s scrivendo co dici e a n se rivendo m a sc con en m scriv do con ma esto mond qu no s o, in se, u i dice for iciamo che e d en s scriv do con ma When either the positive or negative peaks of the output of U5 (U6) exceeds the gain-reduction threshold, U13A generates DC bias, producing broadband gain reduction. Q5 is a precision-matched transistor pair. Q5 and U13B form a log converter, so that a given voltage change produces a given change in gain control dB of U5 (U6). The log conversion ensures uniform level-processing characteristics well beyond the 20 dB control range. The log conversion has an additional benefit; it allows a display of gain control on a linear scale with even distribution of dB.

Q1 (Q2) is a recover/expansion gate with a threshold about 18 dB below the normal program level. The amount of short-term expansion and gain reduction is controlled by R650, located on the front panel display board. (See section 3.5.)

Pre-emphasis, in microseconds, is the product of the capacitance of C10 (C22), multiplied by the gain of U8 (U9), times the value of R31 (R67). For a 75 µsecond pre-emphasis, the gain of U8 (U9) will be about 1.11. Select the pre-emphasis curve (75 µsec, 50 µsec, 25 µsec, or Flat) by jumpering the appropriate pins on header JP1. Use trim pot R29 (R65) to make fine adjustments to the pre-emphasis. (See section 5.1.)

For highband processing, the peak output of U10B is detected and gain-reduction bias is generated, as with the broadband processor. The highband processing, however, shifts the pre-emphasis curve rather than affecting overall gain.

Peak audio voltages are compared to a plus and minus 5 volt reference, U17 and U18. This same reference voltage is used by the stereo generator, metering, and display boards.

For an explanation of on-board adjustments see section 5.1.

4.3 Stereo Generator Circuit Board

The stereo generator board (see Illustration 4–3) generates a composite stereo signal from left and right-channel audio inputs. The component side of the board is mostly a ground plane. Once again, the eighth-order, 15.2 kHz, elliptical, low-pass filters (U201 and U202) are on this board, but belong to the audio processor.

Illustration 6–6 and accompanying schematic complement this discussion.

U207A and Y201 comprise a 7.6 MHz crystal oscillator from which the 19 kHz and 38 kHz subcarriers are digitally synthesized. U207F is a buffer. The 7.6 MHz is divided by 5 in U208A to provide 1.52 MHz at pin 6, used by filters U201 and U202. 3.8 MHz, 1.9 MHz, and 304 kHz are also derived from dividers in U208.

Exclusive-OR gates, U210A and U210B, provide a stepped approximation of a 38 kHz sine wave—a scheme described in the CMOS Cookbook by Don Lancaster (Howard W. Sams &. Co., Inc., Indianapolis, IN, 1978).

With the resistor ratios used, the synthesized sine wave has very little harmonic energy below the 7th harmonic. U210C and D generate the 19 kHz pilot subcarrier. U211 is a dual, switched-capacitor filter, configured as second-order, low-pass filters,

4–4 FM500 User's Manual Stereo Generator

® FM500 FM BROADCAST TRANSMITTER

Illustration 4–3 Stereo Generator Board

each with a Q of 5. The 38 kHz and 19 kHz outputs of pins 1 and 20, respectively, are fairly pure sine waves. Harmonic distortion products are better than 66 dB down—THD of less than 0.05%.

U212 is a precision, four-quadrant, analog multiplier. The output of U212 is the product of 38 kHz applied to the “X” input and the difference of left and right audio (L-R signal) applied to the “Y” input. The resulting output is a double sideband, suppressed carrier—the L-R subcarrier.

The SCA subcarrier, the left, right, and left-minus-right subcarriers, and the 19 kHz pilot subcarrier are combined into the composite stereo signal by summing amplifier U206B.

Analog switch U205, at the input of U206B, provides switching of left and right audio for stereo and mono modes. In the mono mode, right channel audio is disabled, and the left channel audio is increased from 45% modulation to 100%.

MON L and MON R outputs go to the AF Monitor jacks on the rear panel. R208+R210 (R220+R222) and C207 (C211) comprise a 75 µsec de-emphasis network. Processed, de-emphasized (75 µsec) samples of the stereo generator input signals are used for a studio monitor and for audio testing. Option jumpers JP203 (JP204) allow you to select 50 µsec.

VR201 and VR202 supply +6 volts and –6 volts, respectively. A 5 volt reference from the audio processor board supplies the subcarrier generators.

For an explanation of on-board adjustments see section 5.2.

Principles of Operation 4–5 sto mond n que o, scrive do con in e, uno si dice ma esto mond ors iamo ch qu o, f dic e in e, uno si dice se rivendo c ors a sc on f m uesto mondo o n q uno si d , diciam che i se, ice e end for iciamo che s scriv o con e d ma amo ch s scrivendo co dici e a n se rivendo m a sc con en m scriv do con ma esto mond qu no s o, in se, u i dice for iciamo che e d en s scriv do con ma 4.4 RF Exciter Circuit Board

This board is also known as the Frequency Synthesizer board. The entire component side of the board is a ground plane. Rotary switches along the front edge of the board establish the operating frequency. The VCO (voltage-controlled oscillator) circuitry is inside a shielded cover.

Illustration 6–7 and accompanying schematic can be used as reference in this discussion. The following theory may apply to previous versions of the exciter board, but it is typical of the operation of the current board which has the latest technological improvements.

VCO, VCO61, operates at the synthesizer output frequency of 87 MHz to 108 MHz. The frequency is controlled by voltage-variable capacitors DV71 and DV72. U7A and U7B form an active filter to supply clean DC to the drain of Q71. They also serve as a common-base RF amplifier for Q71. A71 and A1 are hybrid RF amplifiers to provide buffering and gain.

A sample of the RF from the VCO goes to the input of A2. A2 amplifies the signal and feeds it back to the synthesizer IC, U6. This signal, available at pin 4 of U6, may be used with a high frequency receiver for deviation and frequency measurements. (See sections 5.2 and 5.3.)

U6 is a phase-locked-loop frequency synthesizer IC. The 10.24 MHz from the crystal oscillator is used by U6, along with ICs U1 through U3 and the frequency selector switches, to generate the frequencies of the transmitter.

RF Exciter

® FM500 FM BROADCAST TRANSMITTER

Illustration 4–4 RF Exciter Board

4–6 FM500 User's Manual U6 is programmed with the four or five rotary switches. The binary output of the 0.1 MHz switch programs the “A” counter directly. BCD data from the 100’s, tens, and units rotary switches is converted to binary data by U3 to set the “N” counter. An optional fifth digit rotary switch for 10kHz spacing is available.

U5C is a differential amplifier and filter for the error signal. Audio that is out of phase with that appearing on the error voltage is introduced by U5A, allowing for greater loop bandwidth with less degradation of the low-frequency audio response. U5D is an integrator. U5B is a VCO input voltage clamp.

DV71 and DV72 are hyper-abrupt varactor tuning diodes with a square-law capacitance vs DC voltage curve, giving a straight-line frequency vs voltage curve in a LC oscillator where the varactors are the dominant source of capacitance.

Lock and unlock status signals are available at the outputs of U4E and U4F, respectively. Modulation is introduced to the VCO through R17 and R71 to R75. About 4.1 millivolts across R75 produces 75 kHz deviation.

An FSK signal (used for automatic identification of FM repeaters) shifts the frequencies of the 10.24 MHz crystal reference and the VCO. With keying, diodes D9 and D10, are reverse biased, increasing the crystal reference frequency. At the same time, current through R72 increases the VCO frequency. See section 5.3.4.

Principles of Operation 4–7 sto mond n que o, scrive do con in e, uno si dice ma esto mond ors iamo ch qu o, f dic e in e, uno si dice se rivendo c ors a sc on f m uesto mondo o n q uno si d , diciam che i se, ice e end for iciamo che s scriv o con e d ma amo ch s scrivendo co dici e a n se rivendo m a sc con en m scriv do con ma esto mond qu no s o, in se, u i dice for iciamo che e d en s scriv do con ma 4.5 Metering Circuit Board

The ALC and metering circuitry is on the metering board (see Illustration 4–4). This board processes information for the RF and DC metering, and produces ALC (RF level-control) bias. It also provides reference and input voltages for the digital panel meter, voltages for remote metering, fan control, and drive for the front-panel fault indicators.

Illustration 6–8 and accompanying schematic complement this discussion.

PA voltage and current come from a metering shunt on the power regulator board. The PAI input is a current proportional to PA current; R405 converts the current to voltage used for metering and control. A voltage divider from the PAV line is used for DC voltage metering.

Metering

® FM500 FM BROADCAST TRANSMITTER

Illustration 4–5 Metering Board

U406A, U406B, and U407A, with their respective diodes, are diode linearity correction circuits. Their DC inputs come from diode detectors in the RF reflectometer in the RF low-pass filter compartment.

U407B, U407C, Q405, and Q406 are components of a DC squaring circuit. Since the DC output voltage of U407C is proportional to RF voltage squared, it is also proportional to RF power.

U404C, U404A, U403A, and U404D are level sensors for RF power, reflected RF power, PA temperature, and external PA current, respectively. When either of these parameters exceeds the limits, the output of U404B will be forced low, reducing the ALC (RF level control) voltage, which, in turn, reduces the PA supply voltage.

4–8 FM500 User's Manual The DC voltage setpoint for U404A (reflected RF voltage) is one-fifth that of U404C (forward RF voltage). This ratio corresponds to an SWR of 1.5:1 [(1+.2)/(1–.2)=1.5]. The U405 inverters drive the front panel fault indicators.

To get a direct reading of SWR, the reference input of the digital panel meter is fed from a voltage proportional to the forward-minus-reflected RF voltage, while forward-plus-reflected is fed to the digital panel meter input. The panel meter provides the divide function.

U408 & U409 function as data selectors for digital panel meter input and reference voltages. Binary select data for U408 & U409 comes from the display board.

The output voltage of U403D goes positive when the temperature exceeds about 35 degrees C (set by R426) providing proportional fan control.

When the Carrier switch is off or the RF power is less than about 5 watts, the SWR automatically switches to a calibrate-check mode. U406C provides a voltage that simulates forward power, while Q403 shunts any residual DC from the reflected- power source. The result is a simulation of a 1.0 to 1 SWR. (See section 5.4.) 4.6 Motherboard The motherboard is the large board in the upper chassis interconnecting the audio processor, stereo generator, RF exciter, and metering boards. The motherboard eliminates the need for a wiring harness, and provides input/output filtering, test points, and modular customization.

Motherboard components are passive with the exception of the fan driver transistor, power FET Q501.

With Normal-Bypass slide switch SW501, it is possible to bypass the audio processor, connecting the left and right audio inputs directly to the inputs of the stereo generator. CAUTION In the BYPASS position, the pre-emphasis circuits and the filters that protect the pilot and stereo subcarrier are bypassed. As a result, the occupied bandwidth specifications of the transmitter could be compromised. The 15–Hz high-pass filters are also bypassed which may mean that modulation with frequencies below 10 Hz could cause the frequency synthesizer to unlock.

If the audio source is already processed, and further processing is not desired, use the Normal mode instead of Bypass and turn the Processing control on the front panel to “0”.

If it is necessary to provide resistive terminations at the audio inputs (either line- to-line or line-to-ground), you may place resistors directly into the 8–pin DIP socket, A501, located between the XLR input connectors. See Illustration 6–9 and accompanying schematic for the socket pin-out.

Principles of Operation 4–9 sto mond n que o, scrive do con in e, uno si dice ma esto mond ors iamo ch qu o, f dic e in e, uno si dice se rivendo c ors a sc on f m uesto mondo o n q uno si d , diciam che i se, ice e end for iciamo che s scriv o con e d ma amo ch s scrivendo co dici e a n se rivendo m a sc con en m scriv do con ma esto mond qu no s o, in se, u i dice for iciamo che e d en s scriv do con ma 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 display circuit board. To access the component side of the board, remove the front panel by removing 12 screws. The board contains circuits for the digital panel meter, modulation peak detector, and LED display drivers, as well as indicators and switches mentioned above.

Illustration 6–10 and accompanying schematic complement this discussion.

Left and right audio from input stages of the audio processor board (just after the Input Gain attenuator) go to the L VU and R VU input on the display board. Peak rectifiers U601A and U601B drive the left and right Audio Input displays. The LED driver gives a 3 dB per step display. The lowest step of the display driver is not used; rather a red LOW indicator lights when audio is below the level of the second step. Transistors Q601 and Q602 divert current from the LOW LEDs when any other LED of the display is lit.

Resolution of the linear displays, High Band, Wide Band, and Modulation, has been improved using dither enhancement. With dither, the brightness of the LED is controlled by proximity of the input voltage relative to its voltage threshold. The effect is a smooth transition from step to step as input voltage is changed. U606A, U606B, and associated components comprise the dither generator. Dither output is a triangular wave.

Composite stereo (or mono) is full-wave detected by diodes D605 and D606. U607, U613, Q603, and Q604 are components of a peak sample-and-hold circuit.

Oscillator, U609F, supplies a low-frequency square wave to the Fault indicators, causing them to flash on and off.

Digital multimeter inputs are selected with push buttons located to the right of the multimeter menu. Signals from the push buttons are conditioned by U609A and U609B. U610 is an up/down counter. Binary input to U611 from U610 selects a green menu indicator light, and lights the appropriate decimal point on the numeric readout. The binary lines also go to analog data selectors on the ALC/ metering board.

Processing control, R650, is part of the audio processor. (See section 4.2.)

The DPM IN and DPM REF lines are analog and reference voltage inputs to digital multimeter IC U612. They originate from analog data selectors on the ALC/ metering board.

4–10 FM500 User's Manual 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. It has switch-mode voltage regulators to provide +12, –12, and 24 volts. It also contains the program detection and automatic carrier control circuits.

Illustration 6–11 and accompanying schematic complement this discussion.

U703E and U703F convert a 38 kHz sine wave from the stereo generator into a synchronization pulse. In the transmitter, synchronization is not used, thus D709 is omitted.

U704 and U705 form a 24 volt switching regulator running at about 35 kHz. U704 is used as a pulse-width modulator; U705 is a high-side driver for MOSFET switch Q701. Supply voltage for the two IC’s (approximately 15.5 volts) comes from linear regulator DZ702/Q705. Bootstrap voltage, provided by D710 and C714, allows the gate voltage of Q701 to swing about 15 volts above the source when Q701 is turned on. Current through the FET is sensed by R738 and R738A. If the voltage between pin 5 and 6 of U705 exceeds 0.23 volts on a current fault, drive to Q701 is turned off. Turn-off happens cycle by cycle. The speed of the turn-off is set by C713.

U706 is a switching regulator for both +12 volts and –12 volts. It runs at about 52 kHz. Energy for –12 volts is taken from inductor L702 during the off portion of the switching cycle. The –12 volts tracks the +12 volts within a few tenths of a volt. There will be no –12 volts until current is drawn from the +12 volts.

Q702, Q703, and Q704 form an active filter and switch, supplying DC voltage to the RF driver, when the Carrier switch is on.

The program detection circuit is made up of U701 and U702. U701A and U701D and associated circuitry discriminate between normal program material and white noise (such as might be present from a studio-transmitter link during program failure) or silence. U701A and surrounding components form a band-pass filter with a Q of 3 tuned to about 5 kHz. U701D is a first-order low-pass filter. Red and green LEDs on the board indicate the presence or absence of program determined by the balance of the detected signals from the two filters. U702 and U701C form a count-down timer. The time between a program fault and shutdown is selected by jumpering pins on header JP701. For times, see section 5.7. The times are proportional to the value of R721 (that is, times can be doubled by doubling the value of R721).

Principles of Operation 4–11 sto mond n que o, scrive do con in e, uno si dice ma esto mond ors iamo ch qu o, f dic e in e, uno si dice se rivendo c ors a sc on f m uesto mondo o n q uno si d , diciam che i se, ice e end for iciamo che s scriv o con e d ma amo ch s scrivendo co dici e a n se rivendo m a sc con en m scriv do con ma esto mond qu no s o, in se, u i dice for iciamo che e d en s scriv do con ma 4.9 Power Regulator Circuit Boards

The power regulator boards are the two boards mounted under the chassis on either side of a pair of 15,000 µf filter capacitors toward the front of the unit. Each board has the switch-mode voltage regulator for a RF power amplifier, and circuitry for PA supply current metering.

Illustration 6–12 and accompanying schematic complement this discussion.

Diode D804, in series with the battery input, together with the AC-supply diode bridge, provides diode OR-ing of the AC and DC supplies.

U801 and U802 form a switching regulator running at about 35 kHz. U801 is used as a pulse-width modulator; U802 is a high-side driver for MOSFET switch Q801. Power for the two IC’s comes from the 24 volt supply voltage for the RF driver (available when the Carrier switch is on). The voltage is controlled at 16 volts by zener diode DZ801. Bootstrap voltage provided by D802 and C809 allows the gate voltage of Q801 to swing about 16 volts above the source when Q801 is turned on. Current through the FET is sensed by R812 and R812A. If the voltage from pin 5 to 6 of U802 exceeds 0.23 volts on a current fault, drive to Q801 is turned off. This happens on a cycle-by-cycle basis. The speed of the turnoff is set by C805.

In the transmitter, synchronization is not used, thus D801 is omitted.

U803 and Q802 are used in a circuit to convert the current that flows through metering shunt, R819, into a current source at the collector of Q803. Forty millivolts is developed across R819 for each amp of supply current (.04 ohms x 1 amp). Q803 is biased by U803 to produce the same voltage across R816. The collector current of Q803 is the same (minus base current) as that flowing through R822 resulting in 40 microamperes per amp of shunt current. R405 on the metering board converts Q803 collector current to 0.1 volt per amp of shunt current (.04 ma X 2.49 k). (See section 5.4.)

4.10 RF Driver

The RF Driver module is mounted next to the heat sinks on the bottom of the RF Amplifier/Combiner sub chassis. The driver amplifies the approximate 20 milliwatts from the frequency synthesizer to about 15 watts to drive the RF power amplifiers. A CA2832 hybrid, high-gain, wideband amplifier, operating at about 20 volts, provides about one watt of drive to a single MRF137 MOSFET amplifier. The MRF137 stage operates from a supply voltage of approximately 15 to 16 volts.

The circuit board has components for input and output coupling and for power supply filtering.

4–12 FM500 User's Manual 4.11 RF Amplifier

The two RF power amplifier modules are mounted on a combiner board, heat sink, slide rail assembly which slides into the main chassis at the rear, and is fastened to the back panel with six screws. RF power, DC power, and control voltages enter the PA assembly through a 72–pin edge connector that it slides into at the front of the chassis.

The amplifier is built around two Phillips BLF278, dual-power MOSFETs rated for 50 volts DC and a maximum power of about 300 watts. When biased for class B, the transistor has a power gain of 20 dB. (It is biased below class B in the transmitter.)

Input transformer, T1111, is made up of two printed circuit boards. The four-turn primary board is separated from the one-turn secondary by a thin dielectric film. R1112–R1117 are for damping. Trim pot R1111 sets the bias.

Output transformer, T1121, has a one-turn primary on top of the circuit board and a two-turn secondary underneath. Inductors L1121 and L1122 provide power line filtering.

The amplifiers are surrounded by a 50 Ω impedance, input/output combiner board which takes the 15 watts input and divides it equally to each power amp. Then the output from each amplifier is combined to form a single output.

4.12 Chassis

The AC power supply components, as well as the bridge rectifier and main filter capacitor are mounted on the chassis. Changing the jumpers on the AC distribution board (located beside the transformer assembly on the bottom of the transmitter), configures the power transformer for 100, 120, 220, or 240 VAC; see section 2.2 for switching and fuse information. The board also includes MOV voltage-surge suppressors and in-rush current limiters as well as a 12 volt power supply for the PA assembly cooling fans.

The main energy-storage/filter capacitors are located between the two power regulator boards. The DC voltage across each capacitor will be 65 to 70 volts when the carrier is on.

WARNING

Shock hazard!

Do not attempt to short the capacitor terminals. A bleeder resistor will discharge the capacitor in approximately one minute after shutdown.

Principles of Operation 4–13 sto mond n que o, scrive do con in e, uno si dice ma esto mond ors iamo ch qu o, f dic e in e, uno si dice se rivendo c ors a sc on f m uesto mondo o n q uno si d , diciam che i se, ice e end for iciamo che s scriv o con e d ma amo ch s scrivendo co dici e a n se rivendo m a sc con en m scriv do con ma esto mond qu no s o, in se, u i dice for iciamo che e d en s scriv do con ma 4.13 RF Output Filter & Reflectometer

The RF low-pass filter/reflectometer are located beside the motherboard in the right-hand compartment on the top of the chassis. See Illustration 6–14 and accompanying schematic for more information.

A 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 82 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 motherboard, then to the metering board, where they are processed for power control, metering, and for SWR metering and protection.

4.15 Receiver Circuit Board Option

This option allows the transmitter to be used as a translator. The receiver board receives terrestrially fed RF signal and converts it to composite audio which is then fed into the exciter board. Microprocessor controlled phase lock loop technology ensures the received frequency will not drift, and multiple IF stages ensure high adjacent channel rejection. Refer to illustrations 4–6, 6–16 and its schematic for the following discussion.

The square shaped metal can located on the left side of the receiver board is the tuner module. The incoming RF signal enters through the BNC connector (top left corner) and is tuned through the tuner module. Input attenuation is possible with jumper J1 on the top left corner of the receiver board. Very strong signals can be attenuated 20 dB automatically by placing the jumper on the left two pins (“LO” position). An additional 20 dB attenuation is also available with the jumpers in the top left corner of the board. The frequencies are tuned by setting switches SW1 and SW2 (upper right corner). These two switches are read upon power up by the microprocessor (U4). The microprocessor then tunes the synthesizer IC SA1057 (U3) to the selected frequency. The switches frequency range is 87.9 Mhz at setting “00” to 107.9 Mhz at setting “64”. Other custom ranges are available.

The synthesizer chip works on a phase lock loop system. It receives the frequency information from pin 6 of the tuner module, then goes through a FET buffer amplifier (Q2) on its way to synthesizer IC (U3). The synthesizer feeds back a DC voltage through two resistors to pin 4 of the tuner module. Different frequencies cause different tuning voltages to go to the tuner module to tune it on frequency. The frequency synthesizer locks on to the exact frequency needed and adjusts the DC voltage accordingly. The microprocessor tunes the frequencies of the synthesizer IC, but the DC tuning voltage is somewhat dependent on the tuner module.

4–14 FM500 User's Manual Receiver Module RF IN (option)

Stereo Generator

® FM500 FM BROADCAST TRANSMITTER

Illustration 4–6 Receiver Board (optional)

Generally, the voltage is around 0.5 volt DC for tuning 88.1 MHz, and from 5.5 to 6.5 volts DC for tuning 107.9 MHz. The 10.7 MHz IF frequency comes out of the tuner module on pin 5 and is coupled into the first filter FL1; passes through FL1 and into the IF decoder system of IC LM1865 (U1). The FL1 filter sets the bandwidth or everything outside of the bandwidth depending on the filter that is selected. It could be a bandwidth of 180 kHz where everything outside of that is filtered out depending on the filter characteristics. A second filter (F3) is available when the signal has a great amount of interference from an adjacent signal. In such a case, remove the jumper cap that is in the F3 position, then remove the ceramic filter that is in the F4 storage position and place it into the F3 position.

Then the signal goes to a buffer gain stage at pin 1 of LM1865 (U1). From there the signal passes through F2, which is a second filter for further removal of unwanted products, and then it goes on to the IF of that chip. The quadrature coil L4 is tuned to 10.7 MHz as per calibration procedures. This results in a low distortion of around 0.2 to 0.3% on the audio. The audio, still a composite at this point, will come out of pin 15 of that IC (U1) and go to the first buffer U9. Then it goes through a compensation network R54 and C26, and on to the stereo decoder chip at pin 2 of U5.

When a stereo signal is present, Led 1 illuminates which indicates that left and right audio is available. Then the stereo signals go to gain stages U6A and U6B and out to the RCA jacks on the back of the cabinet. These can be used for off-air monitoring of the audio signal. Incoming frequency can be monitored from the frequency monitor BNC jack on the back. The stereo buffer U9, stereo decoder U5, and gain stages U6A and U6B have no effect on the signal that goes through the transmitter. This section along with the composite signal coming out of pin 15 of LM1865 (U1) is totally separate from the transmitter section.

Principles of Operation 4–15 sto mond n que o, scrive do con in e, uno si dice ma esto mond ors iamo ch qu o, f dic e in e, uno si dice se rivendo c ors a sc on f m uesto mondo o n q uno si d , diciam che i se, ice e end for iciamo che s scriv o con e d ma amo ch s scrivendo co dici e a n se rivendo m a sc con en m scriv do con ma esto mond qu no s o, in se, u i dice for iciamo che e d en s scriv do con ma A muting circuit, consisting of C22, a 1N914 diode, R14, and varible resistor R15 mutes the output when a signal is too weak to be understood. The strength of the signal muted is determined by the adjustment of R15. Any signal below the setting of R15 is shorted to +VCC through C22 by the current drawn through R14 and the diode. The audio signal above this setting goes through C17 to the connector P3.

The P3 connector block allows jumpering to either internal circuitry or to external signal processing such as advertisement injection or other forms of altering the signal. If the jumper is installed for internal circuitry, the signal will go through R39 to the input of U2A. This is a buffer that drives the R20 pot located on the top left hand corner of the board. R20 sets signal gain for 100% modulation if adjusted correctly with a full incoming 75 kHz deviation signal. Then the signal goes through R21, R22, and C20 which, along with adjustable pot R24 and C21, forms a compensation network with some phase shifting. This allows the best stereo separation possible by adjusting and compensating for differences in FM exciter boards. The signal is buffered through U2B and finally reaches the output connectors P1 and P2, and on to the transmit circuitry.

The power supply is fairly straight forward. The incoming 12 volt supply goes to a 7809, 9 volt regulator (VR1) which supplies all 9–volt needs on the board. The 9 volts also supplies a 7805, 5 volt regulator (VR2) which supplies all 5–volt needs on the board. Plus and minus 12 volts from the motherboard is filtered and supplies various needs on the board. Finally there is a precision reference voltage supplied through R50 by U7 and U8. These two 2.5 volt reference shunts act very much like a very accurate zenor diode to provide precision 5 volts to the metering board.

4–16 FM500 User's Manual Section 5—Adjustments and Tests

This section describes procedures for (1) advanced users who may be interested in customizing or optimizing the performance of the transmitter and (2) service personnel who want to return the transmitter to operational status following a maintenance procedure.

Adjustments and Tests 5–1 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 appropriate pins of header JP1 on the audio processor board. (See section 2.9.) If you change the pre-emphasis, change the de-emphasis jumpers, JP203 and JP204 on the Stereo Generator board, to match. (See section 2.8.)

5.1.2 Pre-Emphasis Fine Adjustment

Trim potentiometers, R29 and R65, (for left and right channels, respectively) provide for fine adjustment of the pre-emphasis. Set the potentiometers to bring the de-emphasized gain at 10 kHz equal to that of 400 Hz. (At the proper setting, 15.0 kHz will be down about 0.7 dB.)

When making these adjustments, it is important that you keep signal levels below the processor gain-control threshold.

A preferred method is to use a precision de-emphasis network in front of the audio input. Then, use the non-de-emphasized (flat) output from the FM modulation monitor for measurements.

5–2 FM500 User's Manual 5.2 Stereo Generator Adjustments

5.2.1 Separation

Feed a 400 Hz sine wave into one channel for at least 70% modulation. Observe the classic single-channel composite stereo waveform at TP1 on the RF Exciter circuit board. Adjust the Separation control for a straight centerline.

Since proper adjustment of this control coincides with best stereo separation, use an FM monitor to make or confirm the adjustment.

5.2.2 Composite Output

Adjust the composite output with a modultion monitor following the steps below: 1. Set the Stereo-Mono switch to Mono. 2. Check that the setting of the Modulation compensation control, R17 on the RF Exciter circuit board, falls within the range specified for the frequency of operation. (See section 2.3.1.) 3. Feed a sine wave signal of about 2.5 kHz into the left channel at a level sufficient to put the wideband gain-reduction indicator somewhere in the middle of its range. 4. Set the Composite level control to produce 90% modulation as indicated on an FM monitor. 5. Apply pink noise or program material to the audio inputs and confirm, on both Mono and Stereo, that modulation peaks are between 95% and 100%.

5.2.3 19 kHz Level

Adjust the 19 kHz pilot for 9% modulation as indicated on an FM modulation monitor. (The composite output should be set first, since it follows the 19 kHz Level control.)

5.2.4 19 kHz Phase

1. Apply a 400 Hz audio signal to the left channel for at least 70% modulation. 2. Look at the composite stereo signal at TP301 on the RF Exciter circuit board with an oscilloscope, expanding the display to view the 19 kHz component on the horizontal centerline. 3. Switch the audio to the right-channel input. When the 19 kHz Phase is properly adjusted, the amplitude of the 19 kHz will remain constant when switching between left and right. 4. Recheck the separation adjustment as described in section 5.2.1.

Adjustments and Tests 5–3 5.3 Frequency Synthesizer Adjustments

5.3.1 Frequency (Channel) Selection

Refer to section 2.3.

5.3.2 Modulation Compensator

Refer to section 2.3.

5.3.3 Frequency Measurement and Adjustment

Next to the 10.24–MHz crystal on the RF Exciter board is a 1–11 pF piston trimmer capacitor (C3). Use C3 to set the frequency of the 10.24–MHz crystal while observing the output frequency of the synthesizer.

Use one of these methods for checking frequency: ❑ Use an FM frequency monitor. ❑ Couple a frequency counter of known accuracy to the output of the synthesizer and observe the operating frequency. (Do not connect to the 10.24–MHz clock circuit.)

5.3.4 FSK Balance Control

An FSK signal (used for automatic identification of FM repeaters) shifts the frequencies of the 10.24–MHz crystal reference oscillator and the VCO.

Use an oscilloscope to observe the cathode end of D4. With no program, the pulse will be less than 1 µsec wide. With an FSK input (a 20–Hz square wave at the FSK input will work), set trim pot R45 for minimum pulse width.

The setting will vary slightly with operating frequency.

5–4 FM500 User's Manual 5.4 Metering Board Adjustments

5.4.1 Power Calibrate

While looking at RF Power on the digital panel meter, set the Power Calibrate trim potentiometer to agree with an external RF power meter.

5.4.2 Power Set

With the front panel RF Output control fully clockwise, adjust the Power Set trim pot to 10% more than the rated power (33 W for FM30, 110 W for FM100, 275 W for FM250, 550 W for FM500) as indicated on an accurate external watt meter. If the authorized power is less than the maximum watts, you may use the Power Set to limit the range of the RF Output control. Operation below 100 watts is not recommended as instability can occur which could damage the transmitter. CAUTION

Possible equipment damage!

Operation below 100 watts can cause oscillations and other problems that could damage the transmitter.

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 calibrate-check mode. (See section 4.5 for more information.)

Set the digital panel meter to read SWR. With the Carrier switch off, set the SWR CAL trim pot to read 1.03.

5.4.4 PA Current Limit

Since it may not be practical to increase the PA current to set the PA Current Limit control, you may use this indirect method.

With the carrier turned off, look at the DC voltage at the right end of R413 on the Metering board. The current limit, in amperes, will be 0.35 amps higher than ten times this voltage. Set the current limit for 16.5 amps or 1.615 volts at R413.

Adjustments and Tests 5–5 5.5 Motherboard Adjustments

For Normal-Bypass switch setting, see section 2.10.

5.6 Display Modulation Calibration

The Modulation Calibrate trim pot sets the sensitivity of the front panel Modulation bar graph display.

This adjustment may be made only after the Output trim pot on the Stereo Generator board has been set. (See section 5.2.4.) 1. Set the Stereo-Mono switch to Mono. 2. Feed a sine wave source of about 2.5 kHz into the left channel at a level sufficient to put the wideband gain-reduction indicator somewhere in the middle of its range. 3. Set the Modulation Calibrate trim pot so that the “90” light on the front panel Modulation display just begins to light.

5.7 Voltage Regulator Adjustments

JP701, a 10–pin header on the Voltage Regulator board, sets the time between program failure and carrier turnoff. Pins 1 and 2 are the two pins closest to the edge of the board. The times are approximate. Sections 2.11, 2.12, and 4.8 contain further information. 1. Short pins 1 and 2 for a 30–second delay. 2. Short pins 3 and 4 for a 2–minute delay. 3. Short pins 5 and 6 for a 4–minute delay. 4. Short pins 7 and 8 for an 8–minute delay. You may select other times by changing the value of R721. The time is proportional to the resistance.

5.8 Bias Set (RF Power Amplifier)

The Bias Set trim pot is located on the PA module on the input circuit board. Set the trim pot to its midpoint for near-optimum bias.

5–6 FM500 User's Manual 5.9 Performance Verification

Measure the following parameters to receive a comprehensive characterization of transmitter performance: ❑ Carrier frequency ❑ RF output power ❑ RF bandwidth and RF harmonics (see section 5.12) ❑ Pilot frequency, phase, and modulation percentage ❑ Audio frequency response ❑ Audio distortion ❑ Modulation percentage ❑ FM and AM noise ❑ Stereo separation between left and right ❑ Crosstalk between main channel and subcarrier ❑ 38–kHz subcarrier suppression In addition to the above tests, which pertain to signal quality, a complete check of the unit will include items listed in section 5.21.

5.9.1 Audio Proof-of-Performance Measurements

References to “100%” modulation assume 9% pilot and 91% for the remainder of the composite stereo signal.

Because the audio processing threshold is at 90% modulation, it is not possible to make audio proof-of-performance measurements at 100% modulation through the audio processor. Instead, audio data for 100% modulation is taken from the input of the stereo generator (SW501 on Motherboard set for Bypass). Then, data, including the audio processor (SW501 set for Normal), is taken at a level below the audio processing threshold.

5.9.2 De-emphasis Input Network

A precision de-emphasis network, connected between the test oscillator and the audio input of the transmitter, can be very helpful when making the audio measurements. Note that the input impedance of the transmitter or the source impedance of the test oscillator can affect network accuracy. With the de-emphasis network, oscillator level adjustments need only accommodate gain errors, instead of the whole pre-emphasis curve.

Adjustments and Tests 5–7 5.10 Carrier Frequency

Carrier frequency is measured at the output frequency with a frequency monitor or suitable frequency counter.

To adjust frequency, see section 5.3.3. (FCC tolerance +/– 2000 Hz per FCC Part 73.1540 and 73.1545.)

5.11 Output Power

The output power reading on the front panel display should be 90–105% of the actual value. For a more precise measurement, use a watt meter in the RF output line. See sections 5.4.1 and 5.4.2 for setting power.

5.12 RF Bandwidth and RF Harmonics

You can observe RF bandwidth and spurious emissions with an RF spectrum analyzer.

In the Stereo mode, feed a 15.0 kHz audio signal into one channel to provide 85% modulation as indicated on a monitor. Doing so produces 38% main, 38% stereo subcarrier, and 9% pilot per FCC Part 2.989. As an alternative, use pink noise into one channel.

Using a spectrum analyzer, verify the following (per FCC 73.317): 1. Emissions more than 600 kHz from the carrier are at least 43 + 10log(power, in watts) dB down (70 dB for 500 watts). The scan should include the tenth harmonic. 2. Emissions between 240 kHz and 600 kHz from the carrier are down at least 35 dB. 3. Emissions between 120 kHz and 240 kHz from the carrier are down at least 25 dB.

5.13 Pilot Frequency

The pilot frequency should be within 2 Hz of 19 kHz. (FCC Part 73.322.) Using a frequency counter, measure 1.9 MHz at pin 1 of U209 on the Stereo Generator board. A 200-Hz error here corresponds to a 2-Hz error at 19 kHz. If the frequency is off by more than 50 Hz, you may change the value of C213. (Changing C213 from 56 pF to 68 pF lowers the 1.9 MHz by about 35 Hz.)

5–8 FM500 User's Manual 5.14 Audio Frequency Response

For the response tests, take the readings from an FM modulation monitor.

Make audio frequency response measurements for left and right channels at frequencies of 50 Hz, 100 Hz, 400 Hz, 1 kHz, 5 kHz, 10 kHz, and 15 kHz. See sections 5.9.1 and 5.9.2.

5.15 Audio Distortion

Make distortion measurements from the de-emphasized output of an FM modulation monitor.

Make audio distortion measurements for left and right channels at frequencies of 50 Hz, 100 Hz, 400 Hz, 1 kHz, 5 kHz, 10 kHz, and 15 kHz. See sections 5.9.1 and 5.9.2.

5.16 Modulation Percentage

While feeding an audio signal into the left channel only, confirm that the total modulation percentage remains constant when switching between Mono and Stereo.

Measure modulation percentage with an FM modulation monitor, or by using an HF receiver and Bessel nulls. See section 5.2.2.

19–kHz pilot modulation should be 9%.

5.17 FM and AM Noise

Take noise readings from a de-emphasized output of a modulation monitor.

5.18 Stereo Separation

Make left-into-right and right-into-left stereo separation measurements with an FM modulation monitor for frequencies of 50 Hz, 100 Hz, 400 Hz, 1 kHz, 5 kHz, 10 kHz, and 15 kHz.

5.19 Crosstalk

For stereo crosstalk measurements, both left and right channels are fed at the same time. For best results, there needs to be a means of correcting small imbalances in levels and phase. The balance is made at 400 Hz.

Adjustments and Tests 5–9 5.19.1 Main Channel Into Sub

Feed the left and right channels in phase with audio (L+R) at 50 Hz, 100 Hz, 400 Hz, 1 kHz, 5 kHz, 10 kHz, and 15 kHz at 100% modulation, while observing the stereo subcarrier (L-R) level on an FM modulation monitor.

5.19.2 Sub Channel Into Main

Feed the audio into the left and right channel as above, with the exception of reversing the polarity of the audio of one channel (L-R input). Using the frequencies of 5.19.1 above, observe the main channel (L+R) level with a modulation monitor.

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, should be down at least 40 dB.

5.21 Additional Checks

In addition to the tests and adjustments mentioned in this section, the following checks ensure a complete performance appraisal of the transmitter: 1. Perform a physical inspection, looking for visible damage and checking that the chassis hardware and circuit boards are secure. 2. Check the functionality of switches and processing control. 3. Verify that all indicators function. 4. Check the frequency synthesizer lock at 80 MHz and 110 MHz. 5. Measure the AC line current with and without the carrier on. 6. Perform a functional test of the SCA input, Monitor outputs, and the monitor and control function at the 15–pin, D-sub connector. 7. Test the functionality of the FSK circuit. 8. Check the operation and timing of the automatic carrier-off circuitry associated with program failure. 9. Check all metering functions. 10. Test ALC action with PA current overload, SWR, and PLL lock.

NOTE: FCC type acceptance procedures call for testing the carrier frequency over the temperature range of 0–50 degrees centigrade, and at line voltages from 85% to 115% of rating. (See FCC Part 2.995.)

5–10 FM500 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 transmitter.

Reference Drawings 6–1 6.1 Views

Gain Reduction/Expansion Modulation Indicators Digital Multimeter Multimeter Select Indicators Carrier Switch

® FM500 FM BROADCAST TRANSMITTER

Audio Processor Processing Control Fault Indicators Power Switch Input Level Indicators Input Gain Stereo/Mono Switch Relative RF Switches Voltage Out

Illustration 6–1 Front View

RF Output Ground Composite Audio Monitors Audio Inputs RF Output Monitor Input

SCA IN COMPOSITE IN MONITOR RIGHT LEFT/MONO

R L

REMOTE I/O

1 23

FUSE

AC Power In Power Amplifier SCA Inputs Remote I/O and Cooling

Illustration 6–2 Rear View

6–2 FM500 User's Manual RF Exciter Stereo Generator Low-pass Filter

Metering Audio Processor

® FM500 FM BROADCAST TRANSMITTER

Illustration 6–3 Chassis Top View

Power Amp Power Transformer Fans

Power Voltage Regulator Distribution Board Board

Power Regulator Boards Filter Capacitors

front of transmitter

Illustration 6–4 Chassis Bottom View

Reference Drawings 6–3 6.2 Board Layouts and Schematics

Illustration 6–5 Audio Processor Board

6–4 FM500 User's Manual R9 1K L VU GAIN REDUCTION VOLTS P-P R4 THRESHOLD 1.1 C3 R6 24.9K 10DB 3.5 R2 1.0 24.9K GAIN: U5, Pin 2 to U8, Pin 2 1K 1 1 R8 U1B R20 20DB 11 (No Hi-band gain reduction) L IN1 C5 +12V +5V 30.1K TL072 .047 75K FLAT A=0 1 6 1 C1 +12V L LP2 AD632 R23 25uSEC A=0.33 7 14 50uSEC A=0.67 100PF 100K 1 C12 8 5 L LP1 U4B 7 1 75uSEC A=1.0 D3 R5 R34 0.1 R38 2 TL072 9 (+/-5.0V PK) R3 24.9K 24.9K 1 1K 1 6 2 L OUT 1 U5 L IN2 1K 3 7 13 U1A R1 5 12 10 R31 100 24.9K R35 4 TL072 D2 +12V C11 C4 R7 R22 R26 1 240K D4 1 31 220PF 1.0 24.9K R13 C6 11.3K R24 C2 -12V 100K 1 2.0K .047 1 24.9K AD632 100PF R17 14 C10 1 1 7 .0027 360K -12V PRE-EMP. 1 R39 -5V D1 9 POLY R28 1K R37 Q1 6 R36 R14 C8 U8 2 24.9K 2N5087 OPEN R29 13 24.9K 1.0K 1.0 7 10K 12 10 5 R12 1 POLY R25 20K 1 24.9K 1 31 U12B 1 R32 U10B 6 TL072 R15 R30 TL072 12K 7 499 49.9K 6 -12V 5 U3 1 R56 1 7 75K R33 13 12 5 X X0 1 14 U7B 10K D6 X1 D5 3 15 TL072 Y X2 R16 11 +12V X3 499 +5V 1 U4A 16 1 8 +12V +5V +5V Y0 TL072 5 C17 C18 2 Y1 7 2 .047 .047 1 -5V Y2 R59 D9 4 R LP2 3 14 AD632 R10 R11 Y3 100K 1 8 6 7 1 C24 INH R67 R70 R74 47K 47K 10 R LP1 4 9 (+/-5.0V PK) 0.1 A 24.9K 24.9K 1K 9 2 R OUT B U6 -12V 13 R46 12 10 C23 74HC4052 D8 /+12DB 360K +12V 220PF R71 R98 R58 R62 /+6DB 1 31 240K 100 11.3K R60 100K D10 R49 1 24.9K 14 AD632 C22 R64 +12V 7 .0027 R48 -12V OPEN 1 R81 -5V R VU 20K 1 R50 D7 9 POLY 1K 8 R72 R73 2.0K C20 PRE-EMP. 2 2 U9 24.9K 24.9K 1K 1 1.0 13 1 R61 R65 C15 12 10 3 R40 R42 R44 POLY 24.9K 1.0 10K U10A +12V 1K 24.9K 24.9K R51 Q2 R IN1 1 31 4 TL072 1.0K 2N5087 R68 U12A 1 +12V 12K 8 +12V -12V 2 TL072 C13 R123 R66 8 -12V 1 100PF R47 49.9K 8 50K 2 3 30.1K R52 1 R69 C16 2 1 R41 R43 1 499 U7A 1.0 1 6 3 10K 4 1K 24.9K 1 R90 R IN2 3 7 TL072 1K U2A 5 4 -12V 4 TL072 U2B C14 TL072 R53 -12V C29 D11 D12 R45 499 100PF -12V C50 R87 0.1 C49 24.9K 1 1 47PF 3.3K 47PF 2 3 -5V +5V C27 HEAVY SW1A .047 R85 R119 3.3K PROC A 4.7K R83 R88 R109 10M 3.3K 10K PROC B R650 C33 -5VDC at 0DB GR 100K R103 +12V 4.1V at 20 DB GR R94 .047 R89 3.3K D19 PROC C 20.0K C36 330K .01 1 +5.00V LIGHT 8 +5V R86 2 VDD POT LOCATED C34 3.3M JP1 R104 1 +5V ON DISPLAY PCB R95 OPEN +5V C28 HEADER 4X2 OPEN 2 6 3 20.0K R97 IN VO R120 1.0 1 49.9K 100 POLY FLAT 1 2 U17 4 U18A C38 C46 C47 SW1B 4 1 25uS 3 4 TL072 1.0 0.1 0.1 5 C32 50uS 5 6 -12V R78 R79 6 100PF REF02 75uS 7 8 91K 49.9K R96 4 5 R118 1 20.0K R105 GND TRM 10.0K C26 R121 1 1M 100PF 1 10.0K 1 +12V VEE Q5 Q7 LM394 LM394 R101 8 8 1 1 8 D16 2 8 C1 1 C8 10K R106 R107 7 2 D13 +12V 2 7 3mV/DB 1 C37 7 B2 2 B 7 1K 10K 7 6 3 3mV/DB 3 6 3 .01 6 E3 R91 3 E 6 5 4 8 4 5 U14A R122 VSS 5 4 10M 4 5 6 100 2 R93 TL072 4 7 -5V 1 -5V R92 10K 5 3 -12V U13A R100 C35 U18B TL072 1K 120 C39 C48 4 D17 1.0 TL072 1.0 0.1 D20 D21 -12V R82 R76 D18 C30 120 D15 10K 560 1.0 TEST +12V +12V R80 D14 Q3 R99 .25V/DB 3.3K YEL R77 C44 2N5210 3.3K R75 3.3K C40 C42 0.1 1.0 0.1 2.4K

C8A C20A OPEN OPEN -5V C43 R116 0.1 R112 49.9K C45 49.9K 1 C41 0.1 C31 1.0 C25 R111 1 100PF R115 -12V 100PF 49.9K +12V -12V 1 49.9K J3 +12V 1 8 +12V R117 1 2 8 2 -12V R113 6 100 3 4 6 2 6 1 0.25V / DB HI GR /+6DB 100 J1 J2 5 6 7 6 1 .25V / DB BR GR 7 7 3 /+12DB 7 8 5 7 3 5 5 L IN1 L VU R102 1 2 10 9 9 10 U13B 5 4 L IN2 R OUT R VU R84 49.9K U16A 3 4 8 7 11 12 TL072 4 U15A U14B U16B R IN1 +5.00V 49.9K 1 TL072 5 6 6 5 13 14 TL072 TL072 TL072 -12V R IN2 L OUT PROC A U15B 1 7 8 4 3 15 16 -12V R114 PROC B TL072 9 10 2 1 17 18 R110 49.9K L LP1 PROC C 11 12 19 20 49.9K 1 L LP2 RECEPT 5X2 BR GR 13 14 21 22 R LP1 HI GR 1 SCM, FM AUDIO PROCESSOR 15 16 23 24 NOTES : R LP2 TEST 17 18 25 26 19 20 1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% UNLESS OTHERWISE SPECIFIED. 103202 2. ALL CAPACITORS ARE IN MICROFARADS UNLESS OTHERWISE SPECIFIED. RECEPT 10X2 RECEPT 13X2 3. ALL DIODES ARE 1N4148 UNLESS OTHERWISE SPECIFIED. AUDIO PROCESSOR Reference Drawings 6–5 Illustration 6–6 Stereo Generator Board

6–6 FM500 User's Manual +12V R55 24.9K EXT RTN R54 24.9K 1%

C26 1.0 EXTERNAL COMPOSIT IN (3.5V P-P for 75KHz) 8 2 R58 R56 3.9K 1 EXT IN 24.9K 1% 3 U6A 4 TL072 R57 D3 D4 24.9K

C27 C4 -12V 1.0 R5 C5 (3.5V P-P for 7.5KHz) 0 OHM 1K .0027 SCA IN POLY R3 C3 15.2 KHz LOW-PASS FILTER 100PF (8th ORDER ELLIPTICAL) JP1 0 OHM INPUT L 1 3 +12V LTC1064-1 2 1 14 8 R12 R7 LPIN L 2 13 2 U3A 10.0K 3.65K TL072 1% 3 12 1 -6V 1% 3 +6V 4 U1 11 R9 5 R1 10 330 4 +12V 2K 1% 6 9 LPOUT L R6 499 7 8 C6 +6V R38 1% 1030PF 8 R11 C1 -12V R10 2 1M R8 1 100 MON L C28 OUTPUT R15 (SELECTABLE BY TEST, USE .0027 2.49K 1% 4.99K 1% 3 1.0 4.02K 4.12K OR 4.15K IF NEEDED) POLY R14 1K 1% 4 U4A 1 3 U5 JP3 TL072 C9 74HC4053 .0027 2 D5 POLY 50 75 -12V 16 JP2 12 14 X0 X INPUT R 1 3 C7 13 LTC1064-1 .01 POLY X1 15 2 1 14 2 Y LPIN R 6 Y0 R16 2 13 R19 D6 1 4 6 3 7 Y1 Z 100 COMP OUT 12 3.65K 1% 7 4 5 5 5 U2 11 R2 Z0 (•3.85V P-P) 5 3 10 330 U3B Z1 U6B 6 9 LPOUT R R18 TL072 TL072 499 7 8 R39 6 1% C10 R20 R22 R24 INH C2 1M 2.49K 6 11 1030PF 4.99K 7 100 MON R MONO/STEREO A .0027 1% 1% 10 5 9 B POLY C U4B +6V R21 1 3 TL072 8 7 JP4 10K R17 2 100 50 75 C24 D1 C23 D2 R53 1.0 1.0 +5.00V 10K -6V 1N5818 1N5818 C11 C30 .01 POLY /EXT ENABLE 1.0 R13 COMP METER +6V 24.9K 1% R204 1K SYNC OUT R23 74HC86 14 R28 C31 24.9K 1% J3 1 243K 1% 3 1.0 U10A C17 10 9 +6V 2 C15 R33 R37 8 7 0.1 0.1 C37 -12V 10.0K 1% 1K 1.52 MHz +12V OPEN +12V 6 5 4 3 4 U12 2 1 R27 6 B-B 4214 R26 C29 100 5 U10B 14 38 KHz RECEPT 5X2 1K 1.0 R29 7 100K 1% 3.0VP-P 1 R48 R34 9 R25 49.9K 4.3K 1% 2 1M 3.8 MHz 13 C18 R40 J1 U8A 12 10 1 Y1 74HC390 16 .0027 10K U7F 0 9 8 7 6 5 4 3 2 1 POLY 1 EXT IN 7.6MHZ 1 15 14 3 13 11 3 2 EXT RTN 1 2 13 12 4 CK Q 12 CK QA U9B C L V V S S I H B L 5 11 L S D A A 1 N P P P 3 CK Q CK QB 74HC393 14 R46 SEPARATION SCA IN 6 10 K H + + / A V A A A 4 COMP OUT U7A 7 2 QC 7 14 QC 9 13 11 B A 10K 5 CLR QD CLR QD A Q A COMP METER C13 C14 10 6 74HC04 Q U11 -12V MONO/STEREO 56PF C12 33PF 8 9 5 C21 R32 7 NPO NPO U8B QC R47 /EXT ENABLE 5.5—18PF 12 8 0 LMF100 0.1 10K 8 74HC390 304 Khz CLR QD C / A I 20K GND L 1 V V G S N H B L 9 10 INPUT L 7.6 MHz 7 K 0 D A N 1 V P P P INPUT R B 0 - - D B B B B B 11 1 1 1 1 1 1 1 1 1 2 12 U9A 1.9MHz 1 2 3 4 5 6 7 8 9 0 74HC393 RECEPT 12X1 3 1 QA A 4 R36 CLK QB R30 J2 5 74HC86 49.9K 6 QC 2 9 243K 1% CLR 1 MON L QD 8 1% 2 QA 19 KHZ LEVEL MON R 10 U10C 19 KHZ PHASE R43 3 R242 1K R244 10K 33K 4 5 GND QB LPIN L 12 6 R35 R41 LPOUT L 11 C19 7 13 U10D C16 0.1 10.0K 1% 510 LPIN R QC 0.1 8 LPOUT R R31 9 +5.00V 7 100K 19 KHz 10 +5.00V C20 SYNC OUT QA XOR QC 1% 3.3VP-P 11 U7B .0027 NOTES : 12 ______74HC04 POLY C32 3 4 1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% UNLESS OTHERWISE SPECIFIED. QB XOR QC 1.0 RECEPT 12X1 VR1 2. ALL CAPACITORS ARE IN MICROFARADS UNLESSOTHERWISE SPECIFIED. LM317 3. ALL DIODES ARE 1N4148 UNLESS OTHERWISE SPECIFIED. +12V +6V +12V 1 3 -6V U7C IN OUT 74HC04 C Current at U211 pin 4. C33 C34 5 6 1.0UF R49 U205 Connections CROWN INTERNATIONAL, INC. 2 240 1.0UF 1718 WEST MISHAWAKA ROAD ELKHART, IN. 46517 PHONE (219) 294-8000 EXTERNAL COMPOSITE U7D QD 74HC04 9 8 R50 910 SCM, FM STEREO GENERATOR QB XOR QD U5Y U7E X1 QC XOR QD 74HC04 STEREO X DRAWN JFL 7-28-97 APPROVED BY : DO NOT SCALE PRINT 11 X0 10 VR2 LM337 B CHECKED JB 1 ME SUPERSEDES -12V -6V -12V 1 3 IN OUT U5Z Current at U211 pin 17. Z1 SCALE NONE EE E.C. C35 C Z U206, pin6 R51 C36 U5X 1.0 Y1 Z0 2 240 47UF DWG. NO. REV MONO Y PROJ # MLOWCM0 PE Y0 C /EXT EN FILENAME: 103203A.SCM NEXT ASM: 103203 A STEREO/MONO A R52 910

STEREO GENERATOR

Reference Drawings 6–7 SEE NOTE 10

TOP SIDE COMPONENT MAP, FM-VFM EXCITER PWB: 200440-PWB-A.PCB M200440PT-A.DOC

UNCONTROLLED THESE DRAWINGS, SPECIFICATIONS AND ASSOCIATED SIZE DWG. NO. REV UNLESS OTHERWISE MARKED IN RED BY CM AS A ELECTRONIC FILES ARE THE PROPERTY OF INTERNATIONAL CONTROLLED COPY, COPIES OF THESE DOCUMENTS AND RADIO AND ELECTRONICS CORP., AND SHALL NOT BE REPRODUCED, B 200440-PWA A ASSOCIATED ELECTRONIC FILES ARE UNCONTROLLED AND COPIED, OR USED AS THE BASIS FOR THE MANUFACTURE OR SALE OF ARE FOR REFERENCE ONLY. APPARATUS OR DEVICES WITHOUT PERMISSION. SCALE: N/A PROJECT #: 509 SHEET: 1 OF 1 1 2 3 4 5 6 DWG. NO. 200440-SCH REV. A 8 9 10 11 12 REVISION HISTORY APPROVALS E . C . N. REV DESCRIPTION DATE DWN CHK CM PE 1 FOR PROTOTYPE 01-04-02 DW 2 MODIFIED PER MIKE SENEKI 02-06-02 DW 3 CHG'D R18 PER EAD MRH01. R18 WAS 91K OHM. U5 WAS C 6900-5 06-24-02 DW H H 246 A-G 4 R8 WAS 1.0K OHM. 05-23-03 DW 277 A PRODUCTION RELEASE 01-29-04 DW DW DP

+8V 88-108 MHZ

+12V R24 C6 +12V 100PF 150 C44 2 A2 1 8 1 +5V R68 GND R30 MAR-6 C7 10 2 499K +8V DATA .001 VU5 1 5 1% CLOCK /LOCK U7A 3 R25 37 U7B LOAD 6 DL1 680 NE5532 G +5V GREEN G R33 R35 499K C22 4 NE5532 1% +5V 100 .001 C9 1% D11 .001 + C21 1N4148 R38 9 7 5 3 1 R23 10/35V 15 PL1 R22 1M C19 TANT. 200K DL2 C82 HEADER 5X2 LOCK DET. 13 12 11 10 LOCK RED .001 10 8 6 4 2 R26 .01 C8 C10 680 1 U4F U4E .001 VVCO D6 74HC14 74HC14 1N4148 R9 100K C12 R39 1% 1 POLY 100 REMOTE FREQUENCY CONTROL 1% R5 U6 C23 1.0K VDD R7 10 MAR-6 OSC in 1 16 C11 .001 VCO61 .001 1 16 R12 7 5 3 1 1% OSC out 2 15 MC33284P POS-150 1 2 RF OUT 2 15 C4 C13 R11 1.0K A1 3 14 13 R4 100K 1% 3 14 1 3900PF 100K 1% F Fin 4 13 9 14 C26

4 13 1% U5D 8 6 4 2 C24 F 5 12 8 12 .001 5 12 R6 U5C R61 33pF NPO

6 11 10 R66 3 10.24MHZ 6 11 100K C15 7 10 R10 10.0K 7 10 1% MC33284P 0.01 1% 150 FSK-R Y1 8 9 100K C14 8 9 1% .001 POLY MC145170 R67 R8 R16 R62 C1 C3 C62 15 1-10PF 100 100K 100 33PF NPO C2 CLOCK 1% 1% 220pF 1% 39PF NPO /ENABLE +5V +5V D12 + C61 DATA R64 4.99K 1N4148 47/20V 1% TANT. R15 R65 +5V 6 D7 100K 100K U1 9 7 U2 9 7 7 1N4148 1% R63 74HC165 74HC165 U5B 1% HD1 VDD 5 39 R13 +8V JP1 100K + D8 QH QH QH QH 9 7 5 3 1 MC33284P C27 JUMPER E R3 1% 1N4148 E R2 150K 10/35V 10.0K 1 18 C77 RA2 RA1 TANT. C81 1% 2 17 0.1 10 8 6 4 2 SER A B C D E F G H CLK INH SH/LD SER A B C D E F G H CLK INH SH/LD RA3 RA0 3 16 R14 1000pF D2 RTC OSC1 1 2

HEADER 5X2 4 15 100K 1N4148 CLR OSC2 C5 5 14 1% -12V R84 3 4 5 6 2 1 3 4 5 6 2 1

10 11 12 13 14 15 10 11 12 13 14 15 VSS VDD D1 4 6 13 .001 POLY 1N4148 TP RB0 RB7 R80 R81 5.11K 1% LOAD 7 12 R21 RB1 RB6 24.3K 1% 10.0K DATA 8 11 100K 3 RB2 RB5 1% R83 CLK 9 10 1% 1 6 S RB3 RB4 U8A 5.11K 1% 2 U8B 7 RP1 R1 C76 TL072 5 G

U3 R88 100K RPACK 10.0K 0.1 PIC16C61 D5 1N4148 TL072 Q72 D13

1% 30.1K 1% C78 0.1 10 8 IRFD9120 D 3.9V 9 10 8 9 +12V 7 8 C28 1 6 7 8 PB1 POLY 5 6 RESET 4 5 9 R20 1M R89 3 4 26.7K 1% D 2 3 R18 4 VU5 D 1 2 68K C43 R87 1 2 C80 D4 1 10K 0.1 U5A 1 PWR. CNTRL TILT 1N4148 3 RP2 R82 R86 TP2 100K RPACK MC33284P -12V 24.3K 1% 680.0 4.5 - 8.0V 11 C79 0.1 R19 5 4 3 2 1 5 4 3 2 1 5 4 3 2 1 5 4 3 2 1 5 4 3 2 1 25K C29 1 R85 LF SEP. 2K SW1 SW2 SW3 SW4 SW5 D14 + R90 PWR. CNTRL. OFFSET

R17 C30 499 1% TP1 1K BECKMAN 10/35V TANT. 6.2V 1N753A COMPOSITE IN VR3 LM317 C41 +5V +12V 3 1 8.26V IN OUT +8V C 100PF C R27 10.0K 1% C R51 + C36 237 1% + DL3 10/35V 2 C38 U4B U4A R28 10.0K 1% AMBER TANT. 10/35V 74HC14 74HC14 TANT. + C37 R52 4 3 2 1 1.27K +5V R41 10.0K 1% 10/35V 1% R43 TANT. NOTES : 1.0K R47 D9 R42 10.0K 1% 1.0K 1N4148 UNLESS OTHERWISE SPECIFIED: 1% 1% FSK 9 8 5 6 1. ALL RESISTORS ARE IN OHMS, R40 10.0K 1% C31 U4D U4C C33 1/4W, 5% TOL. 74HC14 74HC14 .001 33pF 2. ALL CAPACITORS ARE IN MICROFARADS. FSK-R VR2 C32 LM78L05 REFERENCE DESIGNATORS NOT USED: .001 3 1 J1 IN OUT +5V C16, C17, C18, C20, C25, C34, C45-60, C63-75, Local/Remote Frequency Select C + C40 B 2 4 6 8 R48 C39 B 26 25 10 R44 1 Q1-71, R29, R31, R32, R34, R36, R37, R49, R50, 24 23 1.0K D10 RF OUT C42 HD2 10.0K 10/35V 1% 1N4148 2 R53-60, R69-79, VCO1-VCO60. 22 21 .001 HEADER 5X2 1% TANT.

20 19 1 3 5 7 9 COMPOSITE IN 18 17 16 15 -12V -12V 14 13 FSK BAL. FSK R45 12 11 +12V +12V 10K 10 9 Local/Remote C35 8 7 D3 /LOCK .001 6 5 1N4148 LOCK GND 4 3 FSK-ID-CHAN GND R46 2 1 CH. SEL. 39K RECEPT 13X2 IREC BAND LIMIT APPROVALS INTERNATIONAL RADIO AND ELECTRONICS CORP. DIRECT FSK 25166 LEER DRIVE ELKHART, IN. 46514 AUTO ID DW 01-04-02 ID DWN 574-262-8900 WWW.IREC1.COM CHK DJ 01-05-02 TITLE: CM DW 01-05-02 A SCH, FM-VFM RF EXCITER A UNCONTROLLED THESE DRAWINGS AND SPECIFICATIONS ARE THE PE DP 01-05-02 PROPERTY OF INTERNATIONAL RADIO CORP. SIZE DWG . NO . REV UNLESS OTHERWISE MARKED IN RED INK BY CM AS A AND SHALL NOT BE REPRODUCED, COPIED OR USED AS DISTRIBUTION CONTROLLED COPY, COPIES OF THESE DOCUMENTS 200440-SCH A THE BASIS FOR THE MANUFACTURE OR SALE OF APPARATUS OR C INCLUDING ASSOCIATED ELECTRONIC REPRODUCTIONS K DEVICES WITHOUT PERMISSION. ARE FOR REFERENCE ONLY. FILENAME: SCALE : NONE PROJ NO. 509 SHEET 1OF 1 1 2 3 4 5 6 7 8 9 10 11 12 C_L_SHT1_A.DOT REV. A D 8169-1

Illustration 6–8 RF Metering Board (Add 400 to component designators for schematic reference)

6–10 FM500 User's Manual PAV +12V +5.00V J2-4 C401 R450 R406 8 D406 J401 .01 U2 R409 10K Parts not loaded: 100K 1 2 J4-3 100 +5V 1 REM PADCV R411 U5 10 9 15K 8 7 C403, 404 3 1.00V = 10VDC -12V -12V PAI LIMIT 6 5 DZ401 U402A 9 8 SWR LAMP +12V +12V R402, 403, 404 4 TL072 J3-20 4 3 R414 2 1 Q401, 402 R412 U405D U401 -12V 2.2M 74HC14 10K POT H RECEPT 5X2 LB401 R410 R413 D407 R401 6 J4-4 +5V 1N4148 100 33K C405 7 REM PADCA U4 J402 .001 D401 PAI (Jumper under board) 5 1.00V = 10.0A 13 INPUT U402B 12 J2-3 14 13 12 PADC LAMP RF REV TL072 11 12 J3-14 RF FWD C406 R405 R416 10 U404D U405F RFV .01 2.49K 1 100K 9 R407 TL074 74HC14 VOLTMETER D408 8 10.0K 1 11 10 FAULT SUM FAN R425 R415 7 J4-8 TEMP OUT 1M 120K U405E 6 J2 74HC14 5 R408 +12V PAV 4 1.1K 1 1 2 PATEMP LAMP PAI C407 3 U3 J3-12 DC SUPPLY 4 .001 D402 2 2 U405A /+28V INH 1 74HC14 1 C421 50mv per degree C. 3 +5V .001 U403A R429 R432 RECEPT 12X1 R422 11 TL074 220K 100K 75k HD403 R492 D409 R424 C408 R431 SEL A R420 -12V 10K 2 1 -12V 100k 1.0UF 120K SEL B 4 3 100K 1 R423 U3 R430 SEL C 13 6 5 240K R426 100K RF LEVEL 14 FAN /LOCK 3 4 LOCK LAMP 8 7 30.1K 1 +5.00V +5.00V 12 J2-7 J4-1 J3-18 10 9 U403D PATEMP LAMP U3 R421 U405B D411 12 11 TL074 PADC LAMP R418 9 J4-6 74HC14 /+28V INH 14 13 100 R427 D410 INPUT LAMP J3 8 REM PATEMP J2-1 16 15 1K 240K C409 LOCK LAMP DPM REF TEMP OUT 10 R428 +12V R437 18 17 -12V .001 SWR LAMP DPM IN J2-6 U403C 5.00V = 100 deg. C 10K 1M 20 19 TL074 4 D403 C431 2 U4 INPUT 5 6 INPUT LAMP HEADER 10X2 0.1 10mV/Deg. C 1 J2-12 J3-16 R436 3 U405C R419 U404A R439 74HC14 24.9K R435 24.9K 100K 100K 11 TL074 D412 J404 +5.00V R438 12 RF LEVEL 11 120K D405 J3-8 C411 R446 GND 10 R440 -12V R441 10K 9 0.1 FAULT SUM (R435+R436)+R436 150K 33K 1M 8 R434 REM BATT SWR LIMIT= ------= ---- = 1.5:1 7 10K POT H REM PATEMP (R435+R436)-R436 100K R445 100K 6 J4 R443 REM RFWATTS 5 C410 51K REM PADCA 4 0.1 REM PADCV POWER SET U4 R442 3 9 D404 ALC 51K U4 R447 2 6 /LOCK DC SUPPLY 8 1K 1 J2-2 10 7 ALC U404C 5 J4-2 RECEPT 12X1 TL074 R444 U404B R451 R454 R448 6 200K TL074 100K 1 U3 100 100K 1 7 REM BATT 5 J4-7 U403B -12V C412 TL074 R449 R452 11K 1 0.1 10K 1 +5V FULL SCALE (1.999V reads "1999") 16 .001V per Watt RF POWER (RFV SQUARED) RF POWER 1999 WATTS 13 3 DPM IN R453 X0 X SWR 19.99 14 J3-19 X1 1.1K 1 ALC 19.99V 15 C422 X2 10mV/Volt PA DCV 199.9V 12 0.1 X3 100mV/Amp PA DCI 19.99A 1 X4 1mV/Degree C PA TEMPERATURE 199.9 Deg. C 5 R455 X5 10mV/Volt SUPPLY DC VOLTS 199.9V 2 100K 1 X6 U8 VOLTMETER 10mV/Volt VOLTMETER 199.9V 4 X7 J2-8 U408 C413 6 R456 INH 74HC4051 0.1 11 A 1K 1 10 R467 B (VFWD+VREFL)/40 9 C U406A +12V 1K POTH TL074 8 R466 4 R465 +5.00V NUMBERS USED: D413 56K R457 2 U6 R460 56K SWR CAL R488 R1-91 10K 1N6263 R468 1 24.9K C1-29 (C2) RF REV 3 1K R490 J2-11 1 1K +5V 1 C415 R459 10.0K 1 R486 .001 100K C414 100K 16 -12V 13 13 3 DPM REF .01 U6 X0 X 14 (VFWD-VREFL)/4 14 J3-17 X1 12 15 C423 X2 U406D 12 0.1 X3 R458 100K TL074 1 X4 22K R487 R489 1.00V 5 X5 24.9K 2 R484 D418 X6 U9 Q403 4 10K 2N5210 X7 U406B R491 U409 6 TL074 2.49K 1 INH 74HC4051 J3-2 SEL A 11 D414 A R461 6 J3-4 SEL B 10 U6 1N6263 B 10K 7 +5.00V J3-6 SEL C 9 +5.00V C RF FWD 5 J3-9,10 J2-10 R464 J4-12 8 C417 R463 1K C416 .001 100K D417 .01 +5V R485 R462 LM394 100K VDD 22K 1 8 C1 8 C R481 VR401 2 7 B2 7 B 39K C424 +12V 78L05 VCC 3 6 DZ402 C420 E3 6 E R476 R483 1.0UF 4 5 +12V 1 3 LM329DZ .01 4 5 49.9K 1M IN OUT +5V Q405 -12V C425 C U8,9 pin 7 U407A +12V POWER CAL D416 C426 -6.9V TL074 LM394 1.0UF 2 1.0UF C429 1 8 9 1.0UF 4 U7 D415 C1 8C U7 R417 2 R472 2 7 8 (2.5VDC at 100W) 9 R469 1N6263 B2 7B U6 VSS 3.3K 1 10K POT H 3 6 10 8 10K E3 6E -12V FM500 RFV 3 4 5 U407C (.135V) 10 R473 C427 VEE Q4064 5 U406C C428 J2-9 10K U7 TL074 R479 1.0UF METERING 11 C419 R471 6 TL074 1.0UF -12V 1.1K 1 R482 C418 .001 100K 7 R477 1K 103204A .01 -12V 5 (Clamp SWR reading below 5W.) R474 7.5K U407B 3.3K TL074 R475 R478 R470 49.9K 10.0K 1 U7 R480 22K 13 100 J4-5 14 REM RFWATTS 12 (1.00V at 100W) -6.9V U407D TL074 METERING Reference Drawings 6–11

DWG. NO. REV. 1 2 3 4 5 6 7 8 9 10 11 12 201207-SCH 1 5 6 REVISION HISTORY APPROVALS E . C . N. REV DESCRIPTION DATE DWN CHK CM PE

+12V 1 FOR PROTOTYPE 02-05-05 DW DW HD7 FAN AUDIO PROCESSOR SHUNT FAN- 1 R42 +12V 2 4.7K HEADER 2 .156 ALC / METERING RF EXCITER +12V H H C52 C50 HD2 U2 .01 +5.00V +12V 1 8 1 C54 NC NC 1.0 2 2 7 2 Z9 3 Vin NC TL072 1 R43 4 3 6 3 U3A 5 1.0 TEMP Vout 100 OPEN 6 C51 4 5 C54 GND TRM -12V HEADER 6X1 .156 J4 J2 J1 J1 1.0 1.0 C25 C26 C27 R25

Q1 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 .01 .01 .01 OPEN REF02 IRF541 HD44 HEADER 12 HD42 HEADER 12 HD41 HEADER 5 x 2 HD31 26 HEADER R26 J5 J6 TP1 +12V 6 TL072 1 2 3 4 5 6 7 8 9 10 11 12 +5.00V 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 MCX MCX 7 VOLTMETER 1K 5 U3B C10 +12V

.01 NC NC

-12V /LOCK FAULT DC SUPPLY PAI PAV TEMP FAN V-METER RFV RF FWD RF REV INPUT FSK IN /LOCK /LOCK ALC METER PAV METER PAI METER RFW METER PATEMP METER BATT FAULT SUM G HD4 G R29 1K -12V 1 Z31 ALC 2 R28 1K OPEN 3 ADD FOR M2HD-S RFX OUT AUDIO PROCESSOR 4 R27 1K MOTHERBOARD ONLY 5 6 /LOCK 7 8 ALC 9 10 HEADER 5 x 2

HD12 COMP OUT 1 1 +12V NC 2 2 3 3 HD5 LEFT C41 4 4 V+ 1 5 5 FSK IN TEMP 2 .001 NC 6 6 3 7 7 J2 GND RIGHT +5.00V +12V C42 8 8 HEADER 3X1 9 9 .001 NC 10 10 HD13 HD61 F F HEADER 5 x 2 1 1 1 C43 +12V 2 2 2 .001 3 3 3 -12V 4 4 4 5 5 5 HD11 /+6DB 6 6 6 1 1 7 7 7 L IN1 /+12DB 2 2 8 8 8 METER PAI METER RFW METER PATEMP METER BATT FAULT SUM ALC METER PAV 3 3 9 9 9 L IN2 L VU 4 4 10 10 10 INPUT 5 5 11 11 11 R IN1 R VU 6 6 12 12 12 TEMP 7 7 13 13 13 R IN2 J3 +5.00V 8 8 14 14 14 9 9 15 15 15 HD3 PROC A 10 10 J1 16 16 16 1 11 11 17 17 17 LPIN L PROC B 2 12 12 18 18 18 3 13 13 19 19 19 NC LPOUT L PROC C 4 NC 14 14 20 20 20 5 15 15 21 21 LPIN R BR GR 6 16 16 22 22 HEADER 10 x 2 7 17 17 23 23 LPOUT R HI GR 8 18 18 24 24 9 19 19 25 25 NC NC 10 Z30 20 20 26 26 Z32 Z33 11 C17 E 12 HEADER 10 x 2 HEADER 13 x 2 E 13 JUMPER .01 OPEN OPEN -12V 14 NC Z29 INSTALLED WHEN USING 15 NC C18 AUDIO PROC. SHUNT CKT. 16 COMP METER COMP METER 17 NC JUMPER .01 18 Z28 19 NC ALC C19 20 JUMPER .01 STEREO/MON HEADER 10 x 2 +12V Z27 C20 C40 JUMPER .01 TP2 OPEN Z26 C39 C21 +12V OPEN JUMPER .01 STEREO GENERATOR C38 Z25 TP3 OPEN C22 -12V JUMPER .01 C36 Z24 .01 C23 +5.00V C35 JUMPER .01 HD22 +12V

.01 COMP OUT 1 1 Z23 MON L 2 2 D C34 C24 MON R +5.00V D 3 3 .01 JUMPER .01 NC 4 4 5 5 C33 LPIN L 6 6 LPOUT L TP4 .01 7 7 J2 LPIN R 8 8 C32 LPOUT R +12V +12V 9 9 .01 10 10 38KHZ 38KHZ HD23 C30 11 11 12 12 1 1 COMP METER COMP METER TP5 .01 2 2 HEADER 12 3 3 C31 /EXT ENABLE /EXT ENABLE GND 4 4 .01 5 5

LEFT RIGHT J3 6 6

C29 OPEN OPEN OPEN OPEN OPEN OPEN OPEN OPEN 7 7 .001 8 8 C28 9 9 10 10

.001 STEREO/MON Z15 Z16 Z17 Z18 Z19 Z20 Z21 Z22 HEADER 5 x 2 220 220 220 220 220 220 220 220 -12V ALC HD21

R24 R23 R22 R21 R20 R19 R18 R17 1 1 D1 2 2 C 3 3 C 1N4148 4 4 5 5 6 6 J4 L IN1 R IN1 L IN2 R IN2 7 7 J1 8 8 8 _METER PAV 9 9

EXT IN EXT RTN SCA IN 10 10 15 _METER PAI 11 11 12 12 7 _METER RFW HEADER 12 NOTES: 14 _METER PA TEMP Z6 OPEN C9 220pF UNLESS OTHERWISE SPECIFIED: 6 _METER BATT R1 R IN1 R3 1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% TOL. 13 _FAULT SUM 1K 1K C8 Z4 OPEN 220pF 2. ALL CAPACITORS ARE IN MICROFARADS. 5 _/AUTO CAR. OFF R2 L IN2 R4 COMP METER 12 _/CARRIER OFF C5 1K 1K R16 220 220pF Z13 4 _FSK IN FSK IN STEREO GENERATOR SHUNT R40 11 _ALC R15 100 C3 C4 C6 Z1 Z2 COMP OUT OPEN 100 R14 390 220pF 220pF 220pF 3 _COMPOSITE OUT COMP METER JUMPER JUMPER Z12 B 10 _38 KHZ OUT R13 390 C2 C1 C7 R39 B 220pF 220pF 220pF OPEN 2 JMP1 OPEN 100 R12 1K JMP2 OPEN Z5 Z7 R9 R8 R5 R6 R7 Z14 9 _/EXT ENABLE 1K 1K 1K 1K 1K R1A R3A SCA IN R41 1K 1 R11 220 /EXT ENABLE OPEN 300 300 OPEN OPEN D3 C11 C12 C13 C14 C15 C16 D2 DB15 Z3 Z8 R10 Z11

R4A R33 R34 24.9K 1% 1N4148 .01 OPEN .001 .001 .01 .01 R2A EXT RTN R32 240 OPEN 300 OPEN OPEN 1K R38

300 24.9K 1N4148 1% C48 +12V 4.02K MON_R MON_L EXT_IN EXT_RTN SCA 1.0 1% 2 TL072 Z10 1 R37 6 TL072 EXT IN R35 3 U1A 7 HD6 1 2 3 4 5 J2 3.9K 5 U1B J1 3 2 1 1 2 3 OPEN OPEN 24.9K C49 XLR OPEN -12V 1% 1.0 R36 IREC APPROVALS 24.9K INTERNATIONAL RADIO AND ELECTRONICS CORP. INPUT CONFIGURATION CHART 25166 LEER DRIVE ELKHART, IN. 46514 HI 1% DWN DW 11-23-04 2 Error : logo3A.jpg file not found. LO 574-262-8900 WWW.IREC1.COM NON-OMNIA BOARD INPUT IMPEDENCE OMNIA BOARD AES/EBU INPUT 3 CHK A GND A 1 TITLE: 50 KOHM 600 OHM Z1, Z2 OFF CM DW 11-23-04 REF. FOR SCH, FM/IBOC MOTHER BOARD Z1, Z2 ON Z1, Z2 ON Z3, Z5, Z7, Z8 OFF UNCONTROLLED Z4, Z6 ON XLR CON. THESE DRAWINGS AND SPECIFICATIONS ARE THE PE Z3, Z5, Z7, Z8 OFF Z3, Z5, Z7, Z8 ON UNLESS OTHERWISE MARKED IN RED INK BY CM AS A PROPERTY OF INTERNATIONAL RADIO AND ELECTRONICS CORP. SIZE DWG . NO . REV Z4, Z6 OFF Z4, Z6 OFF CONTROLLED COPY, COPIES OF THESE DOCUMENTS AND SHALL NOT BE REPRODUCED, COPIED OR USED AS DISTRIBUTION ANALOG LEFT/RIGHT D 201207-SCH 1 LEFT IN 1 LEFT IN 2 INCLUDING ASSOCIATED ELECTRONIC REPRODUCTIONS THE BASIS FOR THE MANUFACTURE OR SALE OF APPARATUS OR K ARE FOR REFERENCE ONLY. DEVICES WITHOUT PERMISSION. FILENAME: SCALE : NONE PROJ NO. SHEET 1OF 1

1 2 3 4 5 6 7 8 9 10 11 12 Jumper FMA "E" FMA "T" FMA"T" FMA "R" FMA "Omnia" FMA "Omnia" FMX "E" FMX "T" FMX "T" FMX "R" FMX "Omnia" FMX "Omnia" FMX 50K input 600 input Analog input AES input 50K input 600 input Analog input AES input RMS Z1 Short Short Short Short Short Open Short Short Short Short Short Open Z2 Short Short Short Short Short Open Short Short Short Short Short Open Z3 Open Open Short Open Open Open Open Open Short Open Open Open Z4 Open Open Open Open Open Short Open Open Open Open Open Short Z5 Open Open Short Open Open Open Open Open Short Open Open Open Z6 Open Open Open Open Open Short Open Open Open Open Open Short Z7 Open Open Short Open Open Open Open Open Short Open Open Open Z8 Open Open Short Open Open Open Open Open Short Open Open Open Z9 Short Open Open Open Open Open Short Open Open Open Open Open Z10 Short Open Open Open Open Open Short Open Open Open Open Open Z11 Short Open Open Open Open Open Short Open Open Open Open Open Z12 Short Open Open Open Open Open Short Open Open Open Open Open Z13 Short Open Open Open Open Open Short Open Open Open Open Open Z14 Short Open Open Open Open Open Short Open Open Open Open Open Z15 Open Open Open Open Open Open Open Open Open Open Open Open Short Z16 Open Open Open Open Open Open Open Open Open Open Open Open Short Z17 Open Open Open Open Open Open Open Open Open Open Open Open Short Z18 Open Open Open Open Open Open Open Open Open Open Open Open Short Z19 Open Open Open Open Open Open Open Open Open Open Open Open Short Z20 Open Open Open Open Open Open Open Open Open Open Open Open Open Z21 Open Open Open Open Open Open Open Open Open Open Open Open Open Z22 Open Open Open Open Open Open Open Open Open Open Open Open Open Z23 Short Short Short Short Short Short Short Short Short Short Short Short Open Z24 Short Short Short Short Short Short Short Short Short Short Short Short Open Z25 Short Short Short Short Short Short Short Short Short Short Short Short Open Z26 Short Short Short Short Short Short Short Short Short Short Short Short Open Z27 Short Short Short Short Short Short Short Short Short Short Short Short Open Z28 Short Short Short Short Short Short Short Short Short Short Short Short Short Z29 Short Short Short Short Short Short Short Short Short Short Short Short Short Z30 Short Short Short Short Short Short Short Short Short Short Short Short Short Z31 Open Open Open Open Open Open Open Open Open Open Open Open Z32 Short Open Open Open Open Open Short Open Open Open Open Open Z33 Short Open Open Open Open Open Short Open Open Open Open Open JMP1 Open Open Open Open Open Open Open Open Open Open Open Open Open JMP2 Open Open Open Open Open Open Open Open Open Open Open Open Open R27

D 8167-5

Illustration 6–10 Display Board (Add 600 to component designators for schematic reference)

6–14 FM500 User's Manual U602 DL601-610 JP601 LM3915 +5V 9 10 +12V MODE L10 U613B +12V RED +5V R602 TL072 8 11 6 100K RADJ L9 YEL Q604 +12V R604 G G G G Y R645 C611 7 100 1.2K 7 12 DL621-625 2N5087 0.1 5 ROUT L8 GRN +12V R601 D601 DL648-658 C628 8 1N4148 6 13 C626 JP603 68K 5.00V DHI L7 GRN R644 1.0UF L VU 2 R603 1.0UF JUMPER 1K 5 50mA R646 U608 1 14 33K FOR BAR 3 IN L6 GRN 10M LM3914 R652 C601 C602 1 1 1 1 1 1 1 1 1 "110" 4 5.6K 1.0UF U601A D602 1.0UF 15 8 7 6 5 4 3 2 1 0 9 10 4 DLO L5 GRN D605 MODE L10 RED TL072 1N4148 L L L L L L L L L 3 16 COMPOSITE -12V R627 8 11 +12V V+ L4 GRN 2 3 4 5 6 7 8 9 1 RADJ L9 YEL 0 2.7K -12V 2 17 +5V 1N6263 7 12 V- L3 GRN U604 LM3914 R622 R643 ROUT L8 GRN 10.0K 1 R R M R623 3.3M 6 18 D D O A O 5.00V 13 L1 L2 GRN L V V L I H U D D 10.0K U613A DHI L7 GRN 1 - + O N I T J E TL072 5 14 IN L6 GRN 1 2 3 4 5 6 7 8 9 +12V +12V R606 U607B R648 R653 D618 4 15 RED D606 1K 6 TL072 DLO L5 GRN R605 330 R614 8 8 1K 2 1N6263 7 Q603 2 3 16 1K R613 V+ L4 GRN +12V U607A 1 5 2N5210 1 1K 1.2K +12V HI GR TL072 3 3 2 17 Q601 R647 V- L3 GRN 5.00V MPS-A56 C605 C610 4 1K 4 1 18 .001 0.1 L1 L2 GRN +5V R624 C612 U603 D607 JP602 DL11-20 -12V 1M .001 -12V GRN LM3915 R626 9 10 C606 GRN +12V MODE L10 RED Y Y G G G G G G Y RED 33K R608 0.1 100K 8 11 DL626-635 "PILOT" R610 RADJ L9 YEL R625 1.2K 7 12 10K C603 ROUT L8 GRN R629 R649 DITHER 1.0UF R607 D603 R615 1 1 1 1 1 1 1 1 1 MOD. CAL. 680 6 13 8 7 6 5 4 3 2 1 0 10K POT H 68K 1N4148 5.00V DHI L7 GRN 33K C625 R VU 6 R609 0.1 50mA L L L L L L L L L 7 1K 5 14 IN L6 GRN 2 3 4 5 6 7 8 9 1 SW603 5 DITHER 0 STEREO C604 4 R655 U601B D604 15 U605 LM3914 1.0UF DLO L5 GRN 4.7K +5V TL072 1N4148 5.00V ST/MON 3 R R M DL644-647, 659 +12V 16 D D O A O MONO V+ L4 GRN L V V L I H U D D R616 2 17 +5V 1 - + O N I T J E SWR V- L3 GRN 33K SWR LAMP 1 2 3 4 5 6 7 8 9 C634 1 18 1.0UF L1 L2 GRN DL644 R657 RED 1K BECKMAN RF LEVEL C607 R618 RED R612 0.1 +12V 1.2K LOCK LOCK LAMP BR GR R611 330 PROC A 1K R617 DL645 1K C608 SW601 Q602 5.00V RED /+6DB .001 PROC B R650 MPS-A56 100K BECKMAN INPUT PROC C INPUT +5V SW602 DL646 U609F /+12DB RED C613 74HC14 +12V .01 PA DC PADC LAMP 12 13 R633 2 8 R631 5.6K 33K R619 1 6 DL647 510 3 7 DITHER RED 5 4 U606A 10V P-P DITHER 2 1 1 1 1 1 1 1 1 1 1 PA TEMP TL072 D616 D617 R620 0 9 8 7 6 5 4 3 2 1 0 123456789 PATEMP LAMP C609 R632 U606B 220K -12V 1.0UF DL101 620 TL072 DL659 DISPLAY RED 1000 100's TENS UNITS +5V DP10 R634 DECIMAL POINT 5.1K DP100 R656 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 4 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 220 DL636-643 Pin 1, upper left from front of unit. F.S. GRN J601 +5V DP10 +12V +12V +12V RF POWER 1999 2 1 +12V DP100 +12V -12V -12V C631 4 3 -12V GRN L VU /+12DB 1.0UF 6 5 R VU /+6DB SWR 19.99 8 7 5.00V 5.00V VR601 10 9 VDD GRN PROC A 7805 12 11 1 VCC PROC B 3 ALC 19.99 14 13 IN OUT +5V PROC C COMPOSITE C623 16 15 C C624 C629 GRN BR GR 1.0UF 1.0UF 1.0UF 14 16 18 17 2 HI GR MON/ST PA DC VOLTS 199.9 20 19 U9 U10 U11 GRN GND U611 7 HEADER 10X2 PA DC AMPS 19.99 74HC4051 8 GRN 13 3 -12V X0 X +5V -12V VEE 14 PA TEMPERATURE 199.9 X1 2 1 1 1 1 1 1 1 1 1 1 VSS 15 C622 C630 X2 R630 0 9 8 7 6 5 4 3 2 1 0 123456789 GRN 12 J602 1.0UF 1.0UF X3 150 1 SEL A SUPPLY DC VOLTS 199.9 X4 2 1 5 SEL B X5 4 3 GRN 2 SEL C U612 ICL7107 X6 6 5 4 RF LEVEL VOLTMETER 199.9 X7 8 7 5.00V 5.00V 10 9 6 PATEMP LAMP INH 12 11 11 PADC LAMP 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 4 U609A A 14 13 UP C620 10 INPUT 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 R628 74HC14 B 16 15 SW605 .01 9 LOCK LAMP DPM REF C627 R651 1K C 18 17 1 2 SWR LAMP DPM IN 1.0UF 2.2K 20 19 -12V U610 C632 R639 R641 74HC193 HEADER 10X2 100K .001 DZ601 +5V 10K 15 3 SEL A A QA 6.2V 1 2 SEL B R638 U609C U609B B QB DOWN C621 10 6 SEL C 100K 74HC14 R654 74HC14 C QC C618 SW606 .01 9 7 5 1K D QD 0.1 6 3 4 5 12 UP CO 4 13 R640 C633 DN BO R642 11 C616 C617 U609D 100K .001 LOAD 10K 14 0.1 POLY 0.1 C619 74HC14 CLR R635 R637 100PF 9 8 +5V SCM, FM DISPLAY 100K 470K DPM IN NOTES : U609E 1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% UNLESS OTHERWISE SPECIFIED. C614 103206 0.1 74HC14 2. ALL CAPACITORS ARE IN MICROFARADS UNLESS OTHERWISE SPECIFIED. R636 11 10 100K DPM REF C615 0.1 DISPLAY

Reference Drawings 6–15

CARR SW R701 4.7K R702 U703C 10K /CARRIER OFF 5 6 +12V CROWN INTERNATIONAL, INC. R733 1718 WEST MISHAWAKA ROAD ELKHART, IN. 46517 PHONE (219) 294-8000 4.7K VDD 74HC14 R723 R703 D701 1K 4.7K 1N4148 FM VOLTAGE REGULATOR U703A U703B D702 +6V R704 1N4148 VDD 10K /AUTO CARRIER 1 2 3 4 DRAWN JFL 8-25-97 APPROVED BY : DO NOT SCALE PRINT VCC DZ701 1N4735 CHECKED ME SUPERSEDES 74HC14 74HC14 +12V 6.2V D707 Fo=5KHZ BPF; Q=3 1N4148 SCALE NONE EE E.C. VSS R713 R709 PROJ # MLOWCMO PE DWG. NO. REV C702 1K 100K R722 R707 U702 .001 +12V 100K 180K 74HC4060 FILENAME: 10.SCM NEXT ASM: 103207 A 11 7 R705 D706 R716 PI Q4 4 6 5 91K D703 R708 1N4148 10K Q5 2 7 12 4 TIME-OUT 1N6263 100K RST Q6 1 5 6 SELECT Q7 NOTES : 3 U701B 14 U703D ______C703 Q8 D708 ______THESE DRAWINGS AND SPECIFICATIONS ARE THE U701A TL074 13 MINUTES JP701 .001 Q9 1N4148 1. ALL RESISTORS ARE IN OHMS, PROPERTY OF CROWN INTERNATIONAL, INC. AND R706 1 TL074 15 0.5 9 8 28V ENABLE Q10 2 1 1/4W, 5% UNLESS OTHERWISE SPECIFIED. SHALL NOT BE REPRODUCED, COPIED, OR USED 5.1K 1 R715 1 2 R714 Q12 4 3 AS THE BASIS FOR THE MANUFACTURE OR SALE C701 2.2K 2 4 2. ALL CAPACITORS ARE IN 220 Q13 6 5 OF APPARATUS OR DEVICES WITHOUT PERMISSION. AUDIO or COMPOSITE .01 -12V 3 8 74HC14 MICROFARADS UNLESS OTHERWISE SPECIFIED. Q14 8 7 COMP2 INPUT FAULT 10 9 R717 9 PO 10K 10 PO HEADER 5X2 D704 R710 R711 DL701 75K 13 1N6263 100K DL702 R721 14 GREEN R718 1 RED 100K 24.9K 12 1 C706 U701D VDD 1.0 R712 C705 TL074 POLY Modifications for use C704 1M 1.0 .001 POLY with 12.5V RF driver. R719 10K PROGRAM DETECT Remove: (C707) (R726) 9 (R708) 8 (R749) 10 U701C U706 TL074 L704 R720 R745 10K R744 C724 D713

R724 100 P701 +UNREG Change: R732 100K to 49.9K D714 1N5822 to MUR110 DZ703 1.5KE36A to ICTE-12 R734 C721, C722 3300UF to 220UF/50V 10K Q705 Add: 1UF/100V between L701 and L703 under board. MPSA06 7912 regulator, using "L704" pads. DZ702 Jumper "U706" pads 1 and 2. U1 LM3578 U2 IR2125 DZ705 1N9661B C723 D710 330 C712 16V 1N4148 100V 1 -IN V+ 8 1 VCC VB 8 U704 1.0 LM3578 2 +IN CS 7 2 IN OUT 7 1 8 U705 1 8 C714 2 7 IR2125 2 7 0.1 R735 3 OSC C 6 3 ERR CS 6 3 6 1 8 Q701 3 6 1 8 51 4 5 2 7 IRF540 4 5 2 7 4 GND E 5 4 ESS VS 5 3 6 C711 3 6 4 5 C709 .01 4 5 2200PF C713 R737 R738A R738A R730 100PF C715 R736 POLY 4.3K 1.0 1.0 2.2K 0.1 2K 0.5W 0.5W Q704 MJE15028 R728 (+13.5V) (+12.5V) DRVR V+ C710 68K L701 D709 56PF VDD VDD 380UH R740 Q703 R743 OPEN NPO 10 R739 MPSA56 220 D711 C718 DZ703 C725 220 510 220 R725 R748 MUR110 ICTE-12 63V C717 63V 100K 10K 1UF

R749 R732 1.5K C719 13 12 11 10 82.5K 1000 R741 1 35V 1K U703E C707 U703F C708 220 Pf 74HC14 .001 74HC14 R727 620 R729 U706 R726 4.12K LM2576–ADJ 100K 1 Q702 1 2 3 4 5 MPSA06

R742 1K R744 R750 1.1K 1% CARR SW -12V 100 DRVR V+ +12V METER UNREG +UNREG R745 10K 1% L702 +12V 960UH +12V INPUT FAULT +12V SYNC 6 5 4 3 2 1 6 HD701 -12V 5 DRVR V+ 4 HD704 C720 PAV DZ704 3 D713 220UF PAI ICTE-12 2 1N5822 50V /LOCK FAULT ALC 1 R751 Inductor Data JUMPER HEADER 6 (TO POWER REG. BOARD) C724 L701 L702-703 1 3 5 7 9 1 1 1 1 1 47 D715 D714 1 3 5 7 9 20V L704 -12V 1N4004 HD702 1N5822 1 1 1 1 1 2 L 380uH 960uH 960UH 2 4 6 8 0 2 4 6 8 0 -12V 1 2 3 Wire #22 #26 HD703 Tur ns 80 165 L703 FAN 960UH C721 C722 c 8667-5 A10124-22 3300UF 3300UF COMP2 16V 16V 38KHZ Micrometals T90 core /CARRIER OFF /AUTO CARRIER VOLTAGE REGULATOR

Reference Drawings 6–17 Illustration 6–12 Power Regulator Board

6–18 FM500 User's Manual B_L_SHT1_A.DOT REV.A C D A E B F C10582-2 PA VOLTAGESET PWB_100969-1 PWB_REV.G 1 1 R802 10K REF DES

DZ807 DZ806 R828 R827 R811 L802 3 1 R801A R801B 27.4K 24.9K 220PF C801 2 - 2 2 C802 ~ ~ * * ON CHASSIS + Z1 Z2 CIRCUIT BREAKER

JUMPER 2200PF POLY C803 56PF Z2 Z1 1 Z9 Z5 Z4 Z6 Z7 Z8 Z3 1 1 110V 0.015F C1001 10.0K 1% R804 C804 * 1N4735 6.2V .01 DZ806 BATTERY 1 1 1 1 *

R803 Z3 DC INPUT 4681H39- H43533-1 H43395-5 H43608-1 2 2 HR HR HR SHORT OPEN SHORT SHORT OPEN SHORT OPEN OPEN SHORT SHORT OPEN SHORT OPEN OPEN OPEN OPEN OPEN SHORT HR HR HR HR SHORT SHORT SHORT SHORT SHORT * * * * FM1 .K3.3K 3.3K Z8 Z9 Z6 Z7 82K 2 4 3 2 1 2 2 2 2 OPEN OPEN OPEN OPEN R805A R806A R805B R806B 330K 330K 200K 200K GND OSC +IN -IN SHORT ARE FORREFERENCEONLY. INCLUDING ASSOCIATEDELECTRONICREPRODUCTIONS CONTROLLED COPY,COPIESOFTHESEDOCUMENTS UNLESS OTHERWISEMARKEDINREDINK BYCMASA OPEN OPEN OPEN HR HR SHORT SHORT SHORT FM30 FASTON TAB FASTON TAB FASTON TAB FASTON TAB FASTON TAB FASTON TAB FASTON TAB P807 P805 P804 P803 P802 P801 P806 LM3578AN * 1.0K R827 U801 + UNREGIN 1N4148 CS V+ D805 E C OPEN OPEN OPEN OPEN 1/50V C814 FM100 PNOE OPEN SHORT OPEN OPEN OPEN SHORT OPEN OPEN SHORT OPEN HR HR SHORT SHORT SHORT 3.3K 7 8 5 6 UNCONTROLLED DZ801 330/100V 1 R820 100K OPEN OPEN OPEN OPEN C815 2.2K R807 3 3 FM250 4.7UF/63V

* 2 OPEN 4531H43533-1 H43533-1 OPEN C806

3.3K 3 + BYV72EW-150 UNIT CONFIGURATION 1N966B 16V D804 + 100PF C805 OPEN OPEN OPEN OPEN FM500 SHORT OPEN OPEN SHORT 30UH L801 330/100V 3.3K 4 3 2 1 C816 1/50V C812 ESS ERR IN VCC IR2125 OPEN OPEN OPEN OPEN U2 1N966B 16V + 5.11K 1% H43533-1 EURO SHORT OPEN SHORT OPEN SHORT OPEN SHORT SHORT OPEN * OUT VB VS CS DZ807 5 6 7 8 + DEVICES WITHOUTPERMISSION. FOR THEMANUFACTUREORSALEOFAPPARATUS OR AND ARENOTTOBEREPRODUCED,COPIED ORUSEDASTHEBASIS INTERNATIONAL RADIOANDELECTRONICS CORP. THESE DRAWINGSANDSPECIFICATIONS ARETHEPROPERTYOF HARRIS M1 330/100V NTLE INSTALLED INSTALLED INSTALLED INSTALLED INSTALLED INSTALLED INSTALLED C817 H43533-1 4 4 SHORT OPEN SHORT OPEN SHORT OPEN OPEN SHORT OPEN 3.3K .1 C809 1N4148 D802 .0027 C808 HARRIS M2 INSTALLED H43533-1 SHORT SHORT OPEN OPEN SHORT OPEN OPEN SHORT 3.3K * R808

3 R809 1.0K R828 51.0 30K 2 1 2.0K R810 BYV72EW-150 D803 R811 * E .CN. R812A W5W 5W 0.1 323 274 5 5 R812B IRF540 Q801 0.1 REV L802 B C A * MICROFARADS. 2. ALLCAPACITORSAREIN 1/4W,5%TOL. 1. ALLRESISTORSAREINOHMS, SPECIFIED: UNLESSOTHERWISE NOTES: CORRECTED Z3ANDZ6UNITSTATUSFORM2FM100 SWAPPED Z1,Z2TOMATCHPWB PRODUCTION RELEASE + 330/100V C810 30UH L803 REVISION HISTORY FILENAME: C811 DWN CHK CM PE + DESCRIPTION 6 6 DISTRIBUTION 200915-SCH APPROVALS 330/100V DP DW DW 2.0K R818A 2W R818B 10.0K R821 2.0K 22.0K 2W 09-30-03 09-30-03 09-30-03 R814 1N4735 6.2V DZ803 OPEN 1N966B 16V DZ802 TITLE: SIZE B C813 .01UF 3 2 Error :logo3A.jpgfilenotfound. IREC 574-262-8900 25166 LEERDRIVEELKHART,IN.46514 INTERNATIONAL RADIOANDELECTRONICSCORP.

DWG .NO 4 7 100.0 1 R815 OP-27GNB U803 MPSA06 Q804 MPSA56 Q802 SCH, FMPOWERREGULATOR 7 7 8 1.0K R813 01-29-04 08-10-04 10-31-03 .04 OHM15W3% DATE 6 SCALE :NONE R819 .1UF C818 TP1 DWN DW DW DW .01UF C819 WWW.IREC1.COM 200915-SCH R817B R817A 1.0K 1% R816 100 2W PROJ NO. 2K 2N5087 Q803 CHK APPROVALS TP2 22.0K R822 1 1 * * 533 Z5 Z4 0.01UF DISK CM DW DW DW C820 8 8 2 2 DP DP DP PE FASTON TAB SHEET PA-DC OUT C 7527-2_6HDR HD1 6 5 4 3 2 1 1 1 P808 OF REV. C A B C E DWG. NO. 200915-SCH REV. C F R20 R19

Illustration 6–13 Power Amplifier (Add 1100 to component designators for schematic reference)

6–20 FM500 User's Manual THESE DRAWINGS AND SPECIFICATIONS ARE THE PROPERTY OF CROWN INTERNATIONAL, INC. AND SHALL NOT BE REPRODUCED, COPIED, OR USED CROWN INTERNATIONAL, INC. AS THE BASIS FOR THE MANUFACTURE OR SALE C909 L904 L903 1718 WEST MISHAWAKA ROAD ELKHART, IN. 46517 PHONE (219) 294-8000 U900 OF APPARATUS OR DEVICES WITHOUT PERMISSION. 23.2uH 10.4uH 680PF R900 CA2832 MRF 137 C903 9875321 0.01 FM500 P.A. T900 C908 C907 C910 C906 C905 L902 27PF 5PF 36PF 36PF 10PF J2 R900 DRAWN JFL 7-12-96 APPROVED BY : DO NOT SCALE PRINT 51 CHECKED ME SUPERSEDES

C900 SCALE NONE EE E.C. R901 0.01 DWG. NO. REV R903 51 4.7K PROJ # R103 PE RF DRIVER BD L900 A 33uH FILENAME: 1001771A.SCM NEXT ASM: 100177

R904 C902 D900 51 0.01 1N753A R902 6.2V R905 10K 2.7 C901 C904 5W NOTES : 0.01 ______0.01 1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% UNLESS OTHERWISE SPECIFIED. J3 J5 2. ALL CAPACITORS ARE IN MICROFARADS UNLESS OTHERWISE SPECIFIED.

C1126 0.1 J1 1 37 2 38 3 39 L1121 4 40 R1101 50NH 5 41 15K 6 42 DZ1110 R1110 R1120 C1110 C1121 C1122 7 43 1N4735 0.01 0.01 8 6.2V 10K 2.7K 0.01 44 DISC DISC 9 45 TEMP SENSE 10 46 LM35DZ 11 47 123 12 48 R1111 13 49 10K C1132 14 50 POT V 15 0.1 51 C1111 L1122 16 52 0.01 50NH 17 53 R1112 18 54 R1113 19 55 5.6 5.6 20 56 2W 2W Q1101 21 57 BLF278 22 58 C1127 C1128 C1133 C1134 C1135 C1136 R1116 23 59 0.1 0.1 0.1 0.1 0.1 0.1 10K 24 60 C1112 C1113 25 61 T1111P 0.01 0.01 26 62 C1137 27 63 0.1 C1125 28 64 R1119 C1116 R1117 60PF 29 65 24 200 27PF 30 66 3W 3W 31 67 T11S C1138 C1123 C1124 32 68 0.068 0.01 0.01 33 69 T1121 34 70 C1114 C1115 35 71 0.01 0.01 36 72

R1114 R1115 5.6 5.6 2W 2W PA INPUT BD PA OUTPUT BD

L1125A L1124A

C1129 L1123 0.1 L1126 L1124B R1101 L1121 15K 50NH L1125B DZ1110 R1110 R1120 C1110 C1121 C1122 1N4735 0.01 0.01 10K 2.7K 0.01 J2 DISC DISC 6.2V ZENER

R1111 10K POT V C1131 C1130 L1122 C1111 0.1 50NH 0.1 0.01 R1112 R1113 5.6 5.6 2W Q1101 2W BLF278 R1116 10K C1112 C1113 T1111P B1 0.01 0.01 _ + C1125 R1119 C1116 R1117 60PF 200 24 27PF B2 3W 3W T11S C1138 C1123 C1124 _ + 0.068 0.01 0.01 T1121 C1114 C1115 B3 0.01 0.01 _ +

R1114 R1115 5.6 5.6 2W 2W PA INPUT BD PA OUTPUT BD

FM500 POWER AMPLIFIER

Reference Drawings 6–21 P10421-9

Illustration 6–14 RF Output Filter (Add 1200 to component designators for schematic reference)

6–22 FM500 User's Manual (455MHz) (195MHz) (176MHz) (252MHz)

C1211 C1202 C1204 C1206 C1208 47PF NP0 R1203 1.35PF 7.1PF 9.3PF 5.13PF R1202 10 *75 RF OUT RF IN

L1202 L1203 L1204 L1205 C1209A L1201 90.5NH 94.1NH 87.5NH 77.9NH 2PF 250NH R1205 C1201 C1203 C1205 C1207 C1209 R1204 C1219 15.4PF 40.9PF 38.9PF 37.7PF 14.1PF 10 * 75 47PF SM

C1201A D1202 C1212 1N6263 10PF C1217 HD1201 47PF NP0 3.5PF 1 Approx. 7V RMS D1201 2 with 200W RF in. 1N6263 R1209 3 1K C1218 R1201 R1206 100 RF MONITOR 47PF SM 1K C1215 R1208 C1216 C1213 .01 C1214 20K .001 .001 R R1207 .01 E F 100K F W L D R1210 10K INDUCTORS I.D. TURNS LENGTH GUAGE RFV

L1201 0.25" 14 0.7" #17 R1211 D1203 C1220 L1202 0.5" 3 0.6" #12 100K 1N6263 .01 L1203 0.5" 3 0.5" #12 1 2 3 4 5 L1204 0.5" 3 0.7" #12

L1205 0.4375" 3 0.6" #12 HD1202 HEADER 5 EXACT COIL LENGTHS ARE FACTORY-SET. NOTES : ______1. ALL RESISTORS ARE IN OHMS, * IF NECESSARY, SELECT R1202 FOR 1/4W, 5% UNLESS OTHERWISE SWR READING OF 1.1 OR BETTER WITH SPECIFIED. 50-OHM LOAD. R1205 = R1202 2. ALL CAPACITORS ARE IN R1202,R1203,C1211,D1202,C1216 MICROFARADS UNLESS ON UNDERSIDE OF CIRCUIT BOARD. OTHERWISE SPECIFIED. 3. C1201-1209A,1217 are circuit board pads. 103209

RF OUTPUT FILTER & REFLECTOMETER

Reference Drawings 6–23

B_L_SHT1_A.DOT REV.A C D A E B F 1 1 J4 1 RF IN J1 OPEN C19 J5 J3 1 1 .01 C1 OPEN R15 2 3 OPEN R1 1 1 R14 SHOWN, ANDDEPICTEDONCOMPONENTMAP. OPEN 4 8 ADDED TOPWB(200922-PWB-DINLOCATION OPEN Vin D1 U2A OPEN OPEN VR1 OPEN 2 2 2 GND L6 1 2 3 Vout OPEN C2 OPEN R2 C23 .01 3 OPEN C18 +5V ARE FORREFERENCEONLY. INCLUDING ASSOCIATEDELECTRONICREPRODUCTIONS CONTROLLED COPY,COPIESOFTHESEDOCUMENTS UNLESS OTHERWISEMARKEDINREDINK BYCMASA OPEN FM30 R8 POWERLEVELCONFIGURATION C4 OPEN R3 OPEN OPEN R4 C24 .01 OPEN R5 3 OHM5W M0 M5 FM500 FM250 FM100 .01 3 2 C3 UNCONTROLLED OPEN D2 3 OHM5W 3 3 1 OPEN R6 C5 22 2.7 OHM5W OPEN R16 51 R17

OPEN 1 C22 IN

2 MHW6342T GND 3 GND XU1 4 N/C 5 VCC R8 6 33uH * L1 N/C DEVICES WITHOUTPERMISSION. FOR THEMANUFACTUREORSALEOFAPPARATUS OR AND ARENOTTOBEREPRODUCED,COPIED ORUSEDASTHEBASIS INTERNATIONAL RADIOANDELECTRONICS CORP. THESE DRAWINGSANDSPECIFICATIONS ARETHEPROPERTYOF 7 6 5 GND 4

8 4 GND 9 OUT 0.01 C6 U2B OPEN 20VDC INPUTAPPLIEDHERE. FOR FM30: 7 T1 UNLESS OTHERWISESPECIFIED: NOTE: R18 0 2. ALLCAPACITORSAREINMICROFARADS. 1. ALLRESISTORSAREINOHMS,1/4WATT+/-5%TOL. E .CN. OPEN L2 361 316 279 264 0.01 C7 5 5 REV R7 OPEN BLF245 P O N M Q1 G OPEN 1/2W R9 51 C16 L7 0.01 OPEN C8 PWB CHG'DTOREV.D PWB CHG'DTOREV.C XU1 WAS200479-TERM-10 PRODUCTION RELEASE S D OPEN C20 L3 REVISION HISTORY FILENAME: DWN CHK CM

PE DESCRIPTION +24VDC 6 6 DISTRIBUTION APPROVALS 4.7K R11 10K R10 OPEN C9 10pF DP DW DW C10 10.4uH L4 10-30-03 08-28-03 10-30-03 36pF C11 6.2V 1N753A D3 FOR FM30:FEEDPOINTFROMPWR.REGULATORPWB. FOR FM500:20V FOR FM100ANDFM250:18V R12 OPEN C21 OPEN TITLE: 36pF SIZE C12 B 23.2uH T L5 IREC 574-262-8900 25166 LEERDRIVEELKHART,IN.46514 INTERNATIONAL RADIOANDELECTRONICSCORP. DWG .NO OPEN RT1 2.7K NTC 5pF C13 FM RFDRIVER 7 7 03-22-05 06-14-04 01-29-04 12-10-03 DATE SCALE :NONE 27pF C14 680pF C15 OPEN R13 DWN DW DW DW DW RF OUT WWW.IREC1.COM Q43310-4 J2 PROJ NO. CHK APPROVALS 0.01 C17 533 CM DW DW DW DW 8 8 DP DP MH DP PE SHEET 1 1 OF REV. P A B C E DWG. NO. Q43310-4 REV. P F P1 Mother Board Voltage Regulator Unreg FM500 CHASSIS WIRING Board FM500 Chassis Wiring 6 C.Donner 2-23-98 5 CROWN BROADCAST Metering HD505 4 Ribbon Cable 3 Board 2 V+ Gnd HD 502 Temp HD701 HD503 1 HD504 J 403 HD561 6 5 4 3 2 1 3 2 1 6 5 4 3 2 1 HD702 Ribbon Ribbon J 602 J 601 Display Board

Reflectometer Feed-Thru

HD1202 2 3 4 5 6 RF Out RF In 1 P803 P802 P801 P807 P806 RF Output P804 Filter & Reflectometer Board P808 P805 Left Power Ribbon Cable Regulator Board Power Amp Interconnect J1 Board Back view

1 37 2 38

Driver input 4 40 5 41 P1 BNC 6 42 8 44 9 45 P3 P3 46 47 Header Socket 12 10 10 13 DC Bus PA 1 DC Input 14 9 9 15 8 8 52 7 7 Driver DC Input 17 53 Inner Fan 18 54 6 6 Temp Sensor 19 55 55 Outer Fans 56 20 4 4 57 Power Transformer 3 22 3 PA 2 DC Input 23 2 2 BLU / WHT DC Bus RED / WHT 24 1 1 25 62 1 2 3 4 5 6

63 P803 P802 P801 P807 P806 P804 120 VAC 57 VAC 28 64 29 65 RED P805 Bridge 31 67 PA RF Output P808 Rectifier 32 68 WHT / BLK + P2 BNC 33 69 Right Power 20 VAC WHT 35 71 36 72 Regulator Board 57 VAC 100 VAC

BLK BLU On BRN / WHT

12.5 VAC BRN Carrier Switch

Off

Brn Wht S1A S1B On Red Blk Red/Wht A D Brn/Wht

* Blk/Wht 120V * 100V Fan Gnd B P5 P4 P1 Red A 240V 220V AC C Gnd Blk Power D Switch * P7 P6 Off AC Input, Fuse, & Filter AC Distribution Board *Jumpered for 120VAC

CHASSIS WIRING 6–26 FM500 User's Manual Illustration 6–16 Receiver Board

Reference Drawings 6–27 Receiver

6–28 FM500 User's Manual 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) 262-8917

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) 262-8917

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 Service at the following number. (866) 262-8917

You may also write to the following address:

International Radio & Electronics Corporation

25166 Leer Drive

Elkhart, Indiana, U.S.A. 46514-5425

7-2 FM600 User’s Manual Three-Year Limited Warranty

North America Only

SUMMARY OF WARRANTY We, Crown Broadcast, a business unit of International Radio and Electronics Company, Inc., 25166 Leer Drive, Elkhart, Indiana 46515–2000 warrant to the ORIGINAL PURCHASER of a NEW Crown Broadcast product, for a period of three (3) years from the date of purchase by the original purchaser (the “warranty period”) that the new Crown Broadcast product is free of defects in materials and workmanship and will meet or exceed all advertised specifications for such a product. This warranty does not extend to any subsequent purchaser or user, and automatically terminates upon sale or other disposition of our product. ITEMS EXCLUDED FROM THIS CROWN BROADCAST We are not responsible for product failure caused by misuse, accident, or neglect. This warranty does not extend to any product on which the serial number has been defaced, altered, or removed. It does not cover damage to loads or any other products or accessories resulting from Crown Broadcast product failure. It does not cover defects or damage caused by use of unauthorized modifications, accessories, parts, or service. WHAT WE WILL DO We will remedy any defect, in material or workmanship (except as excluded), in our sole discretion, by repair, replacement, or refund. If a refund is elected, then you must make the defective or malfunctioning component available to us free and clear of all liens or other encumbrances. The refund will be equal to the actual purchase price, not including interest, insurance, closing costs, and other finance charges less a reasonable depreciation on the product from the date of original purchase. Warranty work can only be performed at our authorized service centers or at our factory. Expenses in remedying the defect will be borne by Crown Broadcast, including two-way surface freight shipping costs within the United States. (Purchaser must bear the expense of shipping the product between any foreign country and the port of entry in the United States and all taxes, duties, and other custom’s fee(s) for such foreign shipments.) HOW TO OBTAIN WARRANTY SERVICE You must notify us of your need for warranty service not later than ninety (90) days after the expiration of the warranty period. We will give you an authorization to return the product for service. All components must be shipped in a factory pack or equivalent which, if needed, may be obtained from us for a nominal charge. Corrective actions will be taken within a reasonable time of the date of receipt of the defective product by us. If the repairs made by us are not satisfactory, notify us immediately. DISCLAIMER OF CONSEQUENTIAL AND INCIDENTAL DAMAGES You are not entitled to recover from us any consequential or incidental damages resulting from any defect in our product. This includes any damage to another product or products resulting from such a defect. WARRANTY ALTERATIONS No person has the authority to enlarge, amend, or modify this warranty. The warranty is not extended by the length of time for which you are deprived of the use of the product. Repairs and replacement parts are provided under the terms of this warranty shall carry only the unexpired portion of this warranty. DESIGN CHANGES We reserve the right to change the design of any product from time to time without notice and with no obligation to make corresponding changes in products previously manufactured. LEGAL REMEDIES OF PURCHASER There is no warranty which extends beyond the terms hereof. This written warranty is given in lieu of any oral or implied warranties not contained herein. We disclaim all implied warranties, including without limitation any warranties of merchantability or fitness for a particular purpose. No action to enforce this warranty shall be commenced later than ninety (90) days after expiration of the warranty period. Crown Broadcast, International and Radio Company, Inc. 25166 Leer Drive, P.O. Box 2000, Elkhart, Indiana 46515–2000

Revised August 2001

Service and Support 7–3 Notes:

7–4 FM500 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 & Electronics Corporation 25166 Leer Drive Elkhart, Indiana, U.S.A. 46514-5425

For units in warranty (within 5 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 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: Telephone: (866) 262-8917 or (866) 262-8972 Fax: ( 866) 262-8909

Name: Company:

Shipping Address:

Phone Number: Fax:

Model: 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: Cash/Check VISA Mastercard Please Quote before servicing

Card Number: Exp. Date: Signature:

Return Shipment Preference if other than UPS Ground: Expedite Shipment Other

ENCLOSE WITH UNIT—DO NOT MAIL SEPARATELY

Service and Support 7-5 Appendix

Transmitter Output Efficiency

FM500 User's Manual Appendix–1 Transmitter efficiency output RF Power Output Efficiency-FM500

PADC Volts PADC Amps RF Power Efficiency 51.3 13.91 550 77%

48.3 13.29 500 78%

45.5 12.74 450 77%

42.7 12.14 400 77%

39.4 11.46 350 78%

36.0 10.68 300 78%

33.0 10.00 250 76%

29.6 9.25 200 73%

25.4 8.28 150 71%

21.1 7.29 100 65%

Power measurements were made at 97.1 MHz. Voltage and current measurements were taken from the unit's built-in metering. The accuracy of the internal metering is better than 2%. Return loss of the RF load was greater than -34dB at test frequency.

Appendix–2 FM500 User's Manual A B C

Glossary

The following pages define terms and abbreviations used throughout this manual.

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 Pins; term used to describe a pin arrangement.

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 destructive to sensitive electronic components.

G–2 FM500 User's Manual exciter (1) A circuit that supplies the initial oscillator used in the driver stage. (2) A transmitter configuration which excludes stereo generation and audio processing. FET 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 Hight Frequency; Frequencies in the 3.0 to 30.0 MHz range.

Highband Frequencies affected by the pre-emphasis.

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 Transis- tor; 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 kilome- ters).

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 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 FM500 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.

VSWR Voltage Standing-Wave Ratio; see "SWR."

Wideband See "broadband."

VCO Voltage-Controlled Oscillator

Glossary G–5 Index

Symbols bias set 5–6 booster 19–kHz transmitter use 1–4 level adjustment 5–3 broadband. See audio: broadband phase adjustment 5–3 bypass A audio processor 2–12, 4–9 C AC. See power: input ALC 3–3, 3–8, 4–8 cables altitude audio input 2–10 operating range 1–8 carrier 4–9, 5–8 amperes automatic turnoff 2–13, 3–8, 5–6, 5– PA DC 3–3, 3–8 10 amplifier frequency 5–8, 5–10 reference drawings 20 carrier switch 3–4, 5–5 RF 4–13 Channel. See frequency bias set 5–6 channel. See frequency antenna 2–9 main 5–10 mismatch 3–3 main into sub 5–10 applications 1–3 sub into main 5–10 audio chassis broadband 3–5 circuit 4–13 distortion 5–9 circuit boards frequency 5–9 audio processor 4–3, 6–4 high 3–5 display 14 input connectors 4–3 metering 10 input level 3–5 motherboard 12 monitor connections 2–12, 4–5 power regulator 18 performance 5–7 RF exciter 8 pre-emphasized 3–5 stereo generator 4–5, 6 processing 3–5, 4–9 voltage regulator 16 wide 3–5 circuits audio processor 3–6 chassis 4–13 adjustments 5–2 display 4–10 board location 4–3 metering 4–8 bypass 2–11, 2–12, 4–9 motherboard 4–9 circuit description 4–3 part numbering 4–2 indicators 3–5 power regulator 4–12 input 3–5 RF exciter 4–6 reference drawings 6–4 stereo generator 4–4 B voltage regulator 4–11 components backup numbering 4–2 transmitter use 1–4 composite bandwidth input 2–11 RF 5–8 input connection 2–11 battery. See power: input output Bessel nulls 5–9

Index–1 adjustment 5–3 temperature 3–8 connectors FCC guidelines 1–8, 5–8, 5–10 audio input 2–10 filter audio monitoring 2–12 RF output 22 composite in 2–11 frequency remote I/O 2–11, 2–13 carrier 5–8, 5–10 RF input 2–9 measurement 5–4 RF output 2–9 pilot 5–8 RF output monitoring 2–9 receiver 2–7 SCA In 2–11 response 5–9 XLR 2–11, 4–3 selection 2–5, 5–4 cooling fan 3–2 receiver 2–7 control 4–9 samples 2–6 coverage area 1–4 synthesizer 5–10 crosstalk 1–7 frequency synthesizer. See RF exciter measurements 5–9 adjustments 5–4 current limit front panel PA 5–5 display modulation calibration 5–6 FSK 1–5, 1–6 D measurement 5–4 DC. See power: input G de-emphasis 2–12, 5–2, 5–7 jumpers 2–12 gain control 3–5 delay gain reduction 4–4 program failure to carrier turnoff 2– gain switches 13, 5–6 input 3–6 dimensions 1–8 DIP H socket 2–10, 4–9 harmonic distortion 4–5 display harmonics 5–8 circuit description 4–10 heatsink 3–8 front panel 3–2, 3–5, 3–7 highband 3–5 modulation calibration 5–6 processing 4–4 display board humidity reference drawings 14 operating range 1–8 distortion 1–7 audio 5–9 I harmonic 4–5 I/O connector 1–2, 2–13 E pinout 2–13 indicators emissions 5–8 audio processor 3–5 exciter. See RF exciter fault 3–8, 4–10 configuration 1–4 highband 3–5 F LED 3–5, 3–7, 4–10 pilot 3–5 fan wideband 3–5, 5–6 control 4–9 input fault audio connections 2–10 indicators 4–10 composite 2–11 input 3–8 fault 3–8 lock 3–8 gain switches 3–5 power 3–8 program servicing 3–8 fault 2–13 SWR 3–8 SCA connection 2–11

Index–2 FM500 User's Manual L pilot indicator 3–5 power labels 1–10 AC supply 4–13 LEDs 3–5, 4–10 AC voltage selection 2–3 line voltage 2–3 amplifier lock reference drawings 20 status 4–7 fault 3–8 lock fault 3–8 input 1–8, 2–3 M FCC guidelines 5–10 output 1–3, 1–7, 5–8 metering 1–2 display 3–7 circuit description 4–8 output filter 4–14 metering board regulator adjustments 5–5 circuit description 4–12 location 4–8, 4–15 RF 3–3, 3–7 reference drawings 10 RF amplifier 4–13 modulation 2–11, 3–5, 5–3, 5–7, 5–8 transformer 4–13 calibration 5–6 power regulator board compensator 2–6 reference drawings 18 display 3–5 power switch 3–4 percentage 3–5, 5–9 pre-emphasis 1–7, 4–4, 5–2, 5–7 monitor curve 2–12 audio 2–12, 4–5 networks 4–3 mono processing operation 2–11, 3–6 audio 2–12, 3–5 motherboard control 3–6 circuit description 4–9 control setting 3–2 reference drawings 12 highband 3–5, 4–4 multimeter 3–7 processor front panel 3–3 audio bypass 2–12 N program failure 2–13, 5–10 program source 2–10, 3–6 networks satellite-fed 1–6 R terrestrial-fed 1–5 noise 1–7, 3–8 receiver measurements 5–9 frequency selection 2–7 option 1–5 O specifications 1–9 reflectometer 4–14, 22 operating environment 1–8, 2–2 regulatory approvals 1–8 options 1–3, 1–4, 1–6 remote control 1–2 output remote I/O power 1–7, 3–7 connector 2–13 display 3–7 pinout 2–13 output filter 4–14 remote operation 2–13 P repair warranty 7–3 part numbering 4–2 parts spares 7–2 performance checklist 5–7 tests 5–10 pilot frequency 5–8

Index–3 R (continued) SWR 3–7 calibrate 5–5 RF fault 3–8 amplifier 4–13 SWR fault 4–9 bias set 5–6 synchronization 4–11 bandwidth 1–8, 5–8 synthesizer. See RF exciter exciter 2–5, 2–11 board location 2–5, 4–6 T circuit description 4–6 reference drawings 8 temperature input 1–5, 2–9 fault 3–8, 4–9 output 1–2, 1–5, 1–7, 3–3, 3–7 operating range 1–8, 5–10 impedance 1–7 PA 3–3, 3–8 output filter 4–14, 22 test point tuning 2–7 voltage 3–8 tests S performance 5–7, 5–10 time-out safety 1–10 program input failure 2–13 satellator transformer 4–13 transmitter use 1–6 translator SCA 1–5 transmitter use 1–5 input connection 2–11 sensitivity V monaural 1–9 stereo 1–9 VCO 4–6 separation voltage stereo 1–7 AC selection 2–3 stereo generator 5–3 voltage regulator 3–8 service adjustments 5–6 warranty 7–3 circuit description 4–11 Service Instructions 7–5 reference drawings 16 specifications voltage selection 2–3 receiver 1–9 voltmeter transmitter 1–7 display 3–8 stand-alone volts transmitter use 1–4 PA DC 3–3, 3–8 stereo VSWR 1–2, 2–9 separation 1–7, 5–9 W stereo generator 1–2, 2–12 adjustments 5–3 Warranty 7–3 board location 4–5 weight 1–8 bypassing 2–11 wideband 3–5, 5–6 circuit description 4–4 reference drawings 6 X subcarrier 5–10 38–kHz 5–10 XLR connectors 2–10 suppression subcarrier 1–7 switches carrier 3–2, 3–4, 5–5 input gain 3–5, 3–6 Normal-Bypass 2–12, 4–9 power 3–4 receiver 2–7 stereo-mono 3–2, 3–6

Index–4 FM500 User's Manual