©2003 Crown Broadcast, a division of International Radio and Electronics, Inc. 25166 Leer Drive, Elkhart, Indiana, 46514-5425 U.S.A.
Rev. 1.0 Revision Print Date Rev. 1.0 January 2003 ©2002, 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 any form by any means without the written permission of International Radio and Electronics, Inc. Printed in U.S.A.
Rev. 1.0 Table of Contents Table of Contents iii Section 1—Getting Acquainted 1.1 Your Transmitter .........................................................................................1-2 1.2 Applications and Options.............................................................................1-3 1.2.1 Stand-Alone.............................................................................................1-4 1.2.2 Backup ..................................................................................
Rev. 1.0 3.3.1 Passwords...............................................................................................3-4 3.3.2 Main Function List...................................................................................3-4 3.3.3 Readings Function List ............................................................................3-5 3.3.4 Settings Function List..............................................................................3-6 3.3.5 Factory Setting Functions...........................
Rev. 1.0 I INFORMATION This section provides a general description of the FMX30, FMX100, and FMX250 transmitters and introduces you to safety conventions used within this document. Review this material before installing or operating the transmitter.
I Rev. 1.0 The FMX30, FMX100, and FMX250 are members of a family of FM stereo broadcast transmitters. Crown transmitters are known for their integration, ease-of-use, and reliability. The integration 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.
Rev. 1.0 Crown transmitters are designed for versatility in applications. They have been used as stand-alone and backup transmitters and in booster, translator, satellator, and nearcast 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 Rev. 1.0 1.2.1 Stand-Alone In the standard configuration, the FMX30, FMX100, and FMX250 are ideal standalone transmitters. When you add an audio source (monaural, L/R stereo, or composite signal), an antenna, and AC or DC 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.
Rev. 1.0 1.2.5 Translator The FMX30R receiver option replaces the audio processor and stereo generator boards with a receiver module. This added feature makes Crown transmitters 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 Rev. 1.0 1.2.6 Satellator Crown transmitters include automatic call sign or operating frequency transmission in a Morse code style. This feature 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 built-in FSK IDer does the rest—shifting the frequency to comply with FCC requirements and in a manner that is unnoticeable to the listener. 1.2.
Rev. 1.0 = Frequency Range 87.9 -107.9 MHz RF Power Output FMX30 (VSWR 1.
I Rev. 1.
Rev. 1.0 Monaural Sensitivity (demodulated, de-emphasized) 3.5µV for signal-to-noise > 50 dB 12.6µV for signal-to-noise > 60 dB Stereo Sensitivity (19–kHz pilot frequency added) 2.
I Rev. 1.0 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.
This section provides important guidelines for installing your transmitter. Review this information carefully for proper installation.
Rev. 1.0 CAUTION Possible equipment damage! Before operating the transmitter for the first time, check for the proper AC line voltage setting and frequency described in Section 2.2, Power Connections and Section 2.3, Frequency (Channel) Selection. 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.
Rev. 1.
Rev. 1.0 2.2.2 Fuses The fuse holders are located in the power connector assembly just below the voltage selector. : Illustration 2–3 Fuse Holder For 100 to 120 VAC operation, use the fuse installed at the factory. For 220 to 240 VAC operation, use the slow-blow fuse located in a hardware kit within the transmitter packaging. Consult the following table: Transmitter FMX30 FMX100 FMX250 Input Power 100-120 V 220-240 V 100-120 V 220-240 V 100-120 V 220-240 V Fuse 3A 1.5A 6.3 4A 12.5A 6.
Rev. 1.0 The transmitting frequency for Crown FMX series transmitters is set from a front panel control. However, you must set the modulation compensator for the operating frequency. 2.3.1 Modulation Compensator The Modulation trim-potentiometer, (see Section 2–4, Modulation Compensator Settings), compensates for slight variations in deviation sensitivity with frequency.
Rev. 1.0 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). Receiver Module Frequency Selection Switches Illustration 2–5 Receiver Module Switches 2. Use Table 2-2, Receiver Frequency Selection, to set the switches for the desired incoming frequency. After setting the frequency, return to Section 2.3.
Rev. 1.0 Freq 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 SW1 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 SW2 Freq 0 92.9 0 93.0 1 93.1 1 93.2 2 93.3 2 93.4 3 93.5 3 93.6 4 93.7 4 93.8 5 93.9 5 94.0 6 94.1 6 94.2 7 94.3 7 94.4 8 94.5 8 94.6 9 94.
Rev. 1.0 Connect the RF load, 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.
Rev. 1.0 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.
Rev. 1.0 L IN1 C3 1.0 R2 1K R4 24.9K 1 R6 24.9K 1 +12V Right R504 1K J502 3 2 1 XLR 5 6 7 8 A501 J501 3 2 1 R501 1K HI LO GND 2 3 1 XLR CON. R3 1K C4 1.0 C504 220PF C2 R40 1K C501 220PF C502 220PF C13 100PF R41 1K R8 30.1K 1 8 R5 24.9K 1 100PF R502 1K DIP8 XLR Left R503 1K C503 220PF 4 3 2 1 C1 100PF 2 1 3 U1A TL072 4 R7 24.9K 1 -12V R42 C15 24.9K 1.0 R43 C16 24.9K 1.0 +12V 2 1 3 4 C14 100PF R45 24.9K R44 24.9K 8 R47 30.
Rev. 1.0 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.
Rev. 1.0 SC A IN COMPOSITE IN RIGHT MONITOR R LEFT/MONO L REMOTE I/O 1 2 3 B A T T E R Y + CIRCUIT BREAKER Composite In BNC Connector OFF – 36 VDC Audio Monitor Jacks Illustration 2–10 Composite In and 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.
Rev. 1.0 You can enable an automatic turn-off of the carrier in the event of program failure. To enable this option, selecte a setting from Table 2-3, Fault Time-out Values. The time between program failure and carrier turn-off is set by a jumper (JP701) on the voltage regulator board. (See Illustration 2–11, Chassis Bottom View, for board location).
Rev. 1.0 Remote control and remote metering of the transmitter is made possible through a 15–pin, D-sub connector on the rear panel. (No connections are required for normal operation.) Remote I/O SCA IN RIGH T MONITOR COMPOSIT E IN R LEFT/MONO L REMOTE I/O 1 2 3 + CIRCUIT BREAKER B A T T E R Y OFF – 36 VDC Illustration 2–12 Remote I/O Connector Table 2-4, Remote I/O Connector, summarizes the Remote I/O pin connections.
Rev. 1.0 Pin Number Function 1 Ground 2 (no connection) 3 Composite Out (sample of stereo generator output) 4 FSK In (Normal ly 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 l ow to enable automatic turnoff of carrier with program failure.
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This section provides general operating parameters of your transmitter and a detailed description of its front panel display and controls.
Rev. 1.0 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 Section 2.2 and 2.3. Before operating the transmitter, take time to become familiar with the controls and indicators. 3.2.
Rev. 1.0 Carrier SwitchThis switch controls power to the RF amplifiers and supplies a logic high to the voltage regulator board, which enables the supply for the RF driver. In addition, the Carrier Switch controls the operating voltage needed by the switching power regulator. A “Lock Fault” or a low pin 12 (/Carrier Off) on the Remote I/O connector will hold the carrier off. (See Section 2.
Rev. 1.0 3.2.2 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.
Rev. 1.0 When initially powered, the main function list is displayed. Use the control knob to select one of the main functions. When a main function is selected, the main function list is replaced with a sub function list. 3.3.3 Readings Function List Readings functions are for operators to use to verify proper operation of the transmitter. These functions are not password protected. Readings function list has two main lists. The Primary list is one which most of the common readings are taken.
Rev. 1.0 DPC Version : Software version of the Digital Power Control. MDC Version : Software version of the metering digital control. RMS Version : Version of software installed in the optional Remote Management System. Back : 3.3.4 Returns to previous menu function list. Settings Function List Settings functions change operating parameters and alarm limits. A password is required for access to Settings functions.
Rev. 1.0 New password : Change the Settings password. RMS Board : Select RMS option ON/OFF RMS Menu : Select this menu to change the three different phone numbers stored in the RMS unit. Phone numbers are edited directly by selecting the appropriate number. Phone # 1 will be the first number the RMS will call when there is a fault. Phone # 2 is the second in case # 1 doesn’t answer. Phone # 3 is the last and then repeats to # 1. Factory reset : Returns user settings to factory settings.
Rev. 1.0 These steps summarize the operating procedures you should use for the initial operation of the transmitter 3.4.1 Apply Power 1. Turn on the DC breaker. 2. Turn on the main power switch. 3. Verify the following: a. The bottom cooling fan runs continuously. b. The indicator ring flashes orange for approximately 10 seconds, then goes dark. 3.4.2 Enter Initial Settings 1. Choose [Setting] then [Primary] then [Tx freq] to set transmitting frequency. Choose [back] when finished. 2.
Rev. 1.0 PS DC V : Supply DC volts varies by model: 45 volts with the carrier on and 50 volts with the carrier off for both the FMX30 and FMX100 products. FMX250, the readings should be 65 volts with the carrier on and 75 volts with carrier off.Voltmeter should be reading 0.0.
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ue n ha 'e n ta ci ue n ha ta ci ue 'e n n ha 'e n ta ci ta ci 'e n ta ci ta ci ue n ha 'e n ta ci This section discusses the basic circuit principles upon which the transmitter functions. This information is not needed for day-today operation of the transmitter but may be useful in understanding basic transmitter functions.
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Rev. 1.0 The audio processor board (Illustration 4-2) performs five functions: • Balanced input amplifier • Gain selection • Low-pass filter • Signal compression, limiting and expansion • Pre-emphasis Each of these functions are discussed in the following section. Audio Processor Illustration 4-2 Audio Processor Board 4.2.1 Balanced Input Audio input from the rear-panel, XLR connectors route to differential-input amplifiers and then to a buffer amplifiers.
Rev. 1.0 The RC networks in the processor use three different time constants to cover a variety of signal conditions. Short, transient audio peaks produce quick gain reduction with quick recovery, while long term level trends produce slower gain reduction, with slow recovery. Highband processing shifts the pre-emphasis curve rather than affecting overall gain. The amount of short-term expansion and gain reduction is adjusted by control R650, located on the front panel display board.
Rev. 1.0 4.3.2 Stereo Generator The 19 and 38–kHz subcarriers are digitally synthesized from a master 7.6 MHz crystal oscillator. The 1.52 MHz clock signal used by the low-pass filter is also derived from the 7.6 MHz master oscillator. Stereo signals are generated by a four-quadrant, analog multiplier. The output of multiplier is the product of 38 kHz applied to the “X” input and the difference of left and right audio (L-R signal) applied to the “Y” input.
Rev. 1.0 The RF Exciter Circuit board is also known as the Frequency Synthesizer board. The entire component side of the board is a ground plane. RF Exciter Board Illustration 4-4 RF Exciter Board The frequency-synthesizer consists of the following: • • • • A voltage-controlled oscillator A frequency synthesizer integrated circuit.
Rev. 1.0 The frequency synthesizer also produces a lock signal. This signal is inverted and buffered to produce both lock and unlock status signals for use in other parts of the transmitter. An FSK signal (used for automatic identification of FM repeaters) shifts the frequencies of the 10.24–MHz crystal reference and the VCO. With keying, diodes in the in the oscillator are reverse biased, increasing the crystal reference frequency. At the same time, current through R358 increases the VCO frequency.
Rev. 1.0 The transmitter is controlled from a single, push-and-turn control knob. LEDs illuminate the ring around the knob to display start-up, on-air or fault conditions. The motherboard is the large board in the upper chassis interconnecting the audio processor, stereo generator, RF exciter, and metering boards. The motherboard provides the interconnections for these boards, eliminating the need for a wiring harness, and provides input/output filtering.
Rev. 1.0 For delay times, see Table 4-1, Program Delay Settings. The times are proportional to the value of R721; times can be doubled by doubling the value of R721. JP701 Jumper 3 and 4 5 and 6 7 and 8 Delay 2–minute 4–minute 8–minute Table 4-1 Program Delay Settings The power regulator board is the shorter of two boards mounted under the chassis toward the front of the unit.
Rev. 1.0 Input transformer is made up of two printed circuit boards. A four-turn primary board is separated from a one-turn secondary by a thin dielectric film. Multiple resisters provided damping. A trim pot sets the bias. The output transformer has a one-turn primary on top of the circuit board and a two-turn secondary underneath. Inductors provide power line filtering. The AC power supply components, as well as the bridge rectifier and main filter capacitor are mounted on the chassis.
Rev. 1.0 The RF low-pass filter/reflectometer are located in the right-hand compartment on the top of the chassis. A ninth-order, elliptic, low-pass filter attenuates harmonics generated in the power amplifier. The capacitors for the filter are circuit board pads. The reflectometer uses printed circuit board traces for micro-strip transmission lines.
Rev. 1.0 the synthesizer to the selected frequency to produce an intermediate frequency of 10.7 MHz. The 10.7 MHz IF frequency comes out of the tuner module and is coupled into the first filter FL1; passes through FL1 and into the IF decoder system. The FL1 filter sets the bandwidth or everything outside of the bandwidth depending on the filter that is selected. It could be a bandwidth of 180 kHz where everything outside of that is filtered out depending on the filter characteristics.
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.
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, Cr own Broadcast, a business unit of Inter nat ional Radio and El ect ronics Company, I nc.
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 Al aska to the factory and back to you.
