Revision Control Revision Print Date Initial Release (K80713–9) June 1996 Revision 1 (101033–1) November 1996 Revision 2 (101033–2) August 1997 Revision 3 (900239–1) February 1998 Revision 4 (900239–1) October 1998 Revision 5 (901047-1) October 1999 Revision 6 (901047-2) May 2000 Revision 7 March 2002 Revision 8 February 2006 Important Notices ©2006, Crown Broadcast, a division of International Radio and Electronics, Inc.
Contents Section 1—Getting Acquainted ..................................... 1–1 1.1 Your Transmitter ............................................................................................... 1–2 1.2 Applications and Options ................................................................................... 1–3 1.2.1 Stand-Alone .................................................................................................. 1–4 1.2.2 Backup ............................................................
Section 3—Operation ................................................. 3–1 3.1 Initial Power-up Procedures .............................................................................. 3–2 3.2 Power Switches................................................................................................. 3–4 3.2.1 DC Breaker .................................................................................................... 3–4 3.2.2 Power Switch ..............................................................
Section 5—Adjustments and Tests ................................. 5–1 5.1 Audio Processor Adjustments ........................................................................... 5–2 5.1.1 Pre-Emphasis Selection ................................................................................ 5–2 5.1.2 Pre-Emphasis Fine Adjustment ..................................................................... 5–2 5.2 Stereo Generator Adjustments ..........................................................................
Section 6—Reference Drawings .................................... 6–1 6.1 Views ................................................................................................................ 6–2 6.2 Board Layouts and Schematics ......................................................................... 6–4 Section 7—Service and Support .................................... 7–1 7.1 Service .............................................................................................................. 7–2 7.
I INFORMATION Section 1—Getting Acquainted This section provides a general description of the FM500 transmitter and introduces you to safety conventions used within this document. Review this material before installing or operating the transmitter.
I 1.1 Your Transmitter The FM500 is a member of a family of FM stereo broadcast transmitters. Crown transmitters are known for their modularity, ease-of-use, and reliability. The modularity is most apparent in the standard transmitter configuration which incorporates audio processing, stereo generation, and RF amplification without compromised signal quality. A single Crown transmitter can replace several pieces of equipment in a traditional system.
1.2 Applications and Options Crown transmitters are designed for versatility in applications. They have been used as stand-alone and backup transmitters and in booster, translator, and satellator applications. The following discussion describes these applications further. Model numbers describe the configuration of the product (which has to do with its intended purpose) and the RF output power which you can expect. The number portion of each name represents the maximum RF output power.
I 1.2.1 Stand-Alone In the standard configuration, the FM500 is an ideal stand-alone transmitter. When you add an audio source (monaural, L/R stereo, or composite signal), an antenna, and AC power, the transmitter becomes a complete FM stereo broadcast station, capable of serving a community. As stand-alone transmitters, Crown units often replace multiple pieces of equipment in a traditional setup (exciter, audio processor, RF amplifier). 1.2.
1.2.5 Translator A receiver configuration (FM500R, for example) takes an exciter configuration and adds receiver circuitry as well. This added feature makes the FM500 ideal for translator service in terrestrial-fed networks. These networks represent a popular and effective way to increase your broadcasting coverage. Translators, acting as repeater emitters, are necessary links in this chain of events.
I 1.2.6 Satellator Another option is available for all configurations—an FSK Identifier (FSK IDer). This added feature enables the FM500 to transmit its call sign or operating frequency in Morse Code. This option is intended for use in satellite-fed networks. Transmitters equipped in this fashion are often known as "satellators.
1.3 Transmitter/Exciter Specifications Frequency Range 87 MHz–108 MHz (65 MHz–73 MHz optionally available) RF Power Output 100–550 watts (VSWR 1.
I AM S/N Ratio Asynchronous and synchronous noise better than NAB recommendations RF Bandwidth ±120 kHz, better than –35 dB ±240 kHz, better than –45 dB RF Spurious Products Better than –70 dB Operating Environment Temperature (0–50o C) Humidity (0–80% at 20o C) Maximum Altitude (3,000 meters; 9843 feet) AC Power 100, 120, 220, or 240 volts (+10%/–15%); 50/60 Hz Regulatory Type notified for FCC parts 73 and 74; Meets FCC, DOC, and CCIR requirements Dimensions 17.8 x 41.9 x 44.5 cm (7.0 x 16.
1.4 Receiver Specifications Monaural Sensitivity (demodulated, de-emphasized) 3.5 µV for signal-to-noise > 50 dB 12.6 µV for signal-to-noise > 60 dB Stereo Sensitivity (19–kHz pilot frequency added) 2.
I 1.5 Safety Considerations Crown Broadcast assumes the responsibility for providing you a safe product and safety guidelines during its use. “Safety” means protection to all individuals who install, operate, and service the transmitter as well as protection of the transmitter itself. To promote safety, we use standard hazard alert labeling on the product and in this manual. Follow the associated guidelines to avoid potential hazard. 1.5.1 Dangers DANGER represents the most severe hazard alert.
® Section 2—Installation This section provides important guidelines for installing your transmitter. Review this information carefully for proper installation.
CAUTION Possible equipment damage! Before operating the transmitter for the first time, check for the proper AC line voltage setting and frequency selection as described in sections 2.3 and 2.4. 2.1 Operating Environment You can install the FM transmitter in a standard component rack or on a suitable surface such as a bench or desk. In any case, the area should be as clean and wellventilated as possible. Always allow for at least 2 cm of clearance under the unit for ventilation.
2.3 Power Connections The FM500 operates on 100, 120, 220, or 240 volts AC (50 or 60 Hz; single phase). As shipped (factory default settings), the FM500 operates on 120 volts at 60 Hz. If you are operating the transmitter at 120 volts you do not need to make any changes. To operate the FM500 at 100, 220, or 240 volts, a few changes are necessary. To change the voltage setting, follow these steps: 1. Disconnect the power cord if it is attached. 2. To set the input voltage for 100 volts, skip to step 7.
7. Turn the transmitter upside down and remove the bottom cover. Note: The front panel filter grill must be removed to expose all of the bottom Power Distribution Board front of transmitter Illustration 2–4 Underside of Transmitter—Bottom Cover Removed cover screws for bottom cover removal and installation. 8. Locate the power distribution circuit board on the left side next to the large transformer cover. See Illustration 2–4. 9.
2.4 Frequency (Channel) Selection You may select an operating frequency of 87 to 108 MHz in the FM broadcast band with 100 kHz channel spacing (10 kHz spacing is optional with the addition of a fifth rotary selector switch). To adjust the operating frequency, follow these steps: 1. Remove the top cover by removing 15 screws. 2. Locate the RF Exciter board and identify the frequency selector switches which will be used to change the setting. See Illustrations 2–5 and 2–6.
3. Use small flat blade screwdriver or another suitable device to rotate the switches to the desired setting. (The selected number will appear directly above the white indicator dot on each switch.) See examples of selected frequencies in the illustration below. = 88.1 MHz = 107.9 MHz Illustration 2–7 Two Sample Frequency Selections 4. If you have the receiver option, proceed to section 2.5 to set the incoming frequency. Otherwise, replace the top cover. 2.4.
2.4.2 RF Tuning Adjustments All the RF stages are broadband to cover the 88 to 108 MHz broadcast band. The RF amplifier stages require no tuning. 2.5 Receiver Frequency Selection If you have a transmitter equipped with the receiver option, you will need to set the receiving or incoming frequency. 1. With the top cover removed, locate the receiver module and the two switches (labeled SW1 and SW2). 2. Use the table on the following pages to set the switches for the desired incoming frequency. 3.
Frequency SW1 SW2 Frequency SW1 SW2 Frequency SW1 SW2 Frequency SW1 SW2 87.9 88.0 88.1 88.2 88.3 88.4 88.5 88.6 88.7 88.8 88.9 89.0 89.1 89.2 89.3 89.4 89.5 89.6 89.7 89.8 89.9 90.0 90.1 90.2 90.3 90.4 90.5 90.6 90.7 90.8 90.9 91.0 91.1 91.2 91.3 91.4 91.5 91.6 91.7 91.8 91.9 92.0 92.1 92.2 92.3 92.4 92.5 92.6 92.7 92.8 92.9 0 8 0 8 0 8 0 8 0 8 0 8 0 8 0 8 0 8 0 8 0 8 0 8 0 8 0 8 0 8 0 8 1 9 1 9 1 9 1 9 1 9 1 9 1 9 1 9 1 9 1 93.0 93.1 93.2 93.3 93.4 93.5 93.6 93.7 93.8 93.9 94.0 94.1 94.2 94.
2.6 RF Connections Connect the RF load, an antenna or the input of an external power amplifier, to the type-N, RF output connector on the rear panel. VSWR should be 1.5:1 or better. WARNING Severe shock hazard! Do not touch the inner portion of the RF output connector when transmitter power is on. The RF monitor is intended primarily for a modulation monitor connection. Information gained through this connection can supplement that which is available on the transmitter front panel displays.
2.7 Audio Input Connections Attach audio inputs to the Left and Right XLR connectors on the rear panel. (The Left channel audio is used on Mono.) Pin 1 of the XLR connector goes to chassis ground. Pins 2 and 3 represent a balanced differential input with an impedance of about 50 kΩ. They may be connected to balanced or unbalanced left and right program sources. The audio input cables should be shielded pairs, whether the source is balanced or unbalanced.
2.8 SCA Input Connections You can connect external SCA generators to the SCA In connectors (BNC-type) on the rear panel. The inputs are intended for the 60 kHz to 99 kHz range, but a lower frequency may be used if the transmitter is operated in Mono mode. (The 23 to 53 kHz band is used for stereo transmission.) For 7.5 kHz deviation (10% modulation), input of approximately 3.5–volts (peak-to-peak) is required.
SCA IN RIGHT MONITOR COMPOSITE IN R LEFT/MONO L REMOTE I/O 1 2 3 Composite Input (BNC) Connector Audio Monitor (RCA) Jacks Illustration 2–13 Composite In and Audio Monitor Connections 2.10 Audio Monitor Connections Processed, de-emphasized samples of the left and right audio inputs to the stereo generator are available at the Monitor jacks on the rear panel. The signals are suitable for feeding a studio monitor and for doing audio testing.
2.13 Program Input Fault Time-out You can enable an automatic turn-off of the carrier in the event of program failure. To enable this option, see the table on the next page. The time between program failure and carrier turn-off is set by a jumper (JP701) on the voltage regulator board (see Illustration 6–4 for board location).
Pin Number Function 1 Ground 2 (no connection) 3 Composite Out (sample of stereo generator output) 4 FSK In (Normally high; pull low to shift carrier frequency approximately 7.5 kHz. Connect to open collector or relay contacts of user-supplied FSK keyer.) 5 /Auto Carrier Off (Pull low to enable automatic turnoff of carrier with program failure.) 6 Meter Battery (unregulated DC volts; 5 volts = 50 VDC) 7 Meter RF Watts (1 volt = 100 watts) 8 Meter PA Volts (5 volts = 50 VDC) 9 /Ext.
Section 3—Operation This section provides general operating parameters of your transmitter and a detailed description of its front panel display.
3.1 Initial Power-up Procedures These steps summarize the operating procedures you should use for the initial operation of the transmitter. More detailed information follows. CAUTION Possible equipment damage! Before operating the transmitter for the first time, check for the proper AC line voltage setting and frequency selection as described in sections 2.3 and 2.4. 1. Turn on the main power switch.
8. Check the following parameters on the front panel multimeter: a. RF Power should be 500–550 watts. b. SWR should be less than 1.25 (A reading greater than 1.25 indicates an antenna mismatch). c. ALC should be between 4.00 and 6.00 volts. d. PA DC Volts should be 46–56 volts. (Varies with antenna match, power, and frequency.) e. PA DC Amperes should be 12–16 amps. (Varies with antenna match, power, and frequency.) f. PA Temperature should initially read 20–35 degrees C (room temperature).
3.2 Power Switches 3.2.1 DC Breaker The DC breaker, on the rear panel, must be on (up) for transmitter operation, even when using AC power. Electrically, the DC breaker is located immediately after diodes which isolate the DC and AC power supplies. 3.2.2 Power Switch The main on/off power switch controls both the 120/240 VAC and the DC battery power input. 3.2.
3.3 Front Panel Bar-Dot Displays Bar-dot LEDs show audio input levels, wideband and highband audio gain control, and modulation percentage. Resolution for the gain control and modulation displays is increased over a conventional bar-graph display using dither enhancement which modulates the brightness of the LED to give the effect of a fade from dot to dot. (See section 4.7.) 3.3.
3.4 Input Gain Switches The “+6 dB” and “+12 dB” slide switches set audio input sensitivity according to the following table. Nominal Input Sensitivity +10 dBm +4 dBm -2 dBm -8 dBm Switches +6 dB +12 dB Down Down Up Down Down Up Up Up Table 3–1 Input Gain Switches Find, experimentally, the combination of Input Gain switch settings that will bring the Wideband gain-reduction indicator to mid scale for “normal” level program material.
3.7 RF Output Control Set this control for the desired output power level. Preferably, set the power with an external RF wattmeter connected in the coaxial line to the antenna. You may also use the RF power reading on the digital multimeter. The control sets the RF output voltage. Actual RF output power varies as the approximate square of the relative setting of the control. For example, a setting of “50” is approximately 1/4 full power.
ALC—DC gain control bias used to regulate PA supply voltage. With the PA power supply at full output voltage, ALC will read about 6.0 volts. When the RF output is being regulated by the RF power control circuit, this voltage will be reduced, typically reading 4 to 5.5 volts. The ALC voltage will be reduced during PA DC overcurrent, SWR, or LOCK fault conditions. PA DC Volts—Supply voltage of the RF power amplifier. PA DC Amps—Transistor drain current for the RF power amplifier.
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4.2 Audio Processor Circuit Board The audio processor board provides the audio control functions of a compressor, limiter, and expander. Illustration 6–5 and accompanying schematic may be useful to you during this discussion.
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Stereo Generator 10 2 High Band RF Power High Expand 2 Compress SWR 20 ALC PA DC Volts Wide Band PA DC Amps -6 SWR Over Lock 100 Input 90 PA DC 80 PA Temp 70 60 PA Temperature Supply DC Volts -12 Modulation Fault Audio Input +6 dB +12 dB Carrier Power 50 Stereo 40 Voltmeter 30 -18 20 Low Input Gain Mono Processing RF Output ® Pilot FM500 FM BROADCAST TRANSMITTER Illustration 4–3 Stereo Generator Board each with a Q of 5.
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U6 is programmed with the four or five rotary switches. The binary output of the 0.1 MHz switch programs the “A” counter directly. BCD data from the 100’s, tens, and units rotary switches is converted to binary data by U3 to set the “N” counter. An optional fifth digit rotary switch for 10kHz spacing is available. U5C is a differential amplifier and filter for the error signal.
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The DC voltage setpoint for U404A (reflected RF voltage) is one-fifth that of U404C (forward RF voltage). This ratio corresponds to an SWR of 1.5:1 [(1+.2)/(1–.2)=1.5]. The U405 inverters drive the front panel fault indicators. To get a direct reading of SWR, the reference input of the digital panel meter is fed from a voltage proportional to the forward-minus-reflected RF voltage, while forward-plus-reflected is fed to the digital panel meter input. The panel meter provides the divide function.
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4.8 Voltage Regulator Circuit Board The voltage regulator board is the longer of two boards mounted under the chassis toward the front of the unit. It has switch-mode voltage regulators to provide +12, –12, and 24 volts. It also contains the program detection and automatic carrier control circuits. Illustration 6–11 and accompanying schematic complement this discussion. U703E and U703F convert a 38 kHz sine wave from the stereo generator into a synchronization pulse.
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4.11 RF Amplifier The two RF power amplifier modules are mounted on a combiner board, heat sink, slide rail assembly which slides into the main chassis at the rear, and is fastened to the back panel with six screws. RF power, DC power, and control voltages enter the PA assembly through a 72–pin edge connector that it slides into at the front of the chassis. The amplifier is built around two Phillips BLF278, dual-power MOSFETs rated for 50 volts DC and a maximum power of about 300 watts.
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RF IN Receiver Module (option) Stereo Generator 10 2 High Band RF Power High Expand 2 Compress SWR 20 ALC PA DC Volts Wide Band PA DC Amps -6 SWR Over Lock 100 Input 90 PA DC 80 PA Temp 70 60 PA Temperature Supply DC Volts -12 Modulation Fault Audio Input +6 dB +12 dB Carrier Power 50 Stereo 40 Voltmeter 30 -18 20 Low Input Gain Mono Processing ® RF Output Pilot FM500 FM BROADCAST TRANSMITTER Illustration 4–6 Receiver Board (optional) Generally, the voltage i
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Section 5—Adjustments and Tests This section describes procedures for (1) advanced users who may be interested in customizing or optimizing the performance of the transmitter and (2) service personnel who want to return the transmitter to operational status following a maintenance procedure.
5.1 Audio Processor Adjustments 5.1.1 Pre-Emphasis Selection Select the pre-emphasis curve (75 µsec, 50 µsec, 25 µsec, or Flat) by jumpering the appropriate pins of header JP1 on the audio processor board. (See section 2.9.) If you change the pre-emphasis, change the de-emphasis jumpers, JP203 and JP204 on the Stereo Generator board, to match. (See section 2.8.) 5.1.
5.2 Stereo Generator Adjustments 5.2.1 Separation Feed a 400 Hz sine wave into one channel for at least 70% modulation. Observe the classic single-channel composite stereo waveform at TP1 on the RF Exciter circuit board. Adjust the Separation control for a straight centerline. Since proper adjustment of this control coincides with best stereo separation, use an FM monitor to make or confirm the adjustment. 5.2.
5.3 Frequency Synthesizer Adjustments 5.3.1 Frequency (Channel) Selection Refer to section 2.3. 5.3.2 Modulation Compensator Refer to section 2.3. 5.3.3 Frequency Measurement and Adjustment Next to the 10.24–MHz crystal on the RF Exciter board is a 1–11 pF piston trimmer capacitor (C3). Use C3 to set the frequency of the 10.24–MHz crystal while observing the output frequency of the synthesizer. Use one of these methods for checking frequency: ❑ Use an FM frequency monitor.
5.4 Metering Board Adjustments 5.4.1 Power Calibrate While looking at RF Power on the digital panel meter, set the Power Calibrate trim potentiometer to agree with an external RF power meter. 5.4.2 Power Set With the front panel RF Output control fully clockwise, adjust the Power Set trim pot to 10% more than the rated power (33 W for FM30, 110 W for FM100, 275 W for FM250, 550 W for FM500) as indicated on an accurate external watt meter.
5.5 Motherboard Adjustments For Normal-Bypass switch setting, see section 2.10. 5.6 Display Modulation Calibration The Modulation Calibrate trim pot sets the sensitivity of the front panel Modulation bar graph display. This adjustment may be made only after the Output trim pot on the Stereo Generator board has been set. (See section 5.2.4.) 1. Set the Stereo-Mono switch to Mono. 2. Feed a sine wave source of about 2.
5.9 Performance Verification Measure the following parameters to receive a comprehensive characterization of transmitter performance: ❑ Carrier frequency ❑ RF output power ❑ RF bandwidth and RF harmonics (see section 5.
5.10 Carrier Frequency Carrier frequency is measured at the output frequency with a frequency monitor or suitable frequency counter. To adjust frequency, see section 5.3.3. (FCC tolerance +/– 2000 Hz per FCC Part 73.1540 and 73.1545.) 5.11 Output Power The output power reading on the front panel display should be 90–105% of the actual value. For a more precise measurement, use a watt meter in the RF output line. See sections 5.4.1 and 5.4.2 for setting power. 5.
5.14 Audio Frequency Response For the response tests, take the readings from an FM modulation monitor. Make audio frequency response measurements for left and right channels at frequencies of 50 Hz, 100 Hz, 400 Hz, 1 kHz, 5 kHz, 10 kHz, and 15 kHz. See sections 5.9.1 and 5.9.2. 5.15 Audio Distortion Make distortion measurements from the de-emphasized output of an FM modulation monitor.
5.19.1 Main Channel Into Sub Feed the left and right channels in phase with audio (L+R) at 50 Hz, 100 Hz, 400 Hz, 1 kHz, 5 kHz, 10 kHz, and 15 kHz at 100% modulation, while observing the stereo subcarrier (L-R) level on an FM modulation monitor. 5.19.2 Sub Channel Into Main Feed the audio into the left and right channel as above, with the exception of reversing the polarity of the audio of one channel (L-R input). Using the frequencies of 5.19.
Section 6—Reference Drawings The illustrations in this section may be useful for making adjustments, taking measurements, troubleshooting, or understanding the circuitry of your transmitter.
6.
RF Exciter Stereo Generator Low-pass Filter Metering Audio Processor 10 2 High Band RF Power High Expand 2 Compress SWR 20 ALC PA DC Volts Wide Band PA DC Amps -6 SWR Over Lock 100 Input 90 PA DC 80 PA Temp 70 60 PA Temperature Supply DC Volts -12 Modulation Fault Audio Input +6 dB +12 dB Carrier Power 50 Stereo 40 Voltmeter 30 -18 20 Low Input Gain Mono Processing RF Output Pilot FM500 ® FM BROADCAST TRANSMITTER Illustration 6–3 Chassis Top View Power Amp Fa
6.
R9 1K L VU L IN1 R4 24.9K 1 C3 1.0 R2 1K R6 24.9K 1 +12V C1 100PF L IN2 R8 30.1K 1 C4 1.0 L LP2 7 5 X 3 Y 16 8 20K R IN1 C15 1.0 R40 1K R42 24.9K R IN2 C16 1.0 R41 1K 2 R43 24.9K 8 C18 .047 2 U4A TL072 1 3 7 4 3 7 9 4 1 C14 100PF R45 24.9K U2B TL072 R33 10K 2 U6 13 12 -12V 10 11 D8 R58 11.3K 1 3 PRE-EMP. R123 50K 11 3 R88 10M -5VDC at 0DB GR 4.1V at 20 DB GR 2 IN U17 4 GND C38 1.0 5 TRM +5V C46 0.1 R121 10.0K 1 R122 100 VSS -5V C39 1.
Illustration 6–6 Stereo Generator Board 6–6 FM500 User's Manual
+12V R54 24.9K 1% EXT RTN R55 24.9K C26 1.0 EXTERNAL COMPOSIT IN (3.5V P-P for 75KHz) EXT IN 8 2 R56 24.9K 1% 4 R57 24.9K C5 .0027 POLY 15.2 KHz LOW-PASS FILTER (8th ORDER ELLIPTICAL) 1 2 3 4 5 6 7 LPIN L +6V U1 3 R7 3.65K 1% -6V R1 330 R38 1M 2 8 R5 1K R12 10.0K 1% U3A TL072 1 3 C6 1030PF R9 2K 1% +12V 4 R6 499 1% LPOUT L C1 .0027 POLY C4 0 OHM +12V 2 14 13 12 11 10 9 8 D4 C3 100PF R3 0 OHM JP1 1 INPUT L LTC1064-1 D3 C27 1.0 -12V (3.5V P-P for 7.
SEE NOTE 10 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. 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. M200440PT-A.
1 2 3 4 5 DWG. NO. 6 REV. 200440-SCH A 8 9 E . C . N. 10 11 REVISION HISTORY DESCRIPTION REV 12 DATE DWN 1 FOR PROTOTYPE 01-04-02 DW 2 MODIFIED PER MIKE SENEKI 02-06-02 DW 3 CHG'D R18 PER EAD MRH01. R18 WAS 91K OHM. U5 WAS C 6900-5 06-24-02 DW 246 A-G 4 R8 WAS 1.0K OHM. 05-23-03 DW 277 A PRODUCTION RELEASE 01-29-04 DW H APPROVALS CHK CM PE H DW DP 88-108 MHZ +8V +12V R24 150 +12V 2 MAR-6 C7 .
D 8169-1 Illustration 6–8 RF Metering Board (Add 400 to component designators for schematic reference) 6–10 FM500 User's Manual
+12V PAV J2-4 C401 .01 R406 100K 1 Parts not loaded: 8 2 +5.00V U2 1 J4-3 REM PADCV 1.00V = 10VDC 3 C403, 404 DZ401 R402, 403, 404 Q401, 402 U401 LB401 R401 1N4148 D406 R409 100 4 -12V R410 100 5 (Jumper under board) C406 .01 R405 2.49K 1 J402 12 13 R416 100K R425 1M U405F 74HC14 U3 3 50mv per degree C. R422 75k R420 100K 1 C407 .
6 - 12 FM30/FM100/FM250 User's Manual
DWG. NO. 1 2 3 4 REV. 1 201207-SCH 5 6 7 8 9 5 E . C . N. HD7 FAN FAN+12V ALC / METERING HEADER 2 .156 H RF EXCITER U2 2 3 J2 J1 HD42 1 2 3 4 5 6 7 8 9 10 11 12 HEADER 12 +5.00V 1K HD31 HEADER 5 x 2 +12V DATE DWN 02-05-05 DW PE DW Vin NC GND 7 2 6 3 TRM TL072 1 U3A -12V +5.00V Z9 R43 OPEN 100 C51 5 H C52 .01 C50 1.0 +12V 8 C54 1.0 1.
Jumper FMA "E" Z1 Z2 Z3 Z4 Z5 Z6 Z7 Z8 Z9 Z10 Z11 Z12 Z13 Z14 Z15 Z16 Z17 Z18 Z19 Z20 Z21 Z22 Z23 Z24 Z25 Z26 Z27 Z28 Z29 Z30 Z31 Z32 Z33 JMP1 JMP2 Short Short Open Open Open Open Open Open Short Short Short Short Short Short Open Open Open Open Open Open Open Open Short Short Short Short Short Short Short Short Open Short Short Open Open FMA "T" 50K input Short Short Open Open Open Open Open Open Open Open Open Open Open Open Open Open Open Open Open Open Open Open Short Short Short Short Short Short Sho
R27 D 8167-5 Illustration 6–10 Display Board (Add 600 to component designators for schematic reference) 6–14 FM500 User's Manual
U602 LM3915 JP601 +12V +12V R601 68K L VU R602 100K 8 R604 1.2K D601 1N4148 8 2 3 4 U601A TL072 7 6 5.00V R603 1K 1 C601 1.0UF 9 5 C602 1.0UF D602 1N4148 4 3 +12V 2 -12V 1 MODE DL601-610 +5V RADJ L9 ROUT L8 DHI L7 IN L6 DLO L5 V+ L4 V- L3 L1 10 L10 11 YEL 12 G G DL621-625 16 1 8 GRN 18 L 1 C603 1.0UF R VU R607 68K D603 1N4148 6 7 7 6 5.00V R609 1K 5 U601B TL072 9 8 R610 1.2K 5 C604 1.
Reference Drawings 6 - 17
CARR SW R701 4.7K U703C R702 10K /CARRIER OFF 5 6 ELKHART, IN. 46517 R723 1K D701 1N4148 U703A R704 10K /AUTO CARRIER 1 3 2 +6V +12V R705 91K 4 D703 1N6263 2 1 1 1 C701 .01 11 R716 10K 7 12 5 U701B TL074 R715 2.2K R714 220 -12V R710 75K 1 13 R711 100K 14 DL701 GREEN DL702 RED C704 .001 R712 1M 7 5 4 6 14 13 15 1 2 3 Q4 Q5 Q6 RST Q7 Q8 Q9 Q10 Q12 Q13 Q14 R721 24.9K 1 VDD C705 1.
Illustration 6–12 Power Regulator Board 6–18 FM500 User's Manual
1 2 3 4 5 6 REVISION HISTORY DESCRIPTION ON CHASSIS E . C . N. BATTERY ~ - DC INPUT + C1001 0.
R19 R20 Illustration 6–13 Power Amplifier (Add 1100 to component designators for schematic reference) 6–20 FM500 User's Manual
C909 L904 L903 23.2uH U900 10.4uH R900 MRF 137 680PF C908 27PF C907 5PF C910 36PF THESE DRAWINGS AND SPECIFICATIONS ARE THE PROPERTY OF CROWN INTERNATIONAL, INC. AND SHALL NOT BE REPRODUCED, COPIED, OR USED AS THE BASIS FOR THE MANUFACTURE OR SALE OF APPARATUS OR DEVICES WITHOUT PERMISSION. C906 36PF C905 10PF 9 C903 0.01 8 CA2832 7 5 3 2 CROWN INTERNATIONAL, INC. 1718 WEST MISHAWAKA ROAD J2 R900 51 DRAWN JFL C900 RF DRIVER BD SCALE R901 51 0.01 SUPERSEDES NONE EE E.C.
P10421-9 Illustration 6–14 RF Output Filter (Add 1200 to component designators for schematic reference) 6–22 FM500 User's Manual
(455MHz) (195MHz) (176MHz) (252MHz) C1202 1.35PF C1204 7.1PF C1206 9.3PF C1208 5.13PF C1211 47PF NP0 R1202 * 75 R1203 10 RF OUT RF IN L1202 90.5NH L1201 250NH C1201 15.4PF C1201A 10PF L1203 94.1NH C1203 40.9PF C1217 3.5PF C1205 38.9PF C1209 14.1PF C1207 37.7PF C1209A 2PF R1201 100 D1202 1N6263 C1212 47PF NP0 D1201 1N6263 Approx. 7V RMS with 200W RF in. R1209 1K R1206 1K RF MONITOR C1213 .001 INDUCTORS I.D. TURNS L1201 0.25" 0.7" #17 L1202 0.5" 3 0.6" #12 L1203 0.
Reference Drawings 6 - 25
1 2 3 4 5 E . C . N. REV 264 M 279 316 361 ADDED TO PWB (200922-PWB-D IN LOCATION SHOWN, AND DEPICTED ON COMPONENT MAP. F C23 6 C24 7 REVISION HISTORY DESCRIPTION 8 APPROVALS CHK CM DATE DWN PRODUCTION RELEASE 12-10-03 DW DW DP PE N XU1 WAS 200479-TERM-10 01-29-04 DW DW MH O PWB CHG'D TO REV. C 06-14-04 DW DW DP P PWB CHG'D TO REV. D 03-22-05 DW DW DP F .01 .
Mother Board J 403 6 5 4 3 2 1 HD561 Ribbon V+ Temp Gnd HD 502 HD701 HD503 3 2 1 FM500 Chassis Wiring C.
Illustration 6–16 Receiver Board Reference Drawings 6–27
Receiver 6–28 FM500 User's Manual
Section 7—Service and Support We understand that you may need various levels of support or that the product could require servicing at some point in time. This section provides information for both of these scenarios.
7.1 Service The product warranty (see opposite page) outlines our responsibility for defective products. Before returning a product for repair or replacement (our choice), call our Customer Service department using the following telephone number: (866) 262-8917 Our Customer Service Representative will give you further instructions regarding the return of your product. Use the original shipping carton or a new one obtained from Crown.
Three-Year Limited Warranty North America Only SUMMARY OF WARRANTY We, Crown Broadcast, a business unit of International Radio and Electronics Company, Inc.
Notes: 7–4 FM500 User's Manual
Factory Service Instructions To obtain factory service, complete the bottom half of this page, include it with the unit, and ship to: International Radio 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 for ground UPS shipments from anywhere in the continental U.S. and Federal Express Second Day service from Hawaii and Alaska to the factory and back to you.
Appendix Transmitter Output Efficiency FM500 User's Manual Appendix–1
Transmitter efficiency output RF Power Output Efficiency-FM500 PADC Volts PADC Amps RF Power Efficiency 51.3 13.91 550 77% 48.3 13.29 500 78% 45.5 12.74 450 77% 42.7 12.14 400 77% 39.4 11.46 350 78% 36.0 10.68 300 78% 33.0 10.00 250 76% 29.6 9.25 200 73% 25.4 8.28 150 71% 21.1 7.29 100 65% Power measurements were made at 97.1 MHz. Voltage and current measurements were taken from the unit's built-in metering.
A B C Glossary The following pages define terms and abbreviations used throughout this manual.
A B C AF Audio Frequency; the frequencies between 20 Hz and 20 kHz in the electromagnetic spectrum. ALC Automatic Level Control AM Amplitude Modulation; the process of impressing information on a radio-frequency signal by varying its amplitude. bandwidth The range of frequencies available for signalling. BCD Binary-Coded Decimal; a digital system that uses binary codes to represent decimal digits.
exciter FET (1) A circuit that supplies the initial oscillator used in the driver stage. (2) A transmitter configuration which excludes stereo generation and audio processing. Field-Effect Transistor frequency synthesizer A circuit that generates precise frequency signals by means of a single crystal oscillator in conjunction with frequency dividers and multipliers. FM Frequency Modulation; the process of impressing information on a radio signal by varying its frequency.
A B C PAI Power Amplifier Current PAV Power Amplifier Voltage pilot A 19–kHz signal used for stereo transmissions. pre-emphasis The deliberate accentuation of the higher audio frequencies; made possible by a high-pass filter. processing The procedure and/or circuits used to modify incoming audio to make it suitable for transmission. receiver An option which adds incoming RF capability to an existing transmitter. See also "Translator.
SWR Standing-Wave Ratio; on a transmission line, the ratio of the maximum voltage to the minimum voltage or maximum current to the minimum current; also the ratio of load impedance to intended (50 ohms) load impedance. THD Total Harmonic Distortion translator A transmitter designed to internally change an FM signal from one frequency to another for retransmission. Used in conjunction with terrestrial-fed networks.
Index Symbols 19–kHz level adjustment 5–3 phase adjustment 5–3 A AC.
adjustment 5–3 connectors audio input 2–10 audio monitoring 2–12 composite in 2–11 remote I/O 2–11, 2–13 RF input 2–9 RF output 2–9 RF output monitoring 2–9 SCA In 2–11 XLR 2–11, 4–3 cooling fan 3–2 control 4–9 coverage area 1–4 crosstalk 1–7 measurements 5–9 current limit PA 5–5 D DC.
L labels 1–10 LEDs 3–5, 4–10 line voltage 2–3 lock status 4–7 lock fault 3–8 M metering 1–2 circuit description 4–8 metering board adjustments 5–5 location 4–8, 4–15 reference drawings 10 modulation 2–11, 3–5, 5–3, 5–7, 5–8 calibration 5–6 compensator 2–6 display 3–5 percentage 3–5, 5–9 monitor audio 2–12, 4–5 mono operation 2–11, 3–6 motherboard circuit description 4–9 reference drawings 12 multimeter 3–7 front panel 3–3 N networks satellite-fed 1–6 terrestrial-fed 1–5 noise 1–7, 3–8 measurements 5–9 O
R (continued) RF amplifier 4–13 bias set 5–6 bandwidth 1–8, 5–8 exciter 2–5, 2–11 board location 2–5, 4–6 circuit description 4–6 reference drawings 8 input 1–5, 2–9 output 1–2, 1–5, 1–7, 3–3, 3–7 impedance 1–7 output filter 4–14, 22 tuning 2–7 S safety 1–10 satellator transmitter use 1–6 SCA 1–5 input connection 2–11 sensitivity monaural 1–9 stereo 1–9 separation stereo 1–7 stereo generator 5–3 service warranty 7–3 Service Instructions 7–5 specifications receiver 1–9 transmitter 1–7 stand-alone transmitte
