Crown FM500

ii

Revision ControlRevision 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©2006, Crown Broadcast, a division of International Radio and Electronics, Inc.

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 anyform 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 follow-ing address:

International Radio and Electronics25166 Leer Drive, P.O. Box 2000

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

iii

ContentsContentsContentsContentsContentsSection 1—Getting Acquainted ..................................... 1–11.1 Your Transmitter ............................................................................................... 1–21.2 Applications and Options ................................................................................... 1–31.2.1 Stand-Alone .................................................................................................. 1–41.2.2 Backup .......................................................................................................... 1–41.2.3 Booster ......................................................................................................... 1–41.2.4 Exciter ........................................................................................................... 1–41.2.5 Translator ...................................................................................................... 1–51.2.6 Satellator ...................................................................................................... 1–61.3 Transmitter/Exciter Specifications ..................................................................... 1–71.4 Receiver Specifications ..................................................................................... 1–91.5 Safety Considerations ...................................................................................... 1–101.5.1 Dangers ...................................................................................................... 1–101.5.2 Warnings .................................................................................................... 1–101.5.3 Cautions...................................................................................................... 1–10

Section 2—Installation ............................................... 2–12.1 Operating Environment ...................................................................................... 2–22.2 Remove PA Tray Spacers .................................................................................. 2–22.3 Power Connections ........................................................................................... 2–32.4 Frequency (Channel) Selection .......................................................................... 2–52.4.1 Modulation Compensator .............................................................................. 2–62.4.2 RF Tuning Adjustments ................................................................................. 2–72.5 Receiver Frequency Selection ............................................................................ 2–72.6 RF Connections ................................................................................................. 2–92.7 Audio Input Connections ................................................................................. 2–102.8 SCA Input Connections ................................................................................... 2–112.9 Composite Input Connection ........................................................................... 2–112.10 Audio Monitor Connections ............................................................................. 2–122.11 Pre-emphasis Selection ................................................................................... 2–122.12 Processor Bypass Option ................................................................................ 2–122.13 Program Input Fault Time-out ......................................................................... 2–132.14 Remote I/O Connector ..................................................................................... 2–13

iv

Section 3—Operation ................................................. 3–13.1 Initial Power-up Procedures .............................................................................. 3–23.2 Power Switches................................................................................................. 3–43.2.1 DC Breaker .................................................................................................... 3–43.2.2 Power Switch ................................................................................................ 3–43.2.3 Carrier Switch ............................................................................................... 3–43.3 Front Panel Bar-Dot Displays ............................................................................. 3–53.3.1 Audio Processor Input .................................................................................. 3–53.3.2 Highband and Wideband Display .................................................................. 3–53.3.3 Modulation Display ....................................................................................... 3–53.5 Processing Control ............................................................................................ 3–63.6 Stereo-Mono Switch .......................................................................................... 3–63.4 Input Gain Switches .......................................................................................... 3–63.7 RF Output Control ............................................................................................. 3–73.8 Digital Multimeter .............................................................................................. 3–73.9 Fault Indicators ................................................................................................. 3–8

Section 4—Principles of Operation................................. 4–14.1 Part Numbering ................................................................................................. 4–24.2 Audio Processor Circuit Board .......................................................................... 4–34.3 Stereo Generator Circuit Board .......................................................................... 4–44.4 RF Exciter Circuit Board .................................................................................... 4–64.5 Metering Circuit Board ...................................................................................... 4–84.6 Motherboard ..................................................................................................... 4–94.7 Display Circuit Board ....................................................................................... 4–104.8 Voltage Regulator Circuit Board ...................................................................... 4–114.9 Power Regulator Circuit Boards ...................................................................... 4–124.10 RF Driver ......................................................................................................... 4–124.11 RF Amplifier .................................................................................................... 4–134.12 Chassis ........................................................................................................... 4–134.13 RF Output Filter & Reflectometer ..................................................................... 4–144.15 Receiver Circuit Board Option ......................................................................... 4–14

v

Section 5—Adjustments and Tests ................................. 5–15.1 Audio Processor Adjustments ........................................................................... 5–25.1.1 Pre-Emphasis Selection ................................................................................ 5–25.1.2 Pre-Emphasis Fine Adjustment ..................................................................... 5–25.2 Stereo Generator Adjustments .......................................................................... 5–35.2.1 Separation .................................................................................................... 5–35.2.2 Composite Output ......................................................................................... 5–35.2.3 19 kHz Level ................................................................................................. 5–35.2.4 19 kHz Phase ................................................................................................ 5–35.3 Frequency Synthesizer Adjustments .................................................................. 5–45.3.1 Frequency (Channel) Selection ...................................................................... 5–45.3.2 Modulation Compensator .............................................................................. 5–45.3.3 Frequency Measurement and Adjustment ..................................................... 5–45.3.4 FSK Balance Control ..................................................................................... 5–45.4 Metering Board Adjustments ............................................................................. 5–55.4.1 Power Calibrate ............................................................................................. 5–55.4.2 Power Set ..................................................................................................... 5–55.4.3 SWR Calibrate ............................................................................................... 5–55.4.4 PA Current Limit ........................................................................................... 5–55.5 Motherboard Adjustments ................................................................................. 5–65.6 Display Modulation Calibration .......................................................................... 5–65.7 Voltage Regulator Adjustments ......................................................................... 5–65.8 Bias Set (RF Power Amplifier) ........................................................................... 5–65.9 Performance Verification ................................................................................... 5–75.9.1 Audio Proof-of-Performance Measurements ................................................. 5–75.9.2 De-emphasis Input Network .......................................................................... 5–75.10 Carrier Frequency .............................................................................................. 5–85.11 Output Power .................................................................................................... 5–85.12 RF Bandwidth and RF Harmonics ...................................................................... 5–85.13 Pilot Frequency ................................................................................................. 5–85.14 Audio Frequency Response ............................................................................... 5–95.15 Audio Distortion ................................................................................................ 5–95.16 Modulation Percentage ...................................................................................... 5–95.17 FM and AM Noise .............................................................................................. 5–95.18 Stereo Separation .............................................................................................. 5–95.19 Crosstalk ........................................................................................................... 5–95.19.1 Main Channel Into Sub .............................................................................. 5–105.19.2 Sub Channel Into Main .............................................................................. 5–105.20 38 kHz Subcarrier Suppression ....................................................................... 5–105.21 Additional Checks ............................................................................................ 5–10

Section 6—Reference Drawings .................................... 6–16.1 Views ................................................................................................................ 6–26.2 Board Layouts and Schematics ......................................................................... 6–4

Section 7—Service and Support .................................... 7–17.1 Service .............................................................................................................. 7–27.2 24–Hour Support .............................................................................................. 7–27.3 Spare Parts ....................................................................................................... 7–2

Appendix ................................................................ A–1

Glossary ................................................................. G–1

Index................................................................ Index–1

1–1Getting Acquainted

Section 1—Getting Acquainted

This section provides a general description of the FM500 trans-mitter and introduces you to safety conventions used within thisdocument. Review this material before installing or operatingthe transmitter.

IINFORMATION

1–2 FM500 User's Manual

I1.1 Your TransmitterThe FM500 is a member of a family of FM stereo broadcast transmitters. Crowntransmitters are known for their modularity, ease-of-use, and reliability.

The modularity is most apparent in the standard transmitter configuration whichincorporates audio processing, stereo generation, and RF amplification withoutcompromised signal quality. A single Crown transmitter can replace several piecesof equipment in a traditional system.

Ease-of-use is apparent in the user-friendly front panel interface and in the instal-lation procedure. Simply select your operating frequency (using four rotaryswitches), add an audio source, attach an antenna, connect AC power, and you'reready to broadcast. Of course, the FM series of transmitters also feature moresophisticated inputs and monitoring connections if needed.

Reliability is a Crown tradition. The first Crown transmitters were designed forrigors of worldwide and potentially portable use. The modular design, qualitycomponents, engineering approach, and high production standards ensure stableperformance.

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 multi-meter display and status indicators. Automatic control circuitry provides protec-tion for high VSWR as well as high current, voltage, and temperature conditions.

Illustration 1–1 FM500 Stereo Broadcast Transmitter

FM500FM BROADCAST TRANSMITTER

®

Power

CarrierModulationFault

Stereo

Mono RF OutputProcessingInput Gain

Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot


1.2 Applications and OptionsCrown transmitters are designed for versatility in applications. They have been usedas stand-alone and backup transmitters and in booster, translator, and satellatorapplications. The following discussion describes these applications further.

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

The number portion of each name represents the maximum RF output power. TheFM500, 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 themanual except where specified. In this configuration, the product includes thefollowing modules (functions):

audio processor

stereo generator

RF exciter

metering

low-pass filter

Illustration 1–2 Standard (Transmitter) Configuration

RF Exciter

Metering

Low-pass FilterStereo Generator

Audio Processor


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot


I1.2.1 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), anantenna, and AC power, the transmitter becomes a complete FM stereo broadcaststation, capable of serving a community.

As stand-alone transmitters, Crown units often replace multiple pieces of equip-ment in a traditional setup (exciter, audio processor, RF amplifier).

1.2.2 Backup

In the standard configuration, Crown transmitters are also used in backup applica-tions. Should your primary transmitter become disabled, you can continue tobroadcast while repairs take place. In addition, the FM transmitters can replacedisabled portions of your existing system including the exciter, audio processor, oramplifier. Transfer switches on each side of the existing and backup transmittersmake the change-over possible with minimal downtime.

1.2.3 Booster

Also in the standard configuration, Crown transmitters have been used as boostertransmitters. Booster applications typically involve certain geographic factorswhich prevent your system from broadcasting to the full coverage area allowable.For example, a mountain range might block your signal to a portion of yourcoverage area. Careful placement of a Crown transmitter, operating on the samefrequency 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 optionalconfigurations to meet a variety of needs.

An "E" suffix, as in the FM500E, for example, represents an exciter-only configura-tion. In this configuration, the audio processor and stereo generator are notincluded. 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 areperforming satisfactorily and you want to maximize your investment in presentequipment.


1.2.5 Translator

A receiver configuration (FM500R, for example) takes an exciter configuration andadds receiver circuitry as well. This added feature makes the FM500 ideal fortranslator service in terrestrial-fed networks. These networks represent a popularand effective way to increase your broadcasting coverage. Translators, acting asrepeater emitters, are necessary links in this chain of events.

Traditionally, network engineers have relied on multiple steps and multiple piecesof equipment to accomplish the task. Others have integrated the translatorfunction (receiver and exciter) to feed an amplifier. Crown, on the other hand,starts with an integrated transmitter and adds a solid-state Receiver Module toform the ideal translator.

Illustration 1–3 Crown's Integrated Translator

This option enables RF in and RF out on any of Crown’s FM series of transmitters.In addition, the module supplies a composite output to the RF exciter portion ofthe transmitter. From here, the signal is brought to full power by the built-inpower amplifier for retransmission. The Receiver Module has been specificallydesigned to handle SCA channel output up to 100 kHz for audio and high-speeddata.

FSK ID programming is built-in to ensure compliance with FCC regulationsregarding the on-air identification of translators. Simply specify the call sign ofthe repeater station when ordering. Should you need to change the location of thetranslator, replacement FSK chips are available. The Receiver Module optionshould be ordered at the time of initial transmitter purchase. However, an optionkit is available for field converting existing Crown units.

StereoGenerator

RF INReceiver Module(option)

RF OutLow-pass Filter

Metering

RF Exciter


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot


I1.2.6 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 fre-quency 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 FSKIDer does the rest—shifting the frequency to comply with FCC requirements andin a manner that is unnoticeable to the listener. The FSK IDer module should beordered at the time you order your transmitter but is available separately (factoryprogrammed for your installation).

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

Illustration 1–4 Transmitter with FSK IDer Option

StereoGenerator

AudioProcessor Metering

FSK IDer(option)

RF OutLow-pass Filter

RF Exciter


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot


1.3 Transmitter/Exciter Specifications

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

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

RF Output Impedance 50 Ω

Frequency Stability Meets FCC specifications from0-50 degrees C

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

Audio Input Level Selectable for –10 dBm to +10 dBm for75 kHz deviation at 400 Hz

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

Audio Response Conforms to 75 µsec pre-emphasis curveas 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


IAM 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


1.4 Receiver SpecificationsMonaural Sensitivity (demodulated, de-emphasized)

3.5 µV for signal-to-noise > 50 dB


Stereo Sensitivity (19–kHz pilot frequency added)


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


I

Illustration 1–5 Sample Hazard Alert

Severe shock hazard!

Turn power off andwait approximately 1minute for capacitorsto discharge beforehandling them.

WARNINGType of Hazard

Pictorial Indicationof Hazard

Explanation ofHazard

1.5 Safety ConsiderationsCrown Broadcast assumes the responsibility for providing you a safe product andsafety guidelines during its use. “Safety” means protection to all individuals whoinstall, operate, and service the transmitter as well as protection of the transmitteritself. To promote safety, we use standard hazard alert labeling on the product andin this manual. Follow the associated guidelines to avoid potential hazard.

1.5.1 DangersDANGER represents the most severe hazard alert. Extreme bodily harm or deathwill occur if DANGER guidelines are not followed.

1.5.2 WarningsWARNING represents hazards which could result in severe injury or death.

1.5.3 CautionsCAUTION indicates potential personal injury or equipment or property damage ifthe associated guidelines are not followed. Particular cautions in this text alsoindicate unauthorized radio-frequency operation.

2–1Installation

Section 2—Installation

This section provides important guidelines for installing your trans-mitter. Review this information carefully for proper installation.

®


2.1 Operating Environment

You can install the FM transmitter in a standard component rack or on a suitablesurface 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 forventilation. If you set the transmitter on a flat surface, install spacers on thebottom cover plate. If you install the transmitter in a rack, provide adequateclearance above and below. Do not locate the transmitter directly above a hot pieceof equipment.

2.2 Remove PA Tray SpacersThe Crown FM 500 is shipped with spacers between the PA tray and the transmitterback panel. The spacers prevent damage to internal contacts during shipping.Remove and save the spacers and screws before installing the FM500.

Possible equipment damage!

Before operating the transmitter forthe first time, check for the proper ACline voltage setting and frequencyselection as described in sections 2.3and 2.4.

CAUTION

1. Remove screws and spacers from five locations.

2. Firmly push the PA tray into the FM 500 until the PA tray panel touches theback panel.

3. Locate the bag labeled 500 Hardware. Install four #8 screws and washers andone number #6 screw and washer. See photo for locations.

#6

#8

#8

Illustration 2-1 FM 500 PA Tray Mounting Screws

2–3Installation

115V230V

Illustration 2–3Removing the Voltage Selection (red) Assembly

Illustration 2–2Opening the Power Connector Cover

115V

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 anychanges. To operate the FM500 at 100, 220, or 240 volts, a few changes arenecessary.

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 bladescrewdriver. 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 installedfuses 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 upin the window. Close the assembly window.


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

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 largetransformer 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 ampfuses for 100 or 120 volt operation.

front of transmitter

PowerDistributionBoard

2–5Installation

2.4 Frequency (Channel) Selection

You may select an operating frequency of 87 to 108 MHz in the FM broadcast bandwith 100 kHz channel spacing (10 kHz spacing is optional with the addition of afifth 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 switcheswhich will be used to change the setting. See Illustrations 2–5 and 2–6.

Illustration 2–6 RF Exciter Board Frequency Selector Switches

Illustration 2–5 Top Cover Removed

Frequency SelectionRotary Switches

ModulationTrim-pot

RF Exciter


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot

MEGAHERTZ .1 .01


3. Use small flat blade screwdriver or another suitable device to rotate theswitches to the desired setting. (The selected number will appear directlyabove the white indicator dot on each switch.) See examples of selectedfrequencies in the illustration below.

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

2.4.1 Modulation Compensator

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

Illustration 2–7 Two Sample Frequency Selections

These compensator settings are approximate. Each mark on the potentiometerrepresents about 1.8% modulation compensation. For more exact settings, refer tosection 5.2.2.

Illustration 2–8 Modulation Compensator Settings

= 88.1 MHz

= 107.9 MHz

Modulation Compensation Pot Setting

0

10

20

30

40

50

60

70

80

90

75 80 85 90 95 100 105 110

Frequency (MHz)

2–7Installation

2.4.2 RF Tuning Adjustments

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

2.5 Receiver Frequency SelectionIf you have a transmitter equipped with the receiver option, you will need to setthe 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 desiredincoming frequency.

3. After setting the frequency, return to section 2.3.1 to set the modulationcompensator.

Illustration 2–8 Receiver Module Switches

StereoGenerator

Frequency SelectionSwitches SW1 & SW2 RF IN

ReceiverModule RF Exciter


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot


Table 2–1 Receiver Frequency Selection

Frequency SW1 SW2

87.9 0 088.0 8 088.1 0 188.2 8 188.3 0 288.4 8 288.5 0 388.6 8 388.7 0 488.8 8 488.9 0 5

89.0 8 589.1 0 689.2 8 689.3 0 789.4 8 789.5 0 889.6 8 889.7 0 989.8 8 989.9 0 A

90.0 8 A90.1 0 B90.2 8 B90.3 0 C90.4 8 C90.5 0 D90.6 8 D90.7 0 E90.8 8 E90.9 0 F

91.0 8 F91.1 1 091.2 9 091.3 1 191.4 9 191.5 1 291.6 9 291.7 1 391.8 9 391.9 1 4

92.0 9 492.1 1 592.2 9 592.3 1 692.4 9 692.5 1 792.6 9 792.7 1 892.8 9 892.9 1 9

Frequency SW1 SW2

98.0 B 298.1 3 398.2 B 398.3 3 498.4 B 498.5 3 598.6 B 598.7 3 698.8 B 698.9 3 7

99.0 B 799.1 3 899.2 B 899.3 3 999.4 B 999.5 3 A99.6 B A99.7 3 B99.8 B B99.9 3 C

100.0 B C100.1 3 D100.2 B D100.3 3 E100.4 B E100.5 3 F100.6 B F100.7 4 0100.8 C 0100.9 4 1

101.0 C 1101.1 4 2101.2 C 2101.3 4 3101.4 C 3101.5 4 4101.6 C 4101.7 4 5101.8 C 5101.9 4 6

102.0 C 6102.1 4 7102.2 C 7102.3 4 8102.4 C 8102.5 4 9102.6 C 9102.7 4 A102.8 C A102.9 4 B

Frequency SW1 SW2

93.0 9 993.1 1 A93.2 9 A93.3 1 B93.4 9 B93.5 1 C93.6 9 C93.7 1 D93.8 9 D93.9 1 E

94.0 9 E94.1 1 F94.2 9 F94.3 2 094.4 A 094.5 2 194.6 A 194.7 2 294.8 A 294.9 2 3

95.0 A 395.1 2 495.2 A 495.3 2 595.4 A 595.5 2 695.6 A 695.7 2 795.8 A 795.9 2 8

96.0 A 896.1 2 996.2 A 996.3 2 A96.4 A A96.5 2 B96.6 A B96.7 2 C96.8 A C96.9 2 D

97.0 A D97.1 2 E97.2 A E97.3 2 F97.4 A F97.5 3 097.6 B 097.7 3 197.8 B 197.9 3 2

Frequency SW1 SW2

103.0 C B103.1 4 C103.2 C C103.3 4 D103.4 C D103.5 4 E103.6 C E103.7 4 F103.8 C F103.9 5 0

104.0 D 0104.1 5 1104.2 D 1104.3 5 2104.4 D 2104.5 5 3104.6 D 3104.7 5 4104.8 D 4104.9 5 5

105.0 D 5105.1 5 6105.2 D 6105.3 5 7105.4 D 7105.5 5 8105.6 D 8105.7 5 9105.8 D 9105.9 5 A

106.0 D A106.1 5 B106.2 D B106.3 5 C106.4 D C106.5 5 D106.6 D D106.7 5 E106.8 D E106.9 5 F

107.0 D F107.1 6 0107.2 E 0107.3 6 1107.4 E 1107.5 6 2107.6 E 2107.7 6 3107.8 E 3107.9 6 4

108.0 E 4

2–9Installation

Severe shock hazard!

Do not touch the innerportion of the RFoutput connectorwhen transmitterpower is on.

WARNING

Illustration 2–10 RF Connections

2.6 RF Connections

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

The RF monitor is intended primarily for a modulation monitor connection.Information gained through this connection can supplement that which isavailable on the transmitter front panel displays.

If your transmitter is equipped with the receiver option, connect the incoming RFto the RF IN connector.

115V

RF OutputConnector

RF OutputMonitor

RFInput Connector(receiver option only)


2.7 Audio Input Connections

Attach audio inputs to the Left and Right XLR connectors on the rear panel. (TheLeft channel audio is used on Mono.) Pin 1 of the XLR connector goes to chassisground. Pins 2 and 3 represent a balanced differential input with an impedance ofabout 50 kΩ. They may be connected to balanced or unbalanced left and rightprogram sources.

The audio input cables should be shielded pairs, whether the source is balanced orunbalanced. For an unbalanced program source, one line (preferably the oneconnecting to pin 3) should be grounded to the shield at the source. Audio willthen connect to the line going to pin 2.

Illustration 2-10 XLR Audio Input Connectors

By bringing the audio return line back to the program source, the balanceddifferential 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 goodpractice for any distance.

If the program source requires a 600 Ω termination, install resistors on the 8–pinDIP socket on the motherboard (socket A501 located between the XLRconnectors). See the motherboard schematic, on page 6–13.

SCA IN COMPOSITE IN MONITOR

R L

2 3

REMOTE I/O

RIGHT LEFT/MONO

1

AudioInputs

2–11Installation


R L

2 3

REMOTE I/O

RIGHT LEFT/MONO

1

SCA Inputs(BNC) Connectors

Illustration 2–12 SCA Input Connectors

2.8 SCA Input ConnectionsYou can connect external SCA generators to the SCA In connectors (BNC-type) onthe rear panel. The inputs are intended for the 60 kHz to 99 kHz range, but alower frequency may be used if the transmitter is operated in Mono mode. (The 23to 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.

2.9 Composite Input ConnectionTo 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 Inputsection of the transmitter. This will feed composite stereo (or mono audio) directlyto the RF exciter. In the "T" version, this will bypass the internal audio processorand stereo generator. See Section 2.12 on the next page for caution in using thebypass 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.


2.10 Audio Monitor ConnectionsProcessed, de-emphasized samples of the left and right audio inputs to the stereogenerator are available at the Monitor jacks on the rear panel. The signals aresuitable for feeding a studio monitor and for doing audio testing. De-emphasis isnormally set for 75 µsec; set to 50 µsec by moving jumpers, JP203 and JP204, onthe Stereo Generator board.

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

2.12 Processor Bypass OptionYou may bypass the audio processor in order to feed the left and right (pre-emphasized) audio directly to the stereo generator. The Normal-Bypass slideswitch is near the left-rear corner of the motherboard. If the audio source isalready processed and you do not desire further processing, use the Normal modebut turn the Processing control (on the front panel) to “0.” (See also section 3.5.)

In the BYPASS position, the pre-emphasis circuits and the filters that protect thepilot and stereo subcarrier are bypassed. As a result, the occupied bandwidthspecifications of the transmitter could be compromised. The 15–Hz high-passfilters are also bypassed which may mean that modulation with frequenciesbelow 10 Hz could cause the frequency synthesizer to unlock.

CAUTION

Illustration 2–13 Composite In and Audio Monitor Connections


R L

2 3

REMOTE I/O

RIGHT LEFT/MONO

1

Audio Monitor(RCA) Jacks

Composite Input(BNC) Connector

2–13Installation

2.13 Program Input Fault Time-outYou 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 programfailure and carrier turn-off is set by a jumper (JP701) on the voltage regulatorboard (see Illustration 6–4 for board location). Jumper pins 1 and 2 (the two pinsclosest to the edge of the board) for a delay of approximately 30 seconds; pins 3 and4 for a 2–minute delay; pins 5 and 6 for a 4–minute delay, and pins 7 and 8 for an8–minute delay.

2.14 Remote I/O ConnectorRemote control and remote metering of the transmitter is made possible through a15–pin, D-sub connector on the rear panel. (No connections are required fornormal operation.)

Illustration 2–14 Remote I/O Connector

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


R L

2 3

REMOTE I/O

RIGHT LEFT/MONO

1

Remote I/O


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 carrierfrequency approximately 7.5 kHz. Connect to opencollector or relay contacts of user-supplied FSK keyer.)

5 /Auto Carrier Off (Pull low to enable automatic turnoffof 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 stereogenerator and enable External Composite Input.)

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

b) For transmitters equipped with tuner option, this pinbecomes the right audio output for an 8–ohm monitorspeaker. 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 isactivated.)

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

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

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

Table 2–3 Remote I/O Connections

1

15

8

9

3–1Operation

Section 3—Operation

This section provides general operating parameters of yourtransmitter and a detailed description of its front panel display.


Possible equipment damage!

Before operating the transmitter forthe first time, check for the proper ACline voltage setting and frequencyselection as described in sections 2.3and 2.4.

CAUTION

1. Turn on the main power switch.

Illustration 3–1 Front Panel Power Switches

3.1 Initial Power-up Procedures

These steps summarize the operating procedures you should use for the initialoperation of the transmitter. More detailed information follows.

2. Verify the following:

a. The bottom cooling fans runs continuously.

b. The Lock Fault indicator flashes for approximately 5 seconds, then goesoff.

4. Set the Input Gain switches for mid-scale wideband gain reduction on anaverage 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.


Power


Stereo

Mono RF Output

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot

Power Switch

Carrier Switch

3–3Operation

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 anantenna 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 tempera-ture). 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 thecarrier 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 indicatorsand switches.


3.2 Power Switches

3.2.1 DC Breaker

The DC breaker, on the rear panel, must be on (up) for transmitter operation, evenwhen using AC power. Electrically, the DC breaker is located immediately afterdiodes 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 batterypower input.

3.2.3 Carrier Switch

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

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

Illustration 3–2 Front Panel Power Switches


Power


Stereo

Mono RF Output

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot

Power Switch

Carrier Switch

3–5Operation

3.3 Front Panel Bar-Dot Displays

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

3.3.1 Audio Processor Input

Two vertical, moving-dot displays for the left and right channels indicate the relativeaudio levels, in 3 dB steps, at the input of the audio processor. Under normal operat-ing conditions, the left and right Audio Processor indicators will be active, indicatingthe 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 controlfor broadband (Wide) and pre-emphasized (High) audio. These indicators are disabledif the receiver module option is installed.

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

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

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

High-frequency program content affects the activity of the Highband indicator. With75–µsec pre-emphasis, Highband processing begins at about 2 kHz and increases as theaudio frequency increases. Some programs, especially speech, may show no activitywhile 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 percent-age. 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 trans-mitter is in the stereo mode.

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


3.4 Input Gain Switches

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

Table 3–1 Input Gain Switches

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

3.5 Processing Control

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

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

3.6 Stereo-Mono Switch

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

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

3–7Operation

3.7 RF Output Control

Set this control for the desired output power level. Preferably, set the power with anexternal RF wattmeter connected in the coaxial line to the antenna. You may also usethe RF power reading on the digital multimeter.

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

Illustration 3–3 Digital Multimeter

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

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


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot

Digital Multimeter Multimeter Functions Multimeter Push-buttons

CAUTIONPossible equipment damage!

Operation below 100 watts can causeoscillations and other problems thatcould damage the transmitter.

3.8 Digital Multimeter

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


ALC—DC gain control bias used to regulate PA supply voltage. With the PA powersupply at full output voltage, ALC will read about 6.0 volts. When the RF output isbeing regulated by the RF power control circuit, this voltage will be reduced, typi-cally reading 4 to 5.5 volts. The ALC voltage will be reduced during PA DCovercurrent, 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. Forbattery 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 mother-board. A test lead connected to this point can be used for making voltage measure-ments in the transmitter. The test point is intended as a servicing aid; an alternativeto an external test meter. Remember that the accuracy is only as good as the refer-ence voltage used by the metering circuit. Servicing a fault affected by the referenceaffects 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 RFpower.

Lock—Frequency synthesizer phase-lock loop is unlocked. This indicator normallyblinks 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 poweramplifier.

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

PA DC—Power supply current for the RF power output amplifier is at the presetlimit. ALC voltage has been reduced, reducing the PA supply voltage to hold supplycurrent 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 supplyvoltage to prevent a further increase in temperature. By 85° C (185° F), the PA willbe fully cut off.

4–1Principles of Operation

Section 4—Principles of Operation

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

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4.1 Part Numbering

As this section refers to individual components, you should be familiar with thepart numbering scheme used. Although parts on the various circuit boards andcircuit board drawings may be marked with identical reference numbers, eachcomponent 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 partnumbers (as shown on the schematic). To find the full number, refer to the chartbelow. R401, for instance, is marked “R1” on the Metering board and on itscomponent 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 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 usefulto you during this discussion.

Illustration 4–2 Audio Processor Board

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

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

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

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 totake 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), formthird-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 atpin 13 and the DC voltage difference between pins 7 and 9. At full gain (no gainreduction) this difference will be 10 volts DC.

Audio Processor


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot




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When either the positive or negative peaks of the output of U5 (U6) exceeds thegain-reduction threshold, U13A generates DC bias, producing broadband gainreduction. Q5 is a precision-matched transistor pair. Q5 and U13B form a logconverter, so that a given voltage change produces a given change in gain controldB of U5 (U6). The log conversion ensures uniform level-processing characteristicswell 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 normalprogram level. The amount of short-term expansion and gain reduction iscontrolled 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 µsecondpre-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 headerJP1. Use trim pot R29 (R65) to make fine adjustments to the pre-emphasis. (Seesection 5.1.)

For highband processing, the peak output of U10B is detected and gain-reductionbias 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 andU18. This same reference voltage is used by the stereo generator, metering, anddisplay 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 signalfrom left and right-channel audio inputs. The component side of the board ismostly a ground plane. Once again, the eighth-order, 15.2 kHz, elliptical, low-passfilters (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 and38 kHz subcarriers are digitally synthesized. U207F is a buffer. The 7.6 MHz isdivided 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 kHzsine wave—a scheme described in the CMOS Cookbook by Don Lancaster (HowardW. Sams &. Co., Inc., Indianapolis, IN, 1978).

With the resistor ratios used, the synthesized sine wave has very little harmonicenergy 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,


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 dBdown—THD of less than 0.05%.

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

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

Analog switch U205, at the input of U206B, provides switching of left and rightaudio for stereo and mono modes. In the mono mode, right channel audio isdisabled, 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-emphasisnetwork. Processed, de-emphasized (75 µsec) samples of the stereo generatorinput signals are used for a studio monitor and for audio testing. Option jumpersJP203 (JP204) allow you to select 50 µsec.

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

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

Stereo Generator


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot




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4.4 RF Exciter Circuit BoardThis board is also known as the Frequency Synthesizer board. The entirecomponent side of the board is a ground plane. Rotary switches along the frontedge of the board establish the operating frequency. The VCO (voltage-controlledoscillator) circuitry is inside a shielded cover.

Illustration 6–7 and accompanying schematic can be used as reference in thisdiscussion. The following theory may apply to previous versions of the exciterboard, but it is typical of the operation of the current board which has the latesttechnological 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. U7Aand U7B form an active filter to supply clean DC to the drain of Q71. They alsoserve as a common-base RF amplifier for Q71. A71 and A1 are hybrid RF amplifiersto provide buffering and gain.

A sample of the RF from the VCO goes to the input of A2. A2 amplifies the signaland 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 frequencymeasurements. (See sections 5.2 and 5.3.)

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

Illustration 4–4 RF Exciter Board

RF Exciter


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot


U6 is programmed with the four or five rotary switches. The binary output of the0.1 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 ofphase with that appearing on the error voltage is introduced by U5A, allowing forgreater 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-lawcapacitance vs DC voltage curve, giving a straight-line frequency vs voltage curvein 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 thefrequencies of the 10.24 MHz crystal reference and the VCO. With keying, diodesD9 and D10, are reverse biased, increasing the crystal reference frequency. At thesame time, current through R72 increases the VCO frequency. See section 5.3.4.




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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 digitalpanel meter, voltages for remote metering, fan control, and drive for thefront-panel fault indicators.


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 currentto voltage used for metering and control. A voltage divider from the PAV line isused for DC voltage metering.

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

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

U404C, U404A, U403A, and U404D are level sensors for RF power, reflected RFpower, PA temperature, and external PA current, respectively. When either ofthese 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 supplyvoltage.

Illustration 4–5 Metering Board

Metering


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot


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 fedfrom a voltage proportional to the forward-minus-reflected RF voltage, whileforward-plus-reflected is fed to the digital panel meter input. The panel meterprovides the divide function.

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

The output voltage of U403D goes positive when the temperature exceeds about 35degrees 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 SWRautomatically switches to a calibrate-check mode. U406C provides a voltage thatsimulates 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 MotherboardThe motherboard is the large board in the upper chassis interconnecting the audioprocessor, stereo generator, RF exciter, and metering boards. The motherboardeliminates the need for a wiring harness, and provides input/output filtering, testpoints, 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 audioprocessor, connecting the left and right audio inputs directly to the inputs of thestereo generator.

In the BYPASS position, the pre-emphasis circuits and the filters that protect thepilot and stereo subcarrier are bypassed. As a result, the occupied bandwidthspecifications of the transmitter could be compromised. The 15–Hz high-passfilters are also bypassed which may mean that modulation with frequenciesbelow 10 Hz could cause the frequency synthesizer to unlock.

CAUTION

If the audio source is already processed, and further processing is not desired, usethe Normal mode instead of Bypass and turn the Processing control on the frontpanel 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 DIPsocket, A501, located between the XLR input connectors. See Illustration 6–9 andaccompanying schematic for the socket pin-out.




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4.7 Display Circuit Board

The front-panel LEDs, the numeric display, the slide switches, and the processingand RF level controls are mounted on the display circuit board. To access thecomponent side of the board, remove the front panel by removing 12 screws. Theboard contains circuits for the digital panel meter, modulation peak detector, andLED display drivers, as well as indicators and switches mentioned above.


Left and right audio from input stages of the audio processor board (just after theInput Gain attenuator) go to the L VU and R VU input on the display board. Peakrectifiers U601A and U601B drive the left and right Audio Input displays. The LEDdriver gives a 3 dB per step display. The lowest step of the display driver is notused; rather a red LOW indicator lights when audio is below the level of the secondstep. Transistors Q601 and Q602 divert current from the LOW LEDs when anyother LED of the display is lit.

Resolution of the linear displays, High Band, Wide Band, and Modulation, has beenimproved using dither enhancement. With dither, the brightness of the LED iscontrolled by proximity of the input voltage relative to its voltage threshold. Theeffect is a smooth transition from step to step as input voltage is changed. U606A,U606B, and associated components comprise the dither generator. Dither outputis 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 ofthe multimeter menu. Signals from the push buttons are conditioned by U609Aand U609B. U610 is an up/down counter. Binary input to U611 from U610 selectsa green menu indicator light, and lights the appropriate decimal point on thenumeric 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 digitalmultimeter IC U612. They originate from analog data selectors on the ALC/metering board.


4.8 Voltage Regulator Circuit Board

The voltage regulator board is the longer of two boards mounted under the chassistoward 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 carriercontrol circuits.


U703E and U703F convert a 38 kHz sine wave from the stereo generator into asynchronization pulse. In the transmitter, synchronization is not used, thus D709is omitted.

U704 and U705 form a 24 volt switching regulator running at about 35 kHz. U704is used as a pulse-width modulator; U705 is a high-side driver for MOSFET switchQ701. Supply voltage for the two IC’s (approximately 15.5 volts) comes from linearregulator DZ702/Q705. Bootstrap voltage, provided by D710 and C714, allows thegate voltage of Q701 to swing about 15 volts above the source when Q701 is turnedon. Current through the FET is sensed by R738 and R738A. If the voltagebetween pin 5 and 6 of U705 exceeds 0.23 volts on a current fault, drive to Q701 isturned off. Turn-off happens cycle by cycle. The speed of the turn-off is set byC713.

U706 is a switching regulator for both +12 volts and –12 volts. It runs at about 52kHz. Energy for –12 volts is taken from inductor L702 during the off portion ofthe switching cycle. The –12 volts tracks the +12 volts within a few tenths of avolt. 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 tothe RF driver, when the Carrier switch is on.

The program detection circuit is made up of U701 and U702. U701A and U701Dand associated circuitry discriminate between normal program material and whitenoise (such as might be present from a studio-transmitter link during programfailure) or silence. U701A and surrounding components form a band-pass filterwith a Q of 3 tuned to about 5 kHz. U701D is a first-order low-pass filter. Red andgreen LEDs on the board indicate the presence or absence of program determinedby the balance of the detected signals from the two filters. U702 and U701C form acount-down timer. The time between a program fault and shutdown is selected byjumpering pins on header JP701. For times, see section 5.7. The times areproportional to the value of R721 (that is, times can be doubled by doubling thevalue of R721).




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4.9 Power Regulator Circuit Boards

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


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

U801 and U802 form a switching regulator running at about 35 kHz. U801 is usedas 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 byzener diode DZ801. Bootstrap voltage provided by D802 and C809 allows the gatevoltage 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 5to 6 of U802 exceeds 0.23 volts on a current fault, drive to Q801 is turned off. Thishappens 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 throughmetering shunt, R819, into a current source at the collector of Q803. Fortymillivolts is developed across R819 for each amp of supply current (.04 ohms x 1amp). Q803 is biased by U803 to produce the same voltage across R816. Thecollector current of Q803 is the same (minus base current) as that flowing throughR822 resulting in 40 microamperes per amp of shunt current. R405 on themetering board converts Q803 collector current to 0.1 volt per amp of shuntcurrent (.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 RFAmplifier/Combiner sub chassis. The driver amplifies the approximate 20milliwatts from the frequency synthesizer to about 15 watts to drive the RF poweramplifiers. A CA2832 hybrid, high-gain, wideband amplifier, operating at about 20volts, provides about one watt of drive to a single MRF137 MOSFET amplifier. TheMRF137 stage operates from a supply voltage of approximately 15 to 16 volts.

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


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 tothe back panel with six screws. RF power, DC power, and control voltages enter thePA assembly through a 72–pin edge connector that it slides into at the front of thechassis.

The amplifier is built around two Phillips BLF278, dual-power MOSFETs rated for50 volts DC and a maximum power of about 300 watts. When biased for class B, thetransistor 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-turnprimary 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 atwo-turn secondary underneath. Inductors L1121 and L1122 provide power linefiltering.

The amplifiers are surrounded by a 50 Ω impedance, input/output combiner boardwhich takes the 15 watts input and divides it equally to each power amp. Then theoutput 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 filtercapacitor are mounted on the chassis. Changing the jumpers on the ACdistribution board (located beside the transformer assembly on the bottom of thetransmitter), configures the power transformer for 100, 120, 220, or 240 VAC; seesection 2.2 for switching and fuse information. The board also includes MOVvoltage-surge suppressors and in-rush current limiters as well as a 12 volt powersupply for the PA assembly cooling fans.

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

Shock hazard!

Do not attempt to short the capacitorterminals. A bleeder resistor willdischarge the capacitor inapproximately one minute aftershutdown.

WARNING




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4.13 RF Output Filter & Reflectometer

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

A ninth-order, elliptic, low-pass filter attenuates harmonics generated in the poweramplifier. The capacitors for the filter are circuit board pads.

The reflectometer uses printed circuit board traces for micro-strip transmissionlines. Transmission line segments (with an impedance of about 82 ohms) oneither side of a 50 ohm conductor provide sample voltages representative of thesquare root of forward and reverse power.

DC voltages, representative of forward and reflected power, go through a bulkheadfilter board to the motherboard, then to the metering board, where they areprocessed 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 boardreceives terrestrially fed RF signal and converts it to composite audio which is thenfed into the exciter board. Microprocessor controlled phase lock loop technologyensures the received frequency will not drift, and multiple IF stages ensure highadjacent channel rejection. Refer to illustrations 4–6, 6–16 and its schematic forthe following discussion.

The square shaped metal can located on the left side of the receiver board is thetuner module. The incoming RF signal enters through the BNC connector (topleft corner) and is tuned through the tuner module. Input attenuation is possiblewith jumper J1 on the top left corner of the receiver board. Very strong signalscan 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 jumpersin the top left corner of the board. The frequencies are tuned by setting switchesSW1 and SW2 (upper right corner). These two switches are read upon power upby the microprocessor (U4). The microprocessor then tunes the synthesizer ICSA1057 (U3) to the selected frequency. The switches frequency range is 87.9 Mhzat 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 frequencyinformation from pin 6 of the tuner module, then goes through a FET bufferamplifier (Q2) on its way to synthesizer IC (U3). The synthesizer feeds back a DCvoltage through two resistors to pin 4 of the tuner module. Different frequenciescause 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 theDC voltage accordingly. The microprocessor tunes the frequencies of thesynthesizer IC, but the DC tuning voltage is somewhat dependent on the tunermodule.


Generally, the voltage is around 0.5 volt DC for tuning 88.1 MHz, and from 5.5 to6.5 volts DC for tuning 107.9 MHz. The 10.7 MHz IF frequency comes out of thetuner module on pin 5 and is coupled into the first filter FL1; passes through FL1and into the IF decoder system of IC LM1865 (U1). The FL1 filter sets thebandwidth or everything outside of the bandwidth depending on the filter that isselected. It could be a bandwidth of 180 kHz where everything outside of that isfiltered out depending on the filter characteristics. A second filter (F3) is availablewhen the signal has a great amount of interference from an adjacent signal. Insuch a case, remove the jumper cap that is in the F3 position, then remove theceramic 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 therethe signal passes through F2, which is a second filter for further removal ofunwanted products, and then it goes on to the IF of that chip. The quadrature coilL4 is tuned to 10.7 MHz as per calibration procedures. This results in a lowdistortion of around 0.2 to 0.3% on the audio. The audio, still a composite at thispoint, will come out of pin 15 of that IC (U1) and go to the first buffer U9. Then itgoes through a compensation network R54 and C26, and on to the stereo decoderchip at pin 2 of U5.

When a stereo signal is present, Led 1 illuminates which indicates that left andright audio is available. Then the stereo signals go to gain stages U6A and U6B andout to the RCA jacks on the back of the cabinet. These can be used for off-airmonitoring of the audio signal. Incoming frequency can be monitored from thefrequency 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 thetransmitter. This section along with the composite signal coming out of pin 15 ofLM1865 (U1) is totally separate from the transmitter section.

StereoGenerator


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot

RF INReceiver Module(option)

Illustration 4–6 Receiver Board (optional)




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A muting circuit, consisting of C22, a 1N914 diode, R14, and varible resistor R15mutes the output when a signal is too weak to be understood. The strength of thesignal muted is determined by the adjustment of R15. Any signal below the settingof R15 is shorted to +VCC through C22 by the current drawn through R14 and thediode. 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 externalsignal processing such as advertisement injection or other forms of altering thesignal. If the jumper is installed for internal circuitry, the signal will go throughR39 to the input of U2A. This is a buffer that drives the R20 pot located on the topleft hand corner of the board. R20 sets signal gain for 100% modulation ifadjusted correctly with a full incoming 75 kHz deviation signal. Then the signalgoes through R21, R22, and C20 which, along with adjustable pot R24 and C21,forms a compensation network with some phase shifting. This allows the beststereo separation possible by adjusting and compensating for differences in FMexciter boards. The signal is buffered through U2B and finally reaches the outputconnectors P1 and P2, and on to the transmit circuitry.

The power supply is fairly straight forward. The incoming 12 volt supply goes to a7809, 9 volt regulator (VR1) which supplies all 9–volt needs on the board. The 9volts also supplies a 7805, 5 volt regulator (VR2) which supplies all 5–volt needs onthe board. Plus and minus 12 volts from the motherboard is filtered and suppliesvarious needs on the board. Finally there is a precision reference voltage suppliedthrough R50 by U7 and U8. These two 2.5 volt reference shunts act very much likea very accurate zenor diode to provide precision 5 volts to the metering board.

5–1Adjustments and Tests

Section 5—Adjustments and TestsThis section describes procedures for (1) advanced users who maybe interested in customizing or optimizing the performance ofthe transmitter and (2) service personnel who want to return thetransmitter to operational status following a maintenance proce-dure.


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 theappropriate pins of header JP1 on the audio processor board. (See section 2.9.) Ifyou change the pre-emphasis, change the de-emphasis jumpers, JP203 and JP204on 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 bringthe 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 belowthe processor gain-control threshold.

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


5.2 Stereo Generator Adjustments

5.2.1 Separation

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

Since proper adjustment of this control coincides with best stereo separation, usean 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 theRF Exciter circuit board, falls within the range specified for the frequency ofoperation. (See section 2.3.1.)

3. Feed a sine wave signal of about 2.5 kHz into the left channel at a levelsufficient to put the wideband gain-reduction indicator somewhere in themiddle of its range.

4. Set the Composite level control to produce 90% modulation as indicated onan FM monitor.

5. Apply pink noise or program material to the audio inputs and confirm, onboth 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 modulationmonitor. (The composite output should be set first, since it follows the 19 kHzLevel 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 boardwith an oscilloscope, expanding the display to view the 19 kHz component onthe horizontal centerline.

3. Switch the audio to the right-channel input. When the 19 kHz Phase isproperly adjusted, the amplitude of the 19 kHz will remain constant whenswitching between left and right.

4. Recheck the separation adjustment as described in section 5.2.1.


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 trimmercapacitor (C3). Use C3 to set the frequency of the 10.24–MHz crystal whileobserving 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 synthesizerand observe the operating frequency. (Do not connect to the 10.24–MHz clockcircuit.)

5.3.4 FSK Balance Control

An FSK signal (used for automatic identification of FM repeaters) shifts thefrequencies 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 pulsewill be less than 1 µsec wide. With an FSK input (a 20–Hz square wave at the FSKinput will work), set trim pot R45 for minimum pulse width.

The setting will vary slightly with operating frequency.


5.4 Metering Board Adjustments

5.4.1 Power Calibrate

While looking at RF Power on the digital panel meter, set the Power Calibrate trimpotentiometer 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 trimpot to 10% more than the rated power (33 W for FM30, 110 W for FM100, 275 Wfor FM250, 550 W for FM500) as indicated on an accurate external watt meter. Ifthe authorized power is less than the maximum watts, you may use the Power Setto limit the range of the RF Output control. Operation below 100 watts is notrecommended as instability can occur which could damage the transmitter.

CAUTIONPossible equipment damage!

Operation below 100 watts can causeoscillations and other problems thatcould 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 SWRcircuit automatically switches to a calibrate-check mode. (See section 4.5 for moreinformation.)

Set the digital panel meter to read SWR. With the Carrier switch off, set the SWRCAL 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 Limitcontrol, you may use this indirect method.

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


5.5 Motherboard AdjustmentsFor 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 Modulationbar graph display.

This adjustment may be made only after the Output trim pot on the StereoGenerator 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 levelsufficient to put the wideband gain-reduction indicator somewhere in themiddle of its range.

3. Set the Modulation Calibrate trim pot so that the “90” light on the front panelModulation display just begins to light.

5.7 Voltage Regulator Adjustments

JP701, a 10–pin header on the Voltage Regulator board, sets the time betweenprogram failure and carrier turnoff. Pins 1 and 2 are the two pins closest to theedge of the board. The times are approximate. Sections 2.11, 2.12, and 4.8contain 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 proportionalto 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. Setthe trim pot to its midpoint for near-optimum bias.


5.9 Performance VerificationMeasure the following parameters to receive a comprehensive characterization oftransmitter 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 ofthe 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 ofthe composite stereo signal.

Because the audio processing threshold is at 90% modulation, it is not possible tomake audio proof-of-performance measurements at 100% modulation through theaudio processor. Instead, audio data for 100% modulation is taken from the inputof 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 theaudio processing threshold.

5.9.2 De-emphasis Input Network

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


5.10 Carrier FrequencyCarrier frequency is measured at the output frequency with a frequency monitor orsuitable frequency counter.

To adjust frequency, see section 5.3.3. (FCC tolerance +/– 2000 Hz per FCC Part73.1540 and 73.1545.)

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

5.12 RF Bandwidth and RF HarmonicsYou can observe RF bandwidth and spurious emissions with an RF spectrumanalyzer.

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% stereosubcarrier, and 9% pilot per FCC Part 2.989. As an alternative, use pink noise intoone 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 tenthharmonic.

2. Emissions between 240 kHz and 600 kHz from the carrier are down at least35 dB.

3. Emissions between 120 kHz and 240 kHz from the carrier are down at least25 dB.

5.13 Pilot FrequencyThe pilot frequency should be within 2 Hz of 19 kHz. (FCC Part 73.322.) Using afrequency counter, measure 1.9 MHz at pin 1 of U209 on the Stereo Generatorboard. A 200-Hz error here corresponds to a 2-Hz error at 19 kHz. If the frequencyis off by more than 50 Hz, you may change the value of C213. (Changing C213 from56 pF to 68 pF lowers the 1.9 MHz by about 35 Hz.)


5.14 Audio Frequency ResponseFor the response tests, take the readings from an FM modulation monitor.

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

5.15 Audio DistortionMake distortion measurements from the de-emphasized output of an FMmodulation monitor.

Make audio distortion measurements for left and right channels at frequencies of 50Hz, 100 Hz, 400 Hz, 1 kHz, 5 kHz, 10 kHz, and 15 kHz. See sections 5.9.1 and5.9.2.

5.16 Modulation PercentageWhile feeding an audio signal into the left channel only, confirm that the totalmodulation percentage remains constant when switching between Mono andStereo.

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

19–kHz pilot modulation should be 9%.

5.17 FM and AM NoiseTake noise readings from a de-emphasized output of a modulation monitor.

5.18 Stereo SeparationMake left-into-right and right-into-left stereo separation measurements with an FMmodulation monitor for frequencies of 50 Hz, 100 Hz, 400 Hz, 1 kHz, 5 kHz, 10kHz, and 15 kHz.

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


5.19.1 Main Channel Into Sub

Feed the left and right channels in phase with audio (L+R) at 50 Hz, 100 Hz, 400Hz, 1 kHz, 5 kHz, 10 kHz, and 15 kHz at 100% modulation, while observing thestereo 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 ofreversing the polarity of the audio of one channel (L-R input). Using thefrequencies of 5.19.1 above, observe the main channel (L+R) level with amodulation monitor.

5.20 38 kHz Subcarrier Suppression

With no modulation, but in the Stereo mode, the 38 kHz subcarrier, as indicated onan 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 followingchecks ensure a complete performance appraisal of the transmitter:

1. Perform a physical inspection, looking for visible damage and checking thatthe 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 monitorand 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 associ-ated 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 thetemperature range of 0–50 degrees centigrade, and at line voltages from 85% to115% of rating. (See FCC Part 2.995.)

6–1Reference Drawings

Section 6—Reference DrawingsThe illustrations in this section may be useful for making adjust-ments, taking measurements, troubleshooting, or understandingthe circuitry of your transmitter.


6.1 Views

Illustration 6–1 Front View

Illustration 6–2 Rear View


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot

Power Switch

Carrier SwitchDigital Multimeter Multimeter Select

Stereo/Mono Switch

Processing Control Fault Indicators

ModulationIndicators

Audio ProcessorInput LevelIndicators Relative RF

Voltage Out

Gain Reduction/ExpansionIndicators

Input GainSwitches


R L

2 3

REMOTE I/O

RIGHT LEFT/MONO

1

FUSE

RF OutputRF OutputMonitor

SCA InputsAC Power In Remote I/O

Audio InputsAudio MonitorsCompositeInput

Power Amplifierand Cooling

Ground


Illustration 6–3 Chassis Top View

Illustration 6–4 Chassis Bottom View

front of transmitter

PowerDistributionBoard

Power RegulatorBoards

Power Transformer

Voltage RegulatorBoard

Filter Capacitors

Power AmpFans

RF Exciter

Metering

Low-pass FilterStereo Generator

Audio Processor


®

Power


Stereo


Wide Band

High Band

Audio Input

High

Low

2

-6

-12

-18

2

+6 dB +12 dB

10

20Expand Compress

RF Power

SWR

ALC

PA DC Volts

PA DC Amps

PA Temperature

Supply DC Volts

Voltmeter

SWR

Lock

Input

PA DC

PA Temp

Over

100

90

80

70

60

50

40

30

20

Pilot


6.2 Board Layouts and Schematics

Illustration 6–5 Audio Processor Board


L OUT

+5V

-5V

D3

D4

FLAT A=0

75uSEC A=1.050uSEC A=0.6725uSEC A=0.33

GAIN: U5, Pin 2 to U8, Pin 2(No Hi-band gain reduction)

C11220PF

R35240K

+12V

C120.1

R26100K

R381K

R3124.9K

1

R3424.9K 1

(+/-5.0V PK)

GAIN REDUCTION VOLTS P-PTHRESHOLD 1.1

10DB 3.520DB 11

D2

R17360K

L LP2

L LP1

+12V

-12V

C6.047

79

1

1213

2

10

14

311

U5

AD632

R1100

R2211.3K

1

6

57

U4BTL072

R2424.9K

1

C5.047

R2075K

1

R132.0K

1

R23100K 1

L VU

L IN1

L IN2

+12V

-12V

C31.0

C1100PF

C2100PF

R21K

R31K

R9 1K

R424.9K

1

R524.9K

1

R624.9K

1

C41.0

R724.9K

1

2

31

8

4

U1ATL072

6

57

U1BTL072

R830.1K

1

16

7

8

R4424.9K

R4224.9K

R4324.9K

R4524.9K

/+6DB/+12DB

R VU

R IN1

R IN2

+5V

+12V

-12V

+5V

-5V

C161.0

C151.0

C13100PF

C14100PF

R401K

R411K

R48

1K

2

31

8

4U2ATL072

6

57

U2BTL072

R1220K 1

R49

20K 1

R4730.1K

1

X012

X114

X215

X311

Y01

Y15

Y22

Y34

INH6

A10

B9

X13

Y3

U3

74HC4052

R1047K

R1147K (+/-5.0V PK)

R6024.9K

2

31

8

4

U7A

TL072

R6124.9K

C5047PF

R LP2

R LP1

+12V

+12V

+12V

-12V

-12V

-12V

C81.0

POLY

C201.0

POLY

R59100K 1

R5811.3K

1

D1

D7

D8

2

31

8

4

U4ATL072

R141.0K

1

R154991

R98100

R511.0K

1

R524991

6

57

U7BTL072

R2524.9K

1

C17.047

C18.047

R46360K

79

1

1213

2

10

14

311

U6

AD632

R164991

R534991

R5675K1

R502.0K

1

R873.3K

21

3

SW1A

R12350K

PRE-EMP.

PRE-EMP.

D6

D11 D12

R7324.9K

6

57

U10BTL072

R6724.9K

R7024.9K

R7224.9K

R3624.9K

R3724.9K

D5

Q12N5087

R64OPEN

R28OPEN

C23220PF R71

240K

C4947PF

+12V

+12V

+12V

-12V

-12V

-5V

-12V

-12V

C240.1

C290.1

C22.0027POLY

Q22N5087

R62100K

R2910K

R6510K

R3310K

R6910K

R3212K

79

1

1213

2

10

14

311

U8

AD632

R6812K

79

1

1213

2

10

14

311

U9

AD632

2

31

8

4U10A

TL072

R391K

R741K

R811K

R901K

2

31

8

4

U12ATL072

6

57

U12BTL072

R3049.9K

1

R6649.9K

1

C10.0027

POLY

D10

D9

R OUT

+5V

-5V

R1093.3K

-5V

C351.0

R10710K

R1061K

R1051M

D18560

LIGHT

3mV/DB

HEAVY

.25V/DB

EBC

R650

POT LOCATEDON DISPLAY PCB

FLAT25uS50uS75uS

D16

D17

R773.3K

100K

11

22

33

44

88

77

66

55

Q7LM394

Q3

2N5210

PROC A

PROC B

PROC C

TEST

+5V

+12V

-12V

C33.047

C34OPEN

C301.0

C31100PF

C32100PF

R7610K

R9310K

R10110K

R100120

R92

1K

D15

2

31

8

4U14A

TL072

R104OPEN

R99

3.3K

D21

R752.4K

R9420.0K

1

R9520.0K

1

R9620.0K

1

R9749.9K

1

R11249.9K

1R11549.9K

1

R11649.9K

1

1 23 45 67 8

JP1HEADER 4X2

R1033.3K

3mV/DB

-5VDC at 0DB GR4.1V at 20 DB GR

7EBC

D19R89330K

D131

1

22

33

44

88

77

66

55

Q5LM394

+5V

-5V

+5.00V+5V

+12V

-12V

+5V

-5V

VDD

VSS

VEE

C460.1

C470.1

C480.1

C25100PF

C26100PF

R7891K

R8810M

R9110M

R82120

C281.0

POLY

2

31

8

4

U13ATL072

C27.047

R863.3M

D20

R803.3K

R11149.9K

1

C381.0

C391.0

D14YEL

R853.3K

R7949.9K

1

R83

10K

54

6

SW1BIN

2

GND4

VO6

TRM5

U17

REF02

2

31

8

4 U18ATL072

+12V

-12V

+12V

-12V

+12V

-12V

C36.01

C37.01

C420.1

C430.1

C450.1

C440.1

R12110.0K 1

R1221006

57

U18BTL072

R1194.7K

R120100

C401.0

C411.0

R11810.0K1

6

57

U13BTL072

6

57

U15BTL072

C20AOPEN

C8AOPEN

R8449.9K

1

R11049.9K

1

.25V / DB0.25V / DB

2

31

8

4 U16ATL072

2

31

8

4 U15ATL072

BR GR

+12V+12V

-12V-12V

6

57

U14BTL072

6

57

U16BTL072

R113100

R117100

R10249.9K

1

R11449.9K

1

NOTES :

1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% UNLESS OTHERWISE SPECIFIED.

2. ALL CAPACITORS ARE IN MICROFARADS UNLESS OTHERWISE SPECIFIED.

SCM, FM AUDIO PROCESSOR

HI GR

3. ALL DIODES ARE 1N4148 UNLESS OTHERWISE SPECIFIED.

103202

L OUT

R OUT

12345678910

J2

RECEPT 5X2

+12V-12V/+6DB/+12DB

R VUL VU

+5.00VPROC APROC BPROC CBR GRHI GRTEST

1 23 45 67 89 1011 1213 1415 1617 1819 2021 2223 2425 26

J3

RECEPT 13X2

L IN1L IN2R IN1R IN2

L LP1L LP2R LP1R LP2

1 23 45 67 89 1011 1213 1415 1617 1819 20

J1

RECEPT 10X2

AUDIO PROCESSOR


Illustration 6–6 Stereo Generator Board


STEREO GENERATOR

OUTPUT

+12V

+6V

+12V

-12V

2

31

8

4 U4ATL072

R1210.0K

1%

R11100

D3

R583.9K

R55 24.9K

C261.0

2

31

8

4U6ATL072

C271.0

R5724.9K

R92K 1%

R5624.9K 1%

R54 24.9K 1%

C3100PF

R30 OHM

C40 OHM R5

1K

(SELECTABLE BY TEST, USE

EXTERNAL COMPOSIT IN

(3.5V P-P for 7.5KHz)

(3.5V P-P for 75KHz)

+12V

-12VC1.0027

POLY

R381M

R64991%

3 1

2

JP1

C5.0027

POLY

R73.65K

1%

C61030PF

2

31

8

4

U3ATL072

R1330

15.2 KHz LOW-PASS FILTER(8th ORDER ELLIPTICAL)

LPIN L

+6V-6V

1 2 3 4 5 6 7

141312111098

U1

LTC1064-1

14

7

+6V

R261K

Y17.6MHZ

C1356PFNPO

R251M

1 2

U7A74HC04C14

33PFNPO

C291.0

R27100

CK 1

CK 4

CLR 2

Q 3

Q 5

QC 6

QD 7

U8A74HC390

13 12

U7F

C241.0

D11N5818

C231.0

D21N5818

1 2 3 4 5 6 7

141312111098

U2

LTC1064-1

1.52 MHz

3.8 MHz

14

8

16

14

50 75

50 75

LPOUT R

INPUT R

+6V

+5.00V

CK 15

CK 12

CLR 14

QA13

QB 11

QC10

QD 9

U8B74HC390

A 13

Q11

Q10

QC 9

QD 8

CLR 12

U9B74HC393

4

5 6

U10BR29

100K 1%

C150.1

LPA

1

LPB

20

BPA

2

HPA

3

INVA

4

S1A

5

BPB

19

HPB

18

INVB

17

S1B

16

SA/B

6

VA+

7

VD+

8

LSH

9

CLKA

10

AGND

15

VA-

14

VD-

13

50/100

12

CLKB

11

U11LMF100

R3310.0K 1%

C11.01 POLY

C311.0

R28243K 1%

C301.0

C2.0027

POLY

R2330

3 1

2

JP2

R184991%

C9.0027 POLY

R193.65K 1%

C101030PF

R391M

6

57

U3BTL072

3 1

2JP4

R84.99K 1%

3 1

2JP3

C7.01 POLY

R3449.9K

1%

R204.99K

1%

R102.49K 1%

R222.49K

1%

1

2 3

U10A

74HC86

38 KHz3.0VP-P

8 7

16

SEPARATION

(•3.85V P-P)

R2041K

+12V-12V

MON L

MON R

COMP METER

SYNC OUT

MONO/STEREO

/EXT ENABLE

+12V

+6V

-12V

-6V

-12V

C170.1 R37

1K

C18.0027

POLY

R4010K

7 9

1

12 13

2

10

14

311

U12B-B 4214

R3210K

C210.1

R4720K

C37OPEN

R484.3K

R17100

R2110K

R5310K

6

57

U4BTL072

R24100

D6

X0 12

X1 13

Y0 2

Y1 1

Z0 5

Z1 3

INH 6

A 11

B 10

C 9

X14

Y15

Z 4

U574HC4053

C281.0

6

57

U6BTL072

R16100

R14 1K

R154.02K

1%

R1324.9K 1%

R2324.9K 1%

4.12K OR 4.15K IF NEEDED)

12345678910

J3

RECEPT 5X2

19 KHz3.3VP-P

19 KHZ LEVEL

STEREOX1

EXTERNAL COMPOSITE

U205 Connections

X

SCA INCOMP OUTCOMP METER

/EXT ENABLE

EXT INEXT RTN

GND

MONO/STEREO

U5Y

R4333K

R41510

123456789101112

J1

RECEPT 12X1

C190.1

C20.0027

POLY

1.9MHz

304 Khz

7

7

+12V -6V+12V +6V

C331.0UF

C341.0UF

R49240

IN 1

C

2

OUT 3

VR1LM317

C16 0.1

C321.0

R30243K

1% 9

10 8

U10C

74HC86

12

1311

U10D

A 1

QA 3

QB 4

QC 5

QD 6

CLR 2

U9A74HC393

R35

10.0K 1%

R3649.9K1%

R31100K

1%

R50910

7.6 MHz

CLK

QA

QB

QC

QD

QB XOR QD

QC XOR QD

QB XOR QC

QA XOR QC

Current at U211 pin 4.

Current at U211 pin 17.-12V

-12V -6V

C351.0

IN 1

C

2

OUT 3

VR2LM337

R52910

R51240

11 10

U7E74HC04

9 8

U7D74HC04

5 6

U7C74HC04

3 4

U7B74HC04

C3647UF

MONO

STEREO/MONO

Z

C

X0

B

Y

A

Y1

Y0

Z1

Z0

MON LMON R

+5.00VSYNC OUT

INPUT LINPUT R

GNDLPIN LLPOUT LLPIN RLPOUT R

+5.00V

123456789

101112

J2

RECEPT 12X1

U5X

U5Z

U206, pin6

/EXT EN

NOTES :______________

1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% UNLESS OTHERWISE SPECIFIED.2. ALL CAPACITORS ARE IN MICROFARADS UNLESSOTHERWISE SPECIFIED.

CROWN INTERNATIONAL, INC.1718 WEST MISHAWAKA ROAD ELKHART, IN. 46517 PHONE (219) 294-8000

DO NOT SCALE PRINT

SUPERSEDES

REV

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PE

APPROVED BY :DRAWN

CHECKED

SCALE NONE

PROJ # DWG. NO.

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JFL

NEXT ASM:FILENAME: A

SCM, FM STEREO GENERATOR

7-28-97

MLOWCM0

1 0 3 2 0 3103203A.SCM

3. ALL DIODES ARE 1N4148 UNLESS OTHERWISE SPECIFIED.

COMP OUTLPIN R

LPOUT L

R242 1K R244 10K

INPUT L

C125.5—18PF

EXT RTN

EXT IN

SCA IN

D4

D5

19 KHZ PHASE

R4610K

JB 1

TOP SIDE COMPONENT MAP, FM-VFM EXCITER UNCONTROLLED

UNLESS OTHERWISE MARKED IN RED BY CM AS A CONTROLLED COPY, COPIES OF THESE DOCUMENTS AND ASSOCIATED ELECTRONIC FILES ARE UNCONTROLLED AND ARE FOR REFERENCE ONLY.

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REV A

THESE DRAWINGS, SPECIFICATIONS AND ASSOCIATED ELECTRONIC FILES ARE THE PROPERTY OF INTERNATIONAL RADIO AND ELECTRONICS CORP., AND SHALL NOT BE REPRODUCED, COPIED, OR USED AS THE BASIS FOR THE MANUFACTURE OR SALE OF APPARATUS OR DEVICES WITHOUT PERMISSION.

SEE NOTE 10

DWG. NO. REV. A200440-SCH

H

G

F

E

D

C

B

A

1 2 3 4 5 6 7 8 9 10 11 12

H

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D

C

B

A

1 2 3 4 5 6 8 9 10 11 12

E . C . N. REV DESCRIPTIONAPPROVALS

PECHK CMDATE DWNREVISION HISTORY

THESE DRAWINGS AND SPECIFICATIONS ARE THEPROPERTY OF INTERNATIONAL RADIO CORP.AND SHALL NOT BE REPRODUCED, COPIED OR USED ASTHE BASIS FOR THE MANUFACTURE OR SALE OF APPARATUS ORDEVICES WITHOUT PERMISSION.

SHEET OFSCALE : NONE PROJ NO.FILENAME:

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C_L_SHT1_A.DOT REV. A

INTERNATIONAL RADIO AND ELECTRONICS CORP.25166 LEER DRIVE ELKHART, IN. 46514574-262-8900 WWW.IREC1.COM

IREC+12V

/LOCK

/LOCK

LOCK

+12V

GND

+5V

+5V

FSK-R

LOCK

COMPOSITE IN

TP1

+12V

RF OUT

+8V

FSK-R

88-108 MHZ

COMPOSITE IN

+8V

-12V-12V

CLKDATALOAD

8.26V+8V

+5V

DATA

LOADCLOCK

GND

+5V

REMOTE FREQUENCY CONTROL

FSK BAL.

LF SEP.

CLOCK

DATA

/ENABLE

OSC inOSC out

Fin

VDD

VDD

+5V

+12V

VV

CO

FSK

+5V

CH. SEL.

DIRECT FSK

+5V

LOCK DET.

+5V

VU5

VU5

+12V

FSK

Local/Remote

Local/Remote Frequency Select

IDAUTO ID

BAND LIMIT

FSK-ID-CHAN

TP

NOTES :

1. ALL RESISTORS ARE IN OHMS,1/4W, 5% TOL.

2. ALL CAPACITORS ARE IN MICROFARADS.

DL1GREEN

DL2RED

IN3

C2

OUT 1

VR3LM317

12345678910

11121314151617181920212223242526

J1

RECEPT 13X2

12345

SW1

12345

SW3

12345

SW2

12345

SW4

12345

SW5

IN3

C2

OUT 1

VR2LM78L05

PB1RESET

SER

10

A11

B12

C13

D14

E3

F4

G5

H6

QH

9

CL

K2

QH

7

INH

15

SH/L

D1

U274HC165

SER

10

A11

B12

C13

D14

E3

F4

G5

H6

QH

9

CL

K2

QH

7

INH

15

SH/L

D1

U174HC165

12

34

56

78

910

HD1

HE

AD

ER

5X

2

12345678910

RP1100K RPACK

123456789

10

RP2100K RPACK

R110.0K

RA21

RA32

RTC3

CLR4

VSS5

RB06

RB17

RB28

RB39 RB4 10RB5 11RB6 12RB7 13VDD 14OSC2 15OSC1 16RA0 17RA1 18

U3PIC16C61

R210.0K

R171K BECKMAN

R1868K

R1925K

R24150

R25680

R26680

R4410.0K

R4510K

R4639K

R471.0K

R481.0K

R51237

R521.27K

C133PF NPO C2

39PF NPO

C31-10PF

C5.001 POLY

C6100PF

C7.001

C9.001

C10.001

C133900PF

C19.001

C23.001

C26.001

C31.001

C32.001

C3333pF

C35.001

D11N4148

D21N4148

D31N4148

D41N4148

D5 1N4148

D91N4148

D101N4148

R51.0K

R16100K

R15100K

D81N4148

C41100PF

9 8

U4D74HC14

5 6

U4C74HC14

13 12

U4F74HC14

11 10

U4E74HC14

34

U4B74HC14

12

U4A74HC14

11

22

33

44

55

66

77

88

16 16

15 15

14 14

13 13

12 12

11 11

10 10

9 9

U6

MC145170

R4 100K

Y110.24MHZ

D71N4148

2 1

3

A2MAR-6

C22.001

R6339

12

34

56

78

VCO61POS-150

DL3AMBER

12

34

56

78

910

HD2HEADER 5X2

R3010

R431.0K

12

34

56

78

910

PL1HEADER 5X2

C2433pF NPO

R7 10

C42.001

C11 .001

C121

C14.001 POLY

R6100K

R9100K

R10100K

R11100K

R13100K

R14100K

R21100K

R121.0K

R62100

R65100K

R6110.0K

R20 1M

R41 10.0K

R28 10.0K

R27 10.0K

R42 10.0K

R40 10.0K

R231MR22

200K

C150.01

R35 499K

D121N4148

R3150K

D61N4148

R66150

R6715

R68499K

21

3

A1

MAR-6

R3815

R39100

R33100

D111N4148

C62220pF

R64 4.99K

2

31

411

U5A

MC33284P

6

57 U5B

MC33284P

9

108U5C

MC33284P

13

1214U5D

MC33284P

2

31

84

U7A

NE5532

5

67 U7B

NE5532

+5V

GND

RF OUT

8

9

C41

C291

C431

C81

C441

C401

C28 1

509

2

31

84

U8ATL072 5

67U8B

TL072C760.1

C770.1

C78 0.1

-12V

+12V

R852K

PWR. CNTRL. OFFSET

C79 0.1

-12V

R8710K

Q72IRFD9120

G

S

DD133.9V

TP2

4.5 - 8.0V

1 2

JP1JUMPER

C82.01

PWR. CNTRL TILT

+8V

SCH, FM-VFM RF EXCITER

DW 01-04-02

R8024.3K 1%

R88

30.1

K 1

%

R8926.7K 1%

R8224.3K 1%

R90

499

1%

R86

680.0

D14

6.2V 1N753A

R8110.0K

C811000pF

R835.11K 1%

R845.11K 1%

C800.1

1 FOR PROTOTYPE 01-04-02 DW

02-06-02 DW2 MODIFIED PER MIKE SENEKI

06-24-02 DW3 CHG'D R18 PER EAD MRH01. R18 WAS 91K OHM. U5 WAS C 6900-5

1%

1%

1%

1% 1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%

1%1%

1%

1%

+ C6147/20VTANT.

+ C2110/35VTANT.

+ C2710/35VTANT.

+ C3010/35VTANT.

+ C3610/35VTANT.

+ C3710/35VTANT.

+ C3810/35VTANT.

+ C3910/35VTANT.

POLY

POLY

UNLESS OTHERWISE SPECIFIED:

1 1

REFERENCE DESIGNATORS NOT USED:

C16, C17, C18, C20, C25, C34, C45-60, C63-75,Q1-71, R29, R31, R32, R34, R36, R37, R49, R50,R53-60, R69-79, VCO1-VCO60.

R8100

05-23-03 DW4 R8 WAS 1.0K OHM.246 A-G

01-29-04 DWA PRODUCTION RELEASE277 DW DP

DJ 01-05-02

DW 01-05-02

DP 01-05-02


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

D 8

169-

1


METERING

FAULT SUM

SWR LAMP

PADC LAMP

LOCK LAMP

+5V

PATEMP LAMP

R45010K

D411

J2-1

J4-8

J3-18

J3-12

J3-14

J3-20

/+28V INH

11 10

U405E74HC14

/LOCK

+5V

D406

D407

D408

D409

D410

U5

R416100K

9 8

U405D74HC14

13 12

U405F74HC14

1 2

U405A74HC14

3 4

U405B74HC14

5 6

U405C74HC14

R432100K

R49210K

+5V

J4-1

PAI LIMIT

+12V

1.00V = 10.0A

1.00V = 10VDC

FAN

REM PADCV

REM PADCA

R415120K

C407.001

C409.001

D401

U3

U3

U4

U2

-12V

J2-7

J4-4

-12V

+12V

-12V

+12V +5.00V

6

57

U402BTL072

2

31

8

4U402ATL072

R410100

R409100

R412

10K POT H

R41115K

R41333K

13

1214

U404DTL074

C405.001

D402

R431120K

2

31

4

11U403ATL074

13

1214

U403DTL074

2

31

4

11U404ATL074

R427240K

R4371M

R4251M

R42810K

R429220K

R430100K

C4081.0UF

J4-3

R4142.2M

R424100k

R42630.1K 1

5.00V = 100 deg. CTEMP OUT

REM PATEMPR4181K

R420100K 1

R421100

R41924.9K

U3

-12V

J2-4

J2-3

J2-6

J4-6

C421.001

R40710.0K 1

R406100K 1

R423240K

9

108

U403CTL074

R4081.1K 1

Parts not loaded:

R402, 403, 404

C403, 404

Q401, 402

DZ401

(Jumper under board)

C401.01

U401

R4052.49K 1

C4310.1

PAV

LB401R401

1N4148

C406.01

PAI

50mv per degree C.

R42275k

DC SUPPLY

SWR LIMIT=(R435+R436)+R436

(R435+R436)-R436---------------- = ----

150K

100K= 1.5:1

VOLTMETER

10mV/Deg. C

REM BATT

R456

1K 1

U3

J2-2

J2-8

J4-7

R453

1.1K 1

R45210K 1

R451100K 1

R454100

6

57

U403BTL074C412

0.1

C4130.1

R455100K 1

-12V

POWER SET

.001V per Watt

1mV/Degree C

10mV/Volt100mV/Amp

10mV/Volt10mV/Volt

RF LEVEL

C4100.1

R4411M

D403U4

U4

J3-8

R438120K

R435100K

R43624.9K

R44033KR434

10K POT H

9

108

U404CTL074

D404

(VFWD+VREFL)/40

RF POWER (RFV SQUARED) RF POWERSWRALCPA DCVPA DCIPA TEMPERATURESUPPLY DC VOLTSVOLTMETER

INPUT

R467

1K POTH

D412

C4110.1

U4

-12V

J2-12

R445 100K

R44610K

6

57

U404BTL074

D405

R439100K

R44251K

R444200K

R44351K

ALC

DPM IN

+5V

16FULL SCALE

1999 WATTS19.9919.99V199.9V19.99A

199.9V199.9V

199.9 Deg. C

(1.999V reads "1999")

INPUT LAMP

U8

J3-19

GND

J3-16

R44911K 1

R448100K 1

R4471K

C4220.1

X013

X114

X215

X312

X41

X55

X62

X74

INH6

A11

B10

C9

X3

U40874HC4051

J4-2

1.00V

SEL ASEL BSEL C

DPM REF

+5V

VCC

VSS

VDD

VEE

8

8

+5V

16

R1-91NUMBERS USED:

C1-29

U9

J3-2J3-4J3-6

J3-17

-12V

U8,9 pin 7

R4173.3K

+5.00V

(C2)

DZ402LM329DZ

-6.9V

X013

X114

X215

X312

X41

X55

X62

X74

INH6

A11

B10

C9

X3

U40974HC4051

C4230.1

R49010.0K 1

R4912.49K 1

C4291.0UF

C4261.0UF

+12V-12V

+12V

-12V

SWR CAL

(VFWD-VREFL)/4

+5V

R46656K

R4681K

R48824.9K

R4831M

R485100K

U6

U6

J3-9,10

C4241.0UF

C4251.0UF

C4281.0UF

+5.00V+5.00V

13

1214

U406DTL074

R486100K

R487100K

R48924.9K

Q4032N5210

R48410K

D417

R48139K

9

108

U406CTL074

R4821K

D418

C4271.0UF

IN1

C

2

OUT3

VR40178L05

J4-12

CBE

CBE

CBE

CBE

(2.5VDC at 100W)

(.135V)

R4743.3K

R47649.9K

U7

R46556K

9

108

U407CTL074

R4777.5K

R460

1K

R4641K

11

22

33

44

88

77

66

55

Q405

LM394

11

22

33

44

88

77

66

55

Q406

LM394

RFV

RF REV

RF FWD

-12V

+12V

-12V

+12V

POWER CAL

R45710K

R45822K

R459100K

R46110K

R46222K

R463100K

R46910K

R471100K

C414.01

C416.01

C418.01

D416

U6

U6

U7

U7

D4131N6263

J2-9

J2-10

J2-11

2

31

4

11

U406ATL074

C415.001

6

57

U406BTL074

C417.001

D4141N6263

2

31

4

11

U407ATL074

C419.001

D4151N6263 R472

10K POT H

6

57

U407BTL074

C420.01

R47310K

R47022K

R480100

U7

-6.9V

R47810.0K 1

13

1214

U407DTL074

R4791.1K 1

R47549.9K

(Clamp SWR reading below 5W.)

(1.00V at 100W)REM RFWATTS

J4-5

FM500METERING

103204A

-12V -12V+12V+12V

12345678910

J401

RECEPT 5X2

/LOCKALC

FAULT SUM

+5.00V

REM PATEMP

REM PADCVREM PADCAREM RFWATTS

REM BATTJ4

123456789101112

J404

RECEPT 12X1

SEL ASEL BSEL C

DPM REFSWR LAMP

PADC LAMP

LOCK LAMP

+5.00V

DPM IN

INPUT LAMP

PATEMP LAMP

RF LEVEL

J3+5.00V

12345678910

11121314151617181920

HD403

HEADER 10X2

RFV

DC SUPPLY

RF FWDRF REV

FANTEMP OUT

VOLTMETER

/+28V INH

J2

INPUT

123456789101112

J402

RECEPT 12X1

PAVPAI

dpettifor

dpettifor

dpettifor

6 - 12

dpettifor

FM30/FM100/FM250 User's Manual

1 2 3 4 5 6 7 8 9 10 11 12

A

B

C

D

E

F

G

H

121110987654321

H

G

F

E

D

C

B

A

DWG. NO. REV.1201207-SCH



65

THESE DRAWINGS AND SPECIFICATIONS ARE THEPROPERTY OF INTERNATIONAL RADIO AND ELECTRONICS CORP.AND SHALL NOT BE REPRODUCED, COPIED OR USED ASTHE BASIS FOR THE MANUFACTURE OR SALE OF APPARATUS ORDEVICES WITHOUT PERMISSION.

1 1SHEET OFSCALE : NONE PROJ NO.FILENAME:

DWG . NO . REV

1201207-SCH

TITLE:SCH, FM/IBOC MOTHER BOARD

UNCONTROLLEDUNLESS OTHERWISE MARKED IN RED INK BY CM AS ACONTROLLED COPY, COPIES OF THESE DOCUMENTSINCLUDING ASSOCIATED ELECTRONIC REPRODUCTIONSARE FOR REFERENCE ONLY.

APPROVALS

DWNCHK

CMPE

DISTRIBUTIONK

SIZE

D

Error : logo3A.jpg file not found.


IREC

1 FOR PROTOTYPE 02-05-05 DW DW

1

9

2

10

3

11

4

12

5

13

6

14

7

15

8J4

DB15

C17.01

C18.01

C19.01

C20.01

C21.01

C22.01

C23.01

C24.01

R24

220

C38OPEN

C39OPEN

C40OPEN

R13 390R14 390

R12 1K

R11 220

R15 100

R16 220

C11.01

C12

OPEN

C13.001

C14.001

C15.01

C16.01

C30.01

C31.01

C32.01

C33.01

C34.01

C35.01

C36.01

123

HD5

HEADER 3X1

1 2 3J2OPEN

C3220pF

C4220pF

C5220pF

C6220pF

C7220pF

C8220pF

C9220pFR3

1K

R4

1K

R51K

R61K

R71K

R81K

R91K

R10

240

1 2 3 4 5HD6OPEN

23

1

REF. FORXLR CON.

HILOGND

SCA

EX

T_R

TN

EX

T_I

NM

ON

_LM

ON

_R

-12V

+12V

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

HD31 26 HEADER

J5MCX

J6MCX

J1

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

RFX OUT

1 2 3 4 5 6 7 8 9 10 11 12

HD42 HEADER 12

1 2 3 4 5 6 7 8 9 10 11 12

HD44 HEADER 12

J2J4

1 2 3 4 5 6 7 8 9 10 11 12

+5.00V

D11N4148

1 2 3 4 5 6 7 8 9 10

HD41 HEADER 5 x 2

J1

V+TEMP

GND

R27 1K

R28 1K

R29 1K123456789

10

HD4

HEADER 5 x 2

123456789101112

HD21

HEADER 12

123456789101112

HD22

HEADER 12

+5.00V

LEFT

RIGHT

R IN2

R IN1

L IN2

L IN1

LPIN L

LPOUT L

LPIN R

LPOUT R

+12V

-12V

L VU

+5.00V

PROC A

PROC B

PROC C

R VU

BR GR

HI GR

1 2 3 4 5 6 7 8 9 10 11 12

ALC / METERING

123456789

1011121314151617181920

HD3

HEADER 10 x 2

+12V

1 2 3 4 5 6 7 8 9 10

+12V

-12V

C41.001

C42.001

C43.001

RF EXCITER

C10.01

R26

1KTP1

VOLTMETER

123456

HD2

HEADER 6X1 .156

+12V

12

HD7

HEADER 2 .156

C25.01

C26.01

C27.01

R25OPENQ1

IRF541

R4A

300

R3A

300Z8

OPEN

Z7

OPEN

123J1XLR

C1220pF

C2220pF

R1

1K

R2

1K

R2A300

R1A

300Z3

OPEN

Z5

OPEN

Z4 OPEN

Z6 OPEN

Z1JUMPER

Z2JUMPER

J1

123456789101112

STEREO GENERATOR

J2

123456789101112 1

23456789

10

HD23

HEADER 5 x 2

J3

12345678910

+12V

-12V

SCA

IN

EX

T R

TN

EX

T I

N

/EXT ENABLE

CO

MP

OU

T

RIG

HT

LE

FT

MON RMON L

LPIN LLPOUT LLPIN RLPOUT R

1234567891011121314151617181920

HD11

HEADER 10 x 2

J1

1234567891011121314151617181920

AUDIO PROCESSOR

12345678910

HD12

HEADER 5 x 2

J2

12345678910

123456789

1011121314151617181920212223242526

HD13

HEADER 13 x 2

J3

1234567891011121314151617181920212223242526

+12V

-12V

/+6DB

/+12DB

+5.00V

COMP METERCOMP METER

COMP METERCOMP METER

STEREO/MON

STE

RE

O/M

ON

1234567891011121314151617181920

HD61

HEADER 10 x 2

ALC

ALC

AL

CALC

ALC

FAN

TP2+12V

+12V

TP3-12V

+12V

TP4+12V

+5.00V

TP5GND

2

31U1A

TL072

C481.0+12V

C491.0-12V

R33

24.9K1%

R34 24.9K 1%

R3624.9K1%

R35

24.9K1%

Z11

OPENEXT RTN

Z10

OPEN

R37

3.9K 5

67U1B

TL072

R321K

EXT IN

R41 1KZ14

OPENSCA IN

D2

1N41

48 D3

1N41

48

R38

4.02K1%

R39

100

R40

100Z12

OPEN

Z13

OPEN

CO

MP

ME

TE

R

CO

MP

OU

T

COMP OUT

STEREO GENERATOR SHUNT

NC1

Vin2

TEMP3

GND4 TRM 5

Vout 6

NC 7

NC 8U2

REF02

+12V

C54

1.0

2

31U3A

TL072

C501.0+12V

C51

1.0-12V

5

67U3B

TL072

R43

100

C52.01

R424.7K

C541.0

Z9

OPEN

+5.00V

AUDIO PROCESSOR SHUNT

_METER PAV

_METER PAI

_METER RFW

_METER PA TEMP

_METER BATT

_FAULT SUM

_/AUTO CAR. OFF

_/CARRIER OFF

_FSK IN

_ALC

_COMPOSITE OUT

_38 KHZ OUT

_/EXT ENABLE

L IN

1

L IN2

R IN1

R IN

2

R I

N1

L IN

2

JMP1 OPEN

JMP2 OPEN

R23

220

R22

220

R21

220

R20

220

R19

220

R18

220

R17

220

FAU

LT S

UM

FAU

LT

SU

M

MET

ER B

ATT

ME

TE

R B

AT

T

ME

TE

R P

AT

EM

P

MET

ER P

ATE

MP

MET

ER R

FW

ME

TE

R R

FW

MET

ER P

AI

ME

TE

R P

AI

MET

ER P

AV

ME

TE

R P

AV

AL

C

FSK

IN

FSK IN

FSK IN

NCNC

NCNC

NC

NC

PAI

PAV

/LO

CK

FA

ULT

C28.001

C29.001

DC

SU

PPLY

TE

MP

TEMP

INPU

T

INPUT

FAN-+12V

FAN

V-M

ETER

RFV

RF

FWD

RF

REV

/LO

CK

/LOCK

/LO

CK

NC

NC

NC

38KHZ38KHZ

NC

NC

NC

NC

NC

NOTES:


1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% TOL.


DW 11-23-04

DW 11-23-04

/EXT ENABLE

/EXT ENABLE

COMP METER

INPUT CONFIGURATION CHARTNON-OMNIA BOARD INPUT IMPEDENCE

Z1, Z2 ONZ3, Z5, Z7, Z8 OFFZ4, Z6 OFF

50 KOHM

Z1, Z2 ONZ3, Z5, Z7, Z8 ONZ4, Z6 OFF

600 OHM

OMNIA BOARD AES/EBU INPUT

Z1, Z2 OFFZ3, Z5, Z7, Z8 OFFZ4, Z6 ON

ANALOG LEFT/RIGHTLEFT IN 1 LEFT IN 2

Z32

OPEN

Z33

OPEN

Z31OPEN

ADD FOR M2HD-SMOTHERBOARD ONLY

INSTALLED WHEN USINGAUDIO PROC. SHUNT CKT.

Z15

OPE

N

Z16

OPE

N

Z17

OPE

N

Z18

OPE

N

Z19

OPE

N

Z20

OPE

N

Z21

OPE

N

Z22

OPE

N

Z23

JUMPER

Z24

JUMPER

Z25

JUMPER

Z26

JUMPER

Z27

JUMPER

Z28

JUMPER

Z29

JUMPER

Z30

JUMPER

dpettifor

dpettifor

dpettifor

6 - 13

dpettifor

Reference Drawings

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" FMX50K 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 OpenZ2 Short Short Short Short Short Open Short Short Short Short Short OpenZ3 Open Open Short Open Open Open Open Open Short Open Open OpenZ4 Open Open Open Open Open Short Open Open Open Open Open ShortZ5 Open Open Short Open Open Open Open Open Short Open Open OpenZ6 Open Open Open Open Open Short Open Open Open Open Open ShortZ7 Open Open Short Open Open Open Open Open Short Open Open OpenZ8 Open Open Short Open Open Open Open Open Short Open Open OpenZ9 Short Open Open Open Open Open Short Open Open Open Open OpenZ10 Short Open Open Open Open Open Short Open Open Open Open OpenZ11 Short Open Open Open Open Open Short Open Open Open Open OpenZ12 Short Open Open Open Open Open Short Open Open Open Open OpenZ13 Short Open Open Open Open Open Short Open Open Open Open OpenZ14 Short Open Open Open Open Open Short Open Open Open Open OpenZ15 Open Open Open Open Open Open Open Open Open Open Open Open ShortZ16 Open Open Open Open Open Open Open Open Open Open Open Open ShortZ17 Open Open Open Open Open Open Open Open Open Open Open Open ShortZ18 Open Open Open Open Open Open Open Open Open Open Open Open ShortZ19 Open Open Open Open Open Open Open Open Open Open Open Open ShortZ20 Open Open Open Open Open Open Open Open Open Open Open Open OpenZ21 Open Open Open Open Open Open Open Open Open Open Open Open OpenZ22 Open Open Open Open Open Open Open Open Open Open Open Open OpenZ23 Short Short Short Short Short Short Short Short Short Short Short Short OpenZ24 Short Short Short Short Short Short Short Short Short Short Short Short OpenZ25 Short Short Short Short Short Short Short Short Short Short Short Short OpenZ26 Short Short Short Short Short Short Short Short Short Short Short Short OpenZ27 Short Short Short Short Short Short Short Short Short Short Short Short OpenZ28 Short Short Short Short Short Short Short Short Short Short Short Short ShortZ29 Short Short Short Short Short Short Short Short Short Short Short Short ShortZ30 Short Short Short Short Short Short Short Short Short Short Short Short ShortZ31 Open Open Open Open Open Open Open Open Open Open Open OpenZ32 Short Open Open Open Open Open Short Open Open Open Open OpenZ33 Short Open Open Open Open Open Short Open Open Open Open OpenJMP1 Open Open Open Open Open Open Open Open Open Open Open Open OpenJMP2 Open Open Open Open Open Open Open Open Open Open Open Open Open

dpettifor

dpettifor

dpettifor

Motherboard Configuration Chart

dpettifor

6-14

dpettifor



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

R27

D 8167-5


"110"

RED

GRN

GRN

GRN

GRN

GRN

GRN

+5V

+12V

5.00V

+12V

+12V

C6281.0UF

L218

L317

L416

L515

L614

L713

L812

L911

L1010

MODE9

RADJ8

ROUT7

DHI6

L11

V-2

V+3

DLO4

IN5

U608LM3914

YEL

6

57

U613BTL072

FOR BAR

DL648-658JP603

JUMPER

2

31

8

4

U613ATL072

R6471K

R648

1K

R627

2.7K

R6525.6K

COMPOSITE -12V

C6110.1

+12V

R64610M

Q6032N5210

Q6042N5087

R644

33K

R645100

+12VR653

1K2

31

8

4

U607ATL072

D6061N6263

D618

C6261.0UF

R62310.0K

D605

1N6263

6

57

U607BTL072

R6433.3M

R62210.0K

50mA

RED

GRN

GRN

GRN

GRN

GRN

GRN

GRN

RED

+5V

+5V

+12V

5.00V

L2

18

L3

17

L4

16

L5

15

L6

14

L7

13

L8

12

L9

11

L10

10

MODE

9

RADJ

8

ROUT

7

DHI

6

L1

1

V-

2

V+

3

DLO

4

IN

5

U604 LM3914

HI GR

G GG G YYEL

DL621-625

DL601-610

R614

1.2KQ601

MPS-A56

R6051K R613

1K

R606

330

C6021.0UF

L VU

+12V

5.00V

+12V+12V

-12V

D6011N4148

D6021N4148

JP601

R602100K

R60168K

C6011.0UF

2

31

8

4 U601ATL072

R6031K

L218

L317

L416

L515

L614

L713

L812

L911

L1010

MODE9

RADJ8

ROUT7

DHI6

L11

V-2

V+3

DLO4

IN5

U602LM3915

R6041.2K

C6041.0UF

R6091K

R VU

+12V

5.00V

+12V

+5V

R60768K

C6031.0UF

D6041N4148

D6031N4148

R608100K

JP602

R6101.2K

6

57

U601BTL072

L218

L317

L416

L515

L614

L713

L812

L911

L1010

MODE9

RADJ8

ROUT7

DHI6

L11

V-2

V+3

DLO4

IN5

U603LM3915

50mA

DL11-20

RED

GRN

GRN

GRN

GRN

GRN

GRN

GRN

REDC6070.1

C608.001

R6171K

DITHER

+5V

+5V

+12V

5.00V

L2

18

L3

17

L4

16

L5

15

L6

14

L7

13

L8

12

L9

11

L10

10

MODE

9

RADJ

8

ROUT

7

DHI

6

L1

1

V-

2

V+

3

DLO

4

IN

5

U605 LM3914

BR GR

R6181.2K

Y Y G G G G G G Y

YEL

R61533K

R61633K

C6060.1

R6111K

C605.001

Q602MPS-A56

R612

330

D607-12V

MOD. CAL.

C6100.1

R6554.7K

R64910K POT H

C612.001

DL626-635

R6241M

RED

R62510K

"PILOT"

GRN

GRN

GRN

ST/MON

/+6DB

/+12DB

+5V

DITHERC6250.1

-12V

STEREO

MONO

R62633K

5.00V

RF LEVEL

R629680

SW603

SW601

SW602

C6341.0UF R657

1K BECKMAN

DP10DP100

-12V

R6512.2K

UNITSTENS100's1000

+5V

+5V

12345678910

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

DL101DISPLAY

12345678910

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

U612 ICL7107

C6140.1

C6150.1

R638100K

DPM IN

DPM REF

C6170.1

R637470K

C616

0.1 POLY

C6180.1

C619100PFR635

100K

R636100K

C6271.0UF

DZ6016.2V

SCM, FM DISPLAY

103206

SWRSWR LAMP

PADC LAMP

LOCK LAMP

R619510

DL644-647, 659

INPUT

LOCK

INPUT

PA DC

DL644RED

DL645RED

DL646RED

DL647RED

1312

U609F74HC14

R620220K

C6091.0UF

PATEMP LAMPPA TEMP

DL659RED

+5VVCC

16

U10U11

8

VEEVSS

VDD

-12V

+12V+12V

-12V

14

U9

7

C6301.0UF

C6311.0UF

C6221.0UF

C6241.0UF

C6291.0UF

C6231.0UF

IN1

C2

OUT3

VR6017805

+12V

2

31

8

4 U606ATL072

R6315.6K

D616 D61710V P-P DITHER

DITHER6

57

U606BTL072

R63333K

C613.01

R6345.1K

-12VR632620

5 6

U609C74HC14

9 8

U609D74HC14

11 10

U609E74HC14

R630150

X013

X114

X215

X312

X41

X55

X62

X74

INH6

A11

B10

C9

X3

U61174HC4051

SWR

ALC

RF POWER

PA DC VOLTS

PA DC AMPS

SUPPLY DC VOLTS

19.99

19.99

199.9

199.9

199.9

19.99

F.S.

DECIMAL POINT

GRN

GRN

GRN

GRN

GRN

GRN

GRN

DP100

DP10

GRN

+5V

1999

R656220 DL636-643

PA TEMPERATURE

199.9VOLTMETER

UP

DOWN

R639100K

R640100K

+5V

SW605

SW606

R6281K

R6541K

+5V

1 2

U609A74HC14

3 4

U609B74HC14

A15

QA3

B1

QB2

C10

QC6

D9

QD7

UP5

CO12

DN4

BO13

LOAD11

CLR14

U61074HC193

C620.01

C632.001

C621.01

C633.001

R64110K

R64210K

SEL ASEL BSEL C

PROC A

R650100KBECKMAN

PROC B

PROC C

L VUR VU

HI GRBR GR

PROC APROC BPROC C

/+6DB/+12DB

DPM INDPM REF

MON/ST

SWR LAMP

PADC LAMP

LOCK LAMP

COMPOSITE

-12V-12V

RF LEVEL

+12V +12V-12V

5.00V

GND

5.00V

5.00V 5.00V

SEL ASEL BSEL C

+12V

INPUT

PATEMP LAMP

Pin 1, upper left from front of unit.

12345678910

11121314151617181920

J601

HEADER 10X2

12345678910

11121314151617181920

J602

HEADER 10X2

NOTES :

1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% UNLESS OTHERWISE SPECIFIED.

2. ALL CAPACITORS ARE IN MICROFARADS UNLESS OTHERWISE SPECIFIED.

DISPLAY

dpettifor

dpettifor

dpettifor

Reference Drawings

dpettifor

6 - 17


VOLTAGE REGULATOR

+6VVDD

VSS

+12V

VCC

R7231K

DZ7011N47356.2V

R722100K

R713100K

D7061N4148

+12V

R7091K

R71610K

D7071N4148

PI11

RST12

Q47

Q55

Q64

Q76

Q814

Q913

Q1015

Q121

Q132

Q143

PO9

PO10

U70274HC4060

D7021N4148

D7011N4148

6

57

U701BTL074

+12V

/CARRIER OFF

C703.001

Fo=5KHZ BPF; Q=3

/AUTO CARRIER

VDD

5 6

U703C

74HC14

3 4

U703B

74HC14

1 2

U703A

74HC14

R70210K

R70410K

R707180K

C702.001

R70591K

R7014.7K

R7034.7K

R7334.7K

CARR SW

2

31

4

11

U701ATL074

-12V

PROGRAM DETECT

VDD VDD

R725100K

COMP2AUDIO or COMPOSITE

R74810K

D7031N6263

R7065.1K

R711100K

C701.01

C704.001

13 12

U703F74HC14

11 10

U703E74HC14

D7041N626313

1214

U701DTL074

R71075K1

1

2

3

4

+IN

OSC

GND

-IN

LM3578U1

+UNREG

0.524

R7152.2K

VDD

R72010K

INPUT FAULT

R708100K

R714220

DL701GREEN R718

100K

12345678910

JP701

HEADER 5X2

D7081N4148

R71710K

11

22

33

44

88

77

66

55

U705IR21251

1

22

33

44

88

77

66

55

U704LM3578

D7101N4148

R73551

C7140.1

R724100

R73410K

TIME-OUTSELECT

MINUTES

P701

8

Q701IRF540

C723330

100V

DZ7021N9661B16V

R7121M

C7061.0POLY

C7121.0

R71910K

C7051.0POLY

Q705MPSA06

DL702RED

9

108

U701CTL074

R72124.9K

1

1

2

3

4

6

7

8VB

5

U2

6

7

8V+

5

CS

C

E

IR2125

VCC

IN

ERR

ESS VS

CS

OUT

28V ENABLE9 8

U703D

74HC14

DRVR V+

+12V

-12V

+12V

R743220R739

510

R7421K

Q704MJE15028

R7411K

(+13.5V) (+12.5V)

DZ703

ICTE-12

DZ704ICTE-12

C720220UF

50V

C7223300UF16V

L702960UH

C71822063V

C72522063V

R74010

C719100035V

Q702MPSA06

Q703MPSA56

C7171UF

SYNC

ALC

DRVR V+

+UNREG

+12V

(TO POWER REG. BOARD)

R7302.2K

R750100

-12V

PAVPAI

123456

HD704

HEADER 6

L701380UH

C711.01

R72868K

R7294.12K

1

C713100PF R738A

1.00.5W

R738A1.0

0.5W

R7374.3KR736

2KC7150.1

C72447

20V

R751JUMPER

A10124-22

D711MUR110

D7141N5822

R73282.5K

1

/LOCK FAULT

METER UNREG+12V-12V

DRVR V+

INPUT FAULT

D7151N4004

CARR SW

C7092200PF

POLY

C71056PFNPO

123456HD701

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

HD702

c 8667-5

38KHZCOMP2

/CARRIER OFF/AUTO CARRIER

FANL703

960UH

1 2 3HD703

-12V

NOTES :______________

1. ALL RESISTORS ARE IN OHMS,1/4W, 5% UNLESS OTHERWISE SPECIFIED.

2. ALL CAPACITORS ARE INMICROFARADS UNLESS OTHERWISE SPECIFIED.

THESE DRAWINGS AND SPECIFICATIONS ARE THE

SHALL NOT BE REPRODUCED, COPIED, OR USEDAS THE BASIS FOR THE MANUFACTURE OR SALEOF APPARATUS OR DEVICES WITHOUT PERMISSION.

PROPERTY OF CROWN INTERNATIONAL, INC. AND

CROWN INTERNATIONAL, INC.1718 WEST MISHAWAKA ROAD ELKHART, IN. 46517 PHONE (219) 294-8000

DO NOT SCALE PRINT

SUPERSEDES

REV

ME

EE

PE

APPROVED BY :DRAWN

CHECKED

SCALE NONE

PROJ # DWG. NO.

E.C.

JFL

NEXT ASM:FILENAME: 10.SCM A103207

8-25-97

MLOWCMO

FM VOLTAGE REGULATOR

Inductor Data

L

Wire

Turns

960uH

165

#26

380uH

#22

80

L701 L702-703

Micrometals T90 core

Remove:

U706L704R745R744C724D713

D714 1N5822 to MUR110Change: R732 100K to 49.9K

(C707)(R726)(R708)(R749)

Add: 1UF/100V between L701 and L703 under board.

Modifications for usewith 12.5V RF driver.

DZ703 1.5KE36A to ICTE-12C721, C722 3300UF to 220UF/50V

7912 regulator, using "L704" pads.Jumper "U706" pads 1 and 2.DZ705

C708220 Pf

C707.001

R726100K

R7491.5K

D709

OPEN

R727620

1 2 3 4 5

LM2576–ADJU706

R74510K 1%

D7131N5822

R7441.1K 1%

C7213300UF16V

L704960UH


Illustration 6–12 Power Regulator Board

DW

G.

NO

.R

EV

.20

0915

-SC

HC

1 2 3 4 7 8

A

B

C

D

E

F

1 2 3 4 6 7 8

A

B

C

E

F

5

THESE DRAWINGS AND SPECIFICATIONS ARE THE PROPERTY OFINTERNATIONAL RADIO AND ELECTRONICS CORP.AND ARE NOT TO BE REPRODUCED, COPIED OR USED AS THE BASISFOR THE MANUFACTURE OR SALE OF APPARATUS ORDEVICES WITHOUT PERMISSION. 1 1SHEET OFSCALE : NONE PROJ NO.FILENAME:

DWG . NO . REV.

C200915-SCH

TITLE: SCH, FM POWER REGULATORUNCONTROLLED

UNLESS OTHERWISE MARKED IN RED INK BY CM AS ACONTROLLED COPY, COPIES OF THESE DOCUMENTSINCLUDING ASSOCIATED ELECTRONIC REPRODUCTIONSARE FOR REFERENCE ONLY.

APPROVALSDWNCHKCMPE

DISTRIBUTION



65

SIZEB

Error : logo3A.jpg file not found.

B_L_SHT1_A.DOT REV. A


IREC

~

~

- + DC INPUT

TP1

TP2

ON CHASSIS

NOTES:


1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% TOL.


533

BATTERY

CIRCUIT BREAKER

110V

DW 09-30-03

R801B

24.9K

R801A27.4K

1 2

Z71 2

Z6

1 2

Z91 2

Z8

12

Z1

12

Z2

R806A330K

R805A330K

R806B

200K

R805B

200K

D8051N4148 R820

100KR80410.0K 1%

1

2

3

D803BYV72EW-150

1

2

3

D804BYV72EW-150

D8021N4148

R811

ESS4

ERR3

IN2

VCC1 VB 8

OUT 7

CS 6

VS 5

U2

IR2125

GND4

OSC3

+IN2

-IN1 V+ 8

CS 7

C 6

E 5

U801

LM3578AN

1

2

3

R80210K

DZ801

1N96

6B 1

6V

DZ8021N966B 16V

1 2Z4

1 2Z5

L801

30UH

L80330UH

L802*

Q801IRF540

R808

1.0K

R80951.0

R8072.2KR

803

82K

R8102.0K

R812A0.1

R812B0.1

DZ8031N4735 6.2V

R82110.0K

R818A2.0K

R818B2.0K

+C815330/100V

+C816330/100V

+ C817330/100V

+C810

330/100V

+C811

330/

100V

Q804MPSA06

3

26

1 8

74

U803OP-27GNB

Q802MPSA56R814

22.0K

Q8032N5087

R822

22.0K

R8161.0K 1%

R8131.0K

R815100.0

R819.04 OHM 15W 3%

R817B

2K

R817A100

C10010.015F

C802

2200

PF P

OL

YC801220PF

C8141/50V

C804.01C803

56PF

C813.01UF

C819.01UF

C8200.01UF DISK

C809.1

C818.1UF

C805100PF

C8121/50V

C808

.0027

+

C806

4.7UF/63V

123456

HD1

C 7527-2_6 HDR

P801FASTON TAB

P802FASTON TAB

P806FASTON TAB

P803FASTON TAB

P804FASTON TAB

P805FASTON TABP807FASTON TAB

P808

FASTON TABPA-DC OUT

+ UNREG IN

C10582-2C10582-2C10582-2C10582-2

PWB_REV.G

PWB_100969-1

A PRODUCTION RELEASE 10-31-03 DW

R827

1.0K

1 2Z3

DZ8061N4735 6.2V

2W 2W

5W 5W

DZ8071N966B 16V

R82830K

REF DES

FM1

UNIT CONFIGURATION

SHORT

FM30 FM100 FM250 FM500

L802

OPENOPEN OPEN OPEN OPEN

OPEN OPEN

SHORT SHORT OPEN OPEN OPENOPEN OPEN SHORT SHORT SHORTSHORT SHORT OPEN OPEN OPENSHORT SHORT SHORT SHORT OPENOPEN OPEN OPEN SHORTOPEN

H43608-1 H43395-5 H43533-1 H43533-1 H43533-1

*

*

**

*

**

*

*

*

*

*

*

2W

**PA VOLTAGE SET

JUMPERZ1

SHORT SHORT SHORTZ2SHORT

Z9 SHORT SHORT SHORT

Z8Z7Z6Z4Z5

Z3 SHORT SHORT SHORT SHORT SHORT

EURO

SHORTOPEN

OPEN

OPEN

OPENSHORT

SHORT

SHORT

SHORT

H43533-1

HARRIS M1

SHORTOPEN

OPEN

OPEN

OPENSHORT

SHORT

SHORT

OPEN

H43533-1R811 5.11K 1%3.3K 3.3K 3.3K3.3K3.3KR827R828DZ806DZ807

OPENOPENOPENOPEN

OPENOPENOPENOPEN

OPENOPENOPENOPEN

OPENOPENOPENOPEN

OPENOPENOPENOPEN

OPENOPENOPENOPEN

INSTALLED3.3K

HARRIS M2

OPENSHORT

OPEN

OPEN

SHORTSHORT

SHORT

OPEN

OPEN

H43533-13.3K

INSTALLEDINSTALLED INSTALLEDINSTALLED INSTALLEDINSTALLED INSTALLED

DW 09-30-03

DP 09-30-03

200915-SCH

DW DP

B CORRECTED Z3 AND Z6 UNIT STATUS FOR M2 AND FM100 01-29-04 DW DW DP274

C SWAPPED Z1, Z2 TO MATCH PWB 08-10-04 DW DW323 DP

dpettifor

dpettifor

dpettifor


dpettifor

6 - 20


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

R20

R19


FM500 POWER AMPLIFIER

J2

L902

R9034.7K

C904

0.01

R90451

T900

C900

0.01 R90151

C901

0.01

R90051

C9030.01

U900

CA2832

L90033uH

R9022.75W

RF DRIVER BD

C90827PF

C9075PF

L904

23.2uH

C91036PF

C90636PF

L903

10.4uH

C90510PF

C909

680PF

C902

0.01D9001N753A6.2V

J3

DZ11101N4735

6.2V

R11192003W

J5

R11202.7K

C11210.01DISC

R11125.6

2W

R11135.62W

R110115K

C1126

0.1

R111010K

R1117243W

C11380.068

C11120.01

C11130.01

C11140.01

C11150.01

R111610K

C111627PF

C1110

0.01

C11110.01

TEMP SENSE

C11220.01DISC

L112250NH

L112150NH

C112560PF

C11230.01

C11240.01

1 2 3LM35DZ

C11330.1

C11270.1

C11280.1

123456789

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

373839404142434445464748495051525354555657585960616263646566676869707172

J1

C11370.1

C11360.1

C1132

0.1

C11340.1

C11350.1

+_ B1

J2

C11310.1

C11300.1

PA OUTPUT BD

T1121

L1125A

L1125BC11220.01DISC

L112250NH

L112150NH

C112560PF

L1126C1129

0.1

T11S

R11145.6

2W

R11155.6

2W

R111010K

R11202.7K

C11210.01DISC

R11125.6

2W

R1113

5.6

2W

R110115K

R1117243W

C11120.01

C11130.01

R111610K

C11100.01

C11110.01

PA INPUT BD

L1124A

L1124BL1123

DZ11101N4735

6.2VZENER

R11192003W

PA INPUT BD

R11145.6

2W

R11155.6

2W

C1116

27PF

C11140.01

C11150.01

C11380.068

PA OUTPUT BD

T1121

C11230.01

C11240.01

B3

B2

CROWN INTERNATIONAL, INC.1718 WEST MISHAWAKA ROAD

DRAWN

CHECKED

SCALE

PROJ #

JFL

FILENAME: 1001771A.SCM

FM500 P.A.

ELKHART, IN. 46517 PHONE (219) 294-8000

DO NOT SCALE PRINT

SUPERSEDES

REV

ME

EE

PE

APPROVED BY :

NONE

DWG. NO.

E.C.

R103

NEXT ASM:

7-12-96

100177 A

THESE DRAWINGS AND SPECIFICATIONS ARE THE

SHALL NOT BE REPRODUCED, COPIED, OR USEDAS THE BASIS FOR THE MANUFACTURE OR SALEOF APPARATUS OR DEVICES WITHOUT PERMISSION.

PROPERTY OF CROWN INTERNATIONAL, INC. AND

+_

+_

NOTES :______________

1. ALL RESISTORS ARE IN OHMS,1/4W, 5% UNLESS OTHERWISESPECIFIED.

2. ALL CAPACITORS ARE INMICROFARADS UNLESSOTHERWISE SPECIFIED.

9 8 7 5 3 2 1

Q1101BLF278

Q1101BLF278

T1111P

T11S

T1111P

R111110KPOT V

R111110KPOT V

R905 10K

R900MRF 137


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

P10

421-

9


RF OUTPUT FILTER & REFLECTOMETER

103209

RF OUT

C121147PF NP0 R1203

10*R1202

75

C12047.1PF

C12069.3PF

C12085.13PF

L120394.1NH

L120487.5NH

(195MHz) (176MHz) (252MHz)

C1209A2PF

L120577.9NH

RF IN

C12021.35PF

L120290.5NH

(455MHz)

C120115.4PF

C120340.9PF

L1201250NH

C1201A10PF

C121847PF SM

R1201100

C12173.5PF

C120538.9PF

C120737.7PF

C120914.1PF C1219

47PF SM

with 200W RF in.Approx. 7V RMS1

23

HD1201

RF MONITOR

FWD

REFL

C121247PF NP0

C1213.001

C1215.01

C1214.01

D12011N6263

R120410

R1207100K

R12061K

C1216.001

*

D12021N6263

R12091K

R1205

75

R120820K

1 2 3 4 5

HD1202HEADER 5

RFV

C1220.01

R121010K

R1211100K

14

3

3

3

3

LENGTH

0.7"

0.6"

GUAGE

#17

#12

#12

#12

#12

D12031N62630.6"

0.5"

0.7"

L1201

L1202

L1203

L1204

L1205

I.D. TURNS

0.25"

0.5"

0.5"

0.5"

0.4375"

INDUCTORS

*

50-OHM LOAD. R1205 = R1202

IF NECESSARY, SELECT R1202 FORSWR READING OF 1.1 OR BETTER WITH

R1202,R1203,C1211,D1202,C1216ON UNDERSIDE OF CIRCUIT BOARD.

EXACT COIL LENGTHS ARE FACTORY-SET.

3. C1201-1209A,1217 are circuit board pads.

NOTES :______________

1. ALL RESISTORS ARE IN OHMS,1/4W, 5% UNLESS OTHERWISESPECIFIED.

2. ALL CAPACITORS ARE INMICROFARADS UNLESSOTHERWISE SPECIFIED.

dpettifor

dpettifor

dpettifor

Reference Drawings

dpettifor

6 - 25

DW

G.

NO

.R

EV

.Q

4331

0-4

P

1 2 3 4 7 8

A

B

C

D

E

F

1 2 3 4 6 7 8

A

B

C

E

F

5

THESE DRAWINGS AND SPECIFICATIONS ARE THE PROPERTY OFINTERNATIONAL RADIO AND ELECTRONICS CORP.AND ARE NOT TO BE REPRODUCED, COPIED OR USED AS THE BASISFOR THE MANUFACTURE OR SALE OF APPARATUS ORDEVICES WITHOUT PERMISSION. 1 1SHEET OFSCALE : NONE PROJ NO.FILENAME:

DWG . NO . REV.

PQ43310-4

TITLE: FM RF DRIVERUNCONTROLLED

UNLESS OTHERWISE MARKED IN RED INK BY CM AS ACONTROLLED COPY, COPIES OF THESE DOCUMENTSINCLUDING ASSOCIATED ELECTRONIC REPRODUCTIONSARE FOR REFERENCE ONLY.

APPROVALSDWNCHKCMPE

DISTRIBUTION



65

SIZEB

B_L_SHT1_A.DOT REV. A


IREC

L133uH

J1RF IN

L2 OPEN

R1010K

IN1

GN

D2

GN

D3

N/C

4

VC

C5

N/C

6

GN

D7

GN

D8

OU

T9

XU1MHW6342T

R1OPEN

C60.01

C70.01

T1

Q1BLF245

R2

OPEN

C15680pF

L3 C1010pF

C1136pF

C1236pF

C135pF

L410.4uH

L523.2uH

C1427pF

J2RF OUT

C9OPEN

R114.7K

R951

C170.01

+24VDC

C160.01

C18OPEN

1/2W

3

21

84

U2A

OPEN

5

67

U2B

OPEN

R15OPEN

R14

OPEN

G

S

D

1

J3

1

J4

R13OPEN

R12

OPEN

R8*

D31N753A6.2V

DW 08-28-03

533

1

J5

R7

OPEN

C8OPEN

2

1

3

D1OPEN

C1

.01

Vin1

GN

D2

Vout 3

VR1OPEN

R16OPEN

C2OPEN

R4

OPENR3OPEN

2

1

3

D2OPEN

C3.01

R6OPEN

+5V

R5

OPENC4OPEN

UNLESS OTHERWISE SPECIFIED:NOTE:

1. ALL RESISTORS ARE IN OHMS, 1/4 WATT +/- 5% TOL.


L6OPEN

R1751

DW 10-30-03

DP 10-30-03

C19OPEN

RT1

2.7K NTCOPEN

T

L7OPEN

C20OPEN

C21OPEN

C22OPEN

R18

0

FM30 FM100 FM250 FM500

R8 POWER LEVEL CONFIGURATION

OPEN 3 OHM 5W 2.7 OHM 5W3 OHM 5W

FOR FM100 AND FM250: 18V

FOR FM500: 20V

FOR FM30: FEED POINT FROM PWR. REGULATOR PWB.

FOR FM30:20VDC INPUT APPLIED HERE.

C522

C23

.01

C24

.01

ADDED TO PWB (200922-PWB-D IN LOCATIONSHOWN, AND DEPICTED ON COMPONENT MAP.

M PRODUCTION RELEASE 12-10-03 DW DW DP264

N XU1 WAS 200479-TERM-10 01-29-04 DW DW MH279

O PWB CHG'D TO REV. C 06-14-04 DW DW DP316

P PWB CHG'D TO REV. D 03-22-05 DW DW DP361

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dpettifor

dpettifor

6 - 26

dpettifor



FM500 CHASSIS WIRINGFM500 Chassis WiringC.Donner 2-23-98CROWN BROADCAST

AC Input, Fuse, & Filter

A

B

C

D

D

A

Gnd

Gnd

Red Blk Red/WhtBrn/Wht

Brn Wht S1A S1B

P1100V220V

120V240V

P7 P6

P5 P4 Blk/Wht

P801

P802

P803

P804P806

P805

P807

P808

Right PowerRegulator Board

P801

P802

P803

P804P806

P805

P807

P808

Red

Blk

Fan

1234

678910

123456

HD701

P1Unreg

CarrierSwitch

V+

Gnd

Power TransformerRED / WHT

RED

WHT / BLK

WHT

BLK

BRN

BRN / WHT

BLU / WHT

BLU

1

3456

2

1 2 3 4 5 6

1 2 3 4 5 6

P3

Ribbon Cable

+ BridgeRectifier

ACPowerSwitch

Ribbon C

able

On

Off

12

456

89

12131415

1718

2019

22232425

2829

313233

3536

Driver input

BNC

PA 1 DC Input

PA RF Output

BNC

3738

404142

44454647

54555657

5253

62636465

676869

7172

PA 2 DC Input

P1

P2

Outer Fans

Inner FanDriver DC Input

Mother Board Voltage RegulatorBoard

13123456

1234

6789

10Header Socket

Power Amp InterconnectBoard

J1

Bus

Bus

DC

DC

AC Distribution Board

Temp Sensor

Back view

*

* *

*Jumpered for 120VAC

On

Off

Display Board

HD561

J 601J 602

MeteringBoard

J 403Ribbon Ribbon

HD504

HD1202

RF OutputFilter & Reflectometer Board

RF Out RF In

HD505

Reflectometer Feed-Thru

P3

5 5

HD 502HD5032

Tem

p

HD702

Left PowerRegulator Board

120 VAC

20 VAC

100 VAC

57 VAC

57 VAC

12.5 VAC

CHASSIS WIRING


Illustration 6–16 Receiver Board


Receiver

7–1Service and Support

Section 7—Service and SupportWe understand that you may need various levels of support orthat the product could require servicing at some point in time.This section provides information for both of these scenarios.


7.1 ServiceThe product warranty (see opposite page) outlines our responsibility for defectiveproducts. Before returning a product for repair or replacement (our choice), callour Customer Service department using the following telephone number:

(866) 262-8917

Our Customer Service Representative will give you further instructions regardingthe return of your product. Use the original shipping carton or a new one obtainedfrom Crown. Place shipping spacers between the slide-out power amplifier assem-bly and the back panel.

Please fill out the Factory Service Instructions sheet (page 7–5) and include it withyour returned product.

7.2 24–Hour SupportIn most instances, what you need to know about your product can be found in thismanual. There are times when you may need more in-depth information or evenemergency-type information. We provide 24–hour technical assistance on yourproduct 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 bereturned promptly from our on-call technician.

7.3 Spare PartsTo obtain spare parts, call Crown Broadcast Sales at the following number.

(866) 262-8917

You may also write to the following address:

Service Manger

International Radio and Electronics Company, Inc.

25166 Leer Drive

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


Three-Year Limited Warranty

North America Only

SUMMARY OF WARRANTYWe, Crown Broadcast, a business unit of International Radio and Electronics Company, Inc., 25166 LeerDrive, Elkhart, Indiana 46515–2000 warrant to the ORIGINAL PURCHASER of a NEW Crown Broadcastproduct, for a period of three (3) years from the date of purchase by the original purchaser (the “warrantyperiod”) that the new Crown Broadcast product is free of defects in materials and workmanship and willmeet or exceed all advertised specifications for such a product. This warranty does not extend to anysubsequent purchaser or user, and automatically terminates upon sale or other disposition of ourproduct.

ITEMS EXCLUDED FROM THIS CROWN BROADCASTWe are not responsible for product failure caused by misuse, accident, or neglect. This warranty does notextend to any product on which the serial number has been defaced, altered, or removed. It does not coverdamage to loads or any other products or accessories resulting from Crown Broadcast product failure. Itdoes not cover defects or damage caused by use of unauthorized modifications, accessories, parts, orservice.

WHAT WE WILL DOWe will remedy any defect, in material or workmanship (except as excluded), in our sole discretion, byrepair, replacement, or refund. If a refund is elected, then you must make the defective or malfunctioningcomponent available to us free and clear of all liens or other encumbrances. The refund will be equal tothe actual purchase price, not including interest, insurance, closing costs, and other finance charges lessa reasonable depreciation on the product from the date of original purchase. Warranty work can only beperformed at our authorized service centers or at our factory. Expenses in remedying the defect will beborne 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 ofentry in the United States and all taxes, duties, and other custom’s fee(s) for such foreign shipments.)

HOW TO OBTAIN WARRANTY SERVICEYou must notify us of your need for warranty service not later than ninety (90) days after the expirationof the warranty period. We will give you an authorization to return the product for service. All componentsmust be shipped in a factory pack or equivalent which, if needed, may be obtained from us for a nominalcharge. Corrective actions will be taken within a reasonable time of the date of receipt of the defectiveproduct by us. If the repairs made by us are not satisfactory, notify us immediately.

DISCLAIMER OF CONSEQUENTIAL AND INCIDENTAL DAMAGESYou are not entitled to recover from us any consequential or incidental damages resulting from any defectin our product. This includes any damage to another product or products resulting from such a defect.

WARRANTY ALTERATIONSNo person has the authority to enlarge, amend, or modify this warranty. The warranty is not extended bythe length of time for which you are deprived of the use of the product. Repairs and replacement partsare provided under the terms of this warranty shall carry only the unexpired portion of this warranty.

DESIGN CHANGESWe reserve the right to change the design of any product from time to time without notice and with noobligation to make corresponding changes in products previously manufactured.

LEGAL REMEDIES OF PURCHASERThere is no warranty which extends beyond the terms hereof. This written warranty is given in lieu of anyoral or implied warranties not contained herein. We disclaim all implied warranties, including withoutlimitation any warranties of merchantability or fitness for a particular purpose. No action to enforce thiswarranty 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


Notes:


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

International Radio and Electronics Company, Inc.

25166 Leer Drive

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

For units in warranty (within 3 years of purchase from any authorized Crown Dealer): We pay forground UPS shipments from anywhere in the continental U.S. and Federal Express Second Day servicefrom Hawaii and Alaska to the factory and back to you. Expedited service/shipment is available for anadditional charge. You may ship freight collect (COD for cost of freight) or forward your receipt forshipping 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 BroadcastCustomer Service at:

Telecphon: (574) 262-8900

Fax: (574) 262-5399

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 COD Please Quote before servicing

Card Number: Exp. Date: Signature:

Factory Service Instructions

Appendix–1FM500 User's Manual

Appendix

Transmitter Output Efficiency

Appendix–2 FM500 User's Manual

Transmitter efficiency outputRF 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.

G–1Glossary

GlossaryThe following pages define terms and abbreviations usedthroughout this manual.

A B C

G–2 FM500 User's Manual

A B CAF Audio Frequency; the frequencies between 20 Hz

and 20 kHz in the electromagnetic spectrum.

ALC Automatic Level Control

AM Amplitude Modulation; the process of impressinginformation on a radio-frequency signal byvarying its amplitude.

bandwidth The range of frequencies available for signalling.

BCD Binary-Coded Decimal; a digital system that usesbinary 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 entireaudio spectrum as opposed to the spectruminfluenced by the pre-emphasis; also called"Wideband."

carrier A continuous signal which is modulated with asecond, information-carrying signal.

crosstalk In FM broadcasting, this term generally refers tothe interaction between the main (L+R) and thesubcarrier (L–R) signals as opposed to "separa-tion" which generally refers to leakage betweenleft (L) and right (R) channels.

density (program) A high average of modulation over time.

deviation The amount by which the carrier frequencychanges either side of the center frequency.

DIP Dual In-line Pins; term used to describe a pinarrangement.

distortion The unwanted changes in signal wave shape thatoccur during transmission between two points.

DPM Digital Panel Meter

EPROM Erasable Programmable Read Only Memory

ESD Electrostatic Discharge; a discharge that ispotentially destructive to sensitive electroniccomponents.

G–3Glossary

exciter (1) A circuit that supplies the initial oscillatorused in the driver stage. (2) A transmitter con-figuration which excludes stereo generation andaudio processing.

FET Field-Effect Transistor

frequency synthesizer A circuit that generates precise frequency signalsby means of a single crystal oscillator in conjunc-tion with frequency dividers and multipliers.

FM Frequency Modulation; the process of impressinginformation on a radio signal by varying itsfrequency.

FSK Frequency Shift Keying; an FM technique forshifting the frequency of the main carrier at aMorse code rate. Used in the on-air identifica-tion of frequencies.

gain reduction The process of reducing the gain of a givenamplifier.

harmonics Undesirable energy at integral multiples of adesired, fundamental frequency.

HF Hight Frequency; Frequencies in the 3.0 to 30.0MHz 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 torepresent an information-carrying signal.

MOSFET Metal Oxide Semiconductor Field Effect Transis-tor; a voltage-controlled device with high inputimpedance 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

G–4 FM500 User's Manual

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 audiofrequencies; made possible by a high-pass filter.

processing The procedure and/or circuits used to modifyincoming audio to make it suitable for transmis-sion.

receiver An option which adds incoming RF capability toan existing transmitter. See also "Translator."

RF Radio Frequency; (1) A specific portion of theelectromagnetic spectrum between audio-frequency and the infrared portion. (2) A fre-quency useful for radio transmission (roughly 10kHz and 100,000 MHz).

SCA Subsidiary Communications Authorization; see"subcarrier."

S/N Signal to Noise

spurious products Unintended signals present on the transmissionoutput terminal.

stability A tolerance or measure of how well a component,circuit, or system maintains constant operatingconditions over a period of time.

stereo pilot See "pilot."

stereo separation The amount of left-channel information thatbleeds into the right channel (or vice versa).

subcarrier A carrier signal which operates at a lower fre-quency than the main carrier frequency andwhich modulates the main carrier.

suppression The process used to hold back or stop certainfrequencies.

G–5Glossary

SWR Standing-Wave Ratio; on a transmission line, theratio of the maximum voltage to the minimumvoltage or maximum current to the minimumcurrent; also the ratio of load impedance tointended (50 ohms) load impedance.

THD Total Harmonic Distortion

translator A transmitter designed to internally change anFM signal from one frequency to another forretransmission. Used in conjunction with terres-trial-fed networks.

satellator A transmitter equipped with an FSK ID option forrebroadcasting a satellite-fed signal.

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

Wideband See "broadband."

VCO Voltage-Controlled Oscillator

Index–1

IndexSymbols

19–kHzlevel adjustment 5–3phase adjustment 5–3

A

AC. See power: inputALC 3–3, 3–8, 4–8altitude

operating range 1–8amperes

PA DC 3–3, 3–8amplifier

reference drawings 20RF 4–13

bias set 5–6antenna 2–9

mismatch 3–3applications 1–3audio

broadband 3–5distortion 5–9frequency 5–9high 3–5input connectors 4–3input level 3–5monitor connections 2–12, 4–5performance 5–7pre-emphasized 3–5processing 3–5, 4–9wide 3–5

audio processor 3–6adjustments 5–2board location 4–3bypass 2–11, 2–12, 4–9circuit description 4–3indicators 3–5input 3–5reference drawings 6–4

B

backuptransmitter use 1–4

bandwidthRF 5–8

battery. See power: inputBessel nulls 5–9

bias set 5–6booster

transmitter use 1–4broadband. See audio: broadbandbypass

audio processor 2–12, 4–9

C

cablesaudio input 2–10

carrier 4–9, 5–8automatic turnoff 2–13, 3–8, 5–6, 5–

10frequency 5–8, 5–10

carrier switch 3–4, 5–5Channel. See frequencychannel. See frequency

main 5–10main into sub 5–10sub into main 5–10

chassiscircuit 4–13

circuit boardsaudio processor 4–3, 6–4display 14metering 10motherboard 12power regulator 18RF exciter 8stereo generator 4–5, 6voltage regulator 16

circuitschassis 4–13display 4–10metering 4–8motherboard 4–9part numbering 4–2power regulator 4–12RF exciter 4–6stereo generator 4–4voltage regulator 4–11

componentsnumbering 4–2

compositeinput 2–11input connection 2–11output

Index–2 FM500 User's Manual

adjustment 5–3connectors

audio input 2–10audio monitoring 2–12composite in 2–11remote I/O 2–11, 2–13RF input 2–9RF output 2–9RF output monitoring 2–9SCA In 2–11XLR 2–11, 4–3

cooling fan 3–2control 4–9

coverage area 1–4crosstalk 1–7

measurements 5–9current limit

PA 5–5

D

DC. See power: inputde-emphasis 2–12, 5–2, 5–7

jumpers 2–12delay

program failure to carrier turnoff 2–13, 5–6

dimensions 1–8DIP

socket 2–10, 4–9display

circuit description 4–10front panel 3–2, 3–5, 3–7

modulation calibration 5–6display board

reference drawings 14distortion 1–7

audio 5–9harmonic 4–5

E

emissions 5–8exciter. See RF exciter

configuration 1–4

F

fancontrol 4–9

faultindicators 4–10input 3–8lock 3–8power 3–8servicing 3–8SWR 3–8

temperature 3–8FCC guidelines 1–8, 5–8, 5–10filter

RF output 22frequency

carrier 5–8, 5–10measurement 5–4pilot 5–8receiver 2–7response 5–9selection 2–5, 5–4

receiver 2–7samples 2–6

synthesizer 5–10frequency synthesizer. See RF exciter

adjustments 5–4front panel

display modulation calibration 5–6FSK 1–5, 1–6

measurement 5–4

G

gain control 3–5gain reduction 4–4gain switches

input 3–6

H

harmonic distortion 4–5harmonics 5–8heatsink 3–8highband 3–5

processing 4–4humidity

operating range 1–8

I

I/O connector 1–2, 2–13pinout 2–13

indicatorsaudio processor 3–5fault 3–8, 4–10highband 3–5LED 3–5, 3–7, 4–10pilot 3–5wideband 3–5, 5–6

inputaudio connections 2–10composite 2–11fault 3–8gain switches 3–5program

fault 2–13SCA connection 2–11

Index–3

L

labels 1–10LEDs 3–5, 4–10line voltage 2–3lock

status 4–7lock fault 3–8

M

metering 1–2circuit description 4–8

metering boardadjustments 5–5location 4–8, 4–15reference drawings 10

modulation 2–11, 3–5, 5–3, 5–7, 5–8calibration 5–6compensator 2–6display 3–5percentage 3–5, 5–9

monitoraudio 2–12, 4–5

monooperation 2–11, 3–6

motherboardcircuit description 4–9reference drawings 12

multimeter 3–7front panel 3–3

N

networkssatellite-fed 1–6terrestrial-fed 1–5

noise 1–7, 3–8measurements 5–9

O

operating environment 1–8, 2–2options 1–3, 1–4, 1–6output

power 1–7, 3–7display 3–7

output filter 4–14

P

part numbering 4–2parts

spares 7–2performance

checklist 5–7tests 5–10

pilot frequency 5–8

pilot indicator 3–5power

AC supply 4–13AC voltage selection 2–3amplifier

reference drawings 20fault 3–8input 1–8, 2–3

FCC guidelines 5–10output 1–3, 1–7, 5–8

display 3–7output filter 4–14regulator

circuit description 4–12RF 3–3, 3–7RF amplifier 4–13transformer 4–13

power regulator boardreference drawings 18

power switch 3–4pre-emphasis 1–7, 4–4, 5–2, 5–7

curve 2–12networks 4–3

processingaudio 2–12, 3–5control 3–6control setting 3–2highband 3–5, 4–4

processoraudio

bypass 2–12program failure 2–13, 5–10program source 2–10, 3–6

R

receiverfrequency selection 2–7option 1–5specifications 1–9

reflectometer 4–14, 22regulatory approvals 1–8remote control 1–2remote I/O

connector 2–13pinout 2–13

remote operation 2–13repair

warranty 7–3

Index–4 FM500 User's Manual

RFamplifier 4–13

bias set 5–6bandwidth 1–8, 5–8exciter 2–5, 2–11

board location 2–5, 4–6circuit description 4–6reference drawings 8

input 1–5, 2–9output 1–2, 1–5, 1–7, 3–3, 3–7

impedance 1–7output filter 4–14, 22tuning 2–7

S

safety 1–10satellator

transmitter use 1–6SCA 1–5

input connection 2–11sensitivity

monaural 1–9stereo 1–9

separationstereo 1–7stereo generator 5–3

servicewarranty 7–3

Service Instructions 7–5specifications

receiver 1–9transmitter 1–7

stand-alonetransmitter use 1–4

stereoseparation 1–7, 5–9

stereo generator 1–2, 2–12adjustments 5–3board location 4–5bypassing 2–11circuit description 4–4reference drawings 6

subcarrier 5–1038–kHz 5–10

suppressionsubcarrier 1–7

switchescarrier 3–2, 3–4, 5–5input gain 3–5, 3–6Normal-Bypass 2–12, 4–9power 3–4receiver 2–7stereo-mono 3–2, 3–6

SWR 3–7calibrate 5–5fault 3–8

SWR fault 4–9synchronization 4–11synthesizer. See RF exciter

T

temperaturefault 3–8, 4–9operating range 1–8, 5–10PA 3–3, 3–8

test pointvoltage 3–8

testsperformance 5–7, 5–10

time-outprogram input failure 2–13

transformer 4–13translator

transmitter use 1–5

V

VCO 4–6voltage

AC selection 2–3voltage regulator 3–8

adjustments 5–6circuit description 4–11reference drawings 16

voltage selection 2–3voltmeter

display 3–8volts

PA DC 3–3, 3–8VSWR 1–2, 2–9

W

Warranty 7–3weight 1–8wideband 3–5, 5–6

X

XLR connectors 2–10

R (continued)

Crown FM500

Documents

Transcript of Crown FM500