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
1–3Getting Acquainted
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
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
1–4 FM500 User's Manual
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.
1–5Getting Acquainted
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
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
1–6 FM500 User's Manual
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
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
1–7Getting Acquainted
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
1–8 FM500 User's Manual
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
1–9Getting Acquainted
1.4 Receiver SpecificationsMonaural Sensitivity (demodulated, de-emphasized)
3.5 µV for signal-to-noise > 50 dB
12.6 µV for signal-to-noise > 60 dB
Stereo Sensitivity (19–kHz pilot frequency added)
2.8 µV for signal-to-noise > 40 dB
8 µV for signal-to-noise > 50 dB
31 µV for signal-to-noise > 60 dB
Connector Standard type N, 50 Ω
Shipping Weight 1 lb
1–10 FM500 User's Manual
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.
®
2–2 FM500 User's Manual
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.
2–4 FM500 User's Manual
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
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
MEGAHERTZ .1 .01
2–6 FM500 User's Manual
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
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
2–8 FM500 User's Manual
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)
2–10 FM500 User's Manual
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
SCA IN COMPOSITE IN MONITOR
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.
2–12 FM500 User's Manual
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
SCA IN COMPOSITE IN MONITOR
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.
SCA IN COMPOSITE IN MONITOR
R L
2 3
REMOTE I/O
RIGHT LEFT/MONO
1
Remote I/O
2–14 FM500 User's Manual
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.
3–2 FM500 User's Manual
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.
FM500FM BROADCAST TRANSMITTER
Power
CarrierModulationFault
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.
3–4 FM500 User's Manual
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
FM500FM BROADCAST TRANSMITTER
Power
CarrierModulationFault
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.
3–6 FM500 User's Manual
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).
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
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.
3–8 FM500 User's Manual
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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4–2 FM500 User's Manual
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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
4–3Principles of Operation
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
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
4–4 FM500 User's Manual
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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,
4–5Principles of Operation
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
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
4–6 FM500 User's Manual
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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
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
4–7Principles of Operation
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.
4–8 FM500 User's Manual
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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.
Illustration 6–8 and accompanying schematic complement this discussion.
PA voltage and current come from a metering shunt on the power regulator board.The PAI input is a current proportional to PA current; R405 converts the 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
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
4–9Principles of Operation
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.
4–10 FM500 User's Manual
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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.
Illustration 6–10 and accompanying schematic complement this discussion.
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.
4–11Principles of Operation
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.
Illustration 6–11 and accompanying schematic complement this discussion.
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).
4–12 FM500 User's Manual
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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.
Illustration 6–12 and accompanying schematic complement this discussion.
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.
4–13Principles of Operation
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
4–14 FM500 User's Manual
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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.
4–15Principles of Operation
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
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
RF INReceiver Module(option)
Illustration 4–6 Receiver Board (optional)
4–16 FM500 User's Manual
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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.
5–2 FM500 User's Manual
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.
5–3Adjustments and Tests
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.
5–4 FM500 User's Manual
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.
5–5Adjustments and Tests
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.
5–6 FM500 User's Manual
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.
5–7Adjustments and Tests
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.
5–8 FM500 User's Manual
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.)
5–9Adjustments and Tests
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.
5–10 FM500 User's Manual
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.
6–2 FM500 User's Manual
6.1 Views
Illustration 6–1 Front View
Illustration 6–2 Rear View
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
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
SCA IN COMPOSITE IN MONITOR
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
6–3Reference Drawings
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
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
6–4 FM500 User's Manual
6.2 Board Layouts and Schematics
Illustration 6–5 Audio Processor Board
6–5Reference Drawings
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
6–6 FM500 User's Manual
Illustration 6–6 Stereo Generator Board
6–7Reference Drawings
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
ME
EE
PE
APPROVED BY :DRAWN
CHECKED
SCALE NONE
PROJ # DWG. NO.
E.C.
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.
SIZE B
DWG. NO. 200440-PWA SCALE: N/A PROJECT #: 509 SHEET: 1 OF 1
PWB: 200440-PWB-A.PCB M200440PT-A.DOC
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
G
F
E
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:
DWG . NO . REVA200440-SCH
TITLE:
UNCONTROLLEDUNLESS OTHERWISE MARKED IN RED INK BY CM AS ACONTROLLED COPY, COPIES OF THESE DOCUMENTSINCLUDING ASSOCIATED ELECTRONIC REPRODUCTIONSARE FOR REFERENCE ONLY.
APPROVALSDWNCHKCMPE
DISTRIBUTIONK
SIZE
C
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
6–10 FM500 User's Manual
Illustration 6–8 RF Metering Board(Add 400 to component designators for schematic reference)
D 8
169-
1
6–11Reference Drawings
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
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
E . C . N. REV DESCRIPTIONAPPROVALS
PECHK CMDATE DWNREVISION HISTORY
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.
INTERNATIONAL RADIO AND ELECTRONICS CORP.25166 LEER DRIVE ELKHART, IN. 46514574-262-8900 WWW.IREC1.COM
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:
UNLESS OTHERWISE SPECIFIED:
1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% TOL.
2. ALL CAPACITORS ARE IN MICROFARADS.
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
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
6–14 FM500 User's Manual
Illustration 6–10 Display Board(Add 600 to component designators for schematic reference)
R27
D 8167-5
6–15Reference Drawings
"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
6–17Reference Drawings
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
6–18 FM500 User's Manual
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
E . C . N. REV DESCRIPTIONAPPROVALS
PECHK CMDATE DWNREVISION HISTORY
65
SIZEB
Error : logo3A.jpg file not found.
B_L_SHT1_A.DOT REV. A
INTERNATIONAL RADIO AND ELECTRONICS CORP.25166 LEER DRIVE ELKHART, IN. 46514574-262-8900 WWW.IREC1.COM
IREC
~
~
- + DC INPUT
TP1
TP2
ON CHASSIS
NOTES:
UNLESS OTHERWISE SPECIFIED:
1. ALL RESISTORS ARE IN OHMS, 1/4W, 5% TOL.
2. ALL CAPACITORS ARE IN MICROFARADS.
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
6–20 FM500 User's Manual
Illustration 6–13 Power Amplifier(Add 1100 to component designators for schematic reference)
R20
R19
6–21Reference Drawings
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
6–22 FM500 User's Manual
Illustration 6–14 RF Output Filter(Add 1200 to component designators for schematic reference)
P10
421-
9
6–23Reference Drawings
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.
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
E . C . N. REV DESCRIPTIONAPPROVALS
PECHK CMDATE DWNREVISION HISTORY
65
SIZEB
B_L_SHT1_A.DOT REV. A
INTERNATIONAL RADIO AND ELECTRONICS CORP.25166 LEER DRIVE ELKHART, IN. 46514574-262-8900 WWW.IREC1.COM
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.
2. ALL CAPACITORS ARE IN MICROFARADS.
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
6–26 FM500 User's Manual
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
6–27Reference Drawings
Illustration 6–16 Receiver Board
6–28 FM500 User's Manual
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.
7–2 FM500 User's Manual
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
7–3Service and Support
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
7–4 FM500 User's Manual
Notes:
7–5Service and Support
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)