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Rev.  1.0

FMX30/FMX100/FMX250 User’s Manual

2—6

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 Table 2-2, Receiver Frequency Selection, to set the switches for the desired

incoming frequency.

After setting the frequency, return to Section 2.3.1, Modulation Compensator, to set
the modulation compensator.

Note: If you requested it, the FSK chip on the RF Exciter Board has been

pre-programmed for your operating frequency. This chip is
replaceable. Should you need to change the location of your
translator, contact Crown Broadcast for a replacement chip with your
new FSK ID.

Replace the top cover before operating the transmitter.

Illustration 2–5 Receiver Module Switches

Receiver
Module

Frequency Selection
Switches

Summary of Contents for FMX100

Page 1: ...2003 Crown Broadcast a division of International Radio and Electronics Inc 25166 Leer Drive Elkhart Indiana 46514 5425 U S A 574 262 8900...

Page 2: ...lication 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 Elect...

Page 3: ...ng Location 2 2 2 2 Power Connections 2 2 2 2 1 AC Line Voltage Setting 2 2 2 2 2 Fuses 2 4 2 3 Frequency Channel Selection 2 5 2 3 1 Modulation Compensator 2 5 2 3 2 RF Tuning Adjustments 2 5 2 4 Rec...

Page 4: ...2 2 Audio Processor 4 3 4 3 Stereo Generator Circuit Board 4 4 4 3 1 Low pass filter 4 4 4 3 2 Stereo Generator 4 5 4 3 3 SCA Input 4 5 4 3 4 Processed Audio 4 5 4 4 RF Exciter Circuit Board 4 6 4 5 D...

Page 5: ...NFORMATION 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 instal...

Page 6: ...ies of transmitters also feature more sophisticated inputs and monitoring connections if needed Reliability is a Crown tradition The first Crown transmitters were designed for rigors of worldwide and...

Page 7: ...can expect The number portion of each name represents the maximum RF output power The FMX250 for example can generate up to 250 watts of RF output power Suffix letters describe the configuration The F...

Page 8: ...ts for those times when AC power is lost 1 2 3 Booster Also in the standard configuration Crown transmitters have been used as booster transmitters Booster applications typically involve certain geogr...

Page 9: ...ansmitters In addition the module supplies a composite output to the RF exciter portion of the transmitter From here the signal is brought to full power by the built in power amplifier for retransmiss...

Page 10: ...shifting the frequency to comply with FCC requirements and in a manner that is unnoticeable to the listener 1 2 7 Nearcasting Some Crown units function as nearcast transmitters Their low power output...

Page 11: ...sec or Flat Audio Response Conforms to 75 sec pre emphasis curve as follows Complete transmitter 0 30 dB 50 Hz 10 kHz 1 0 dB 10 kHz 15 kHz Exciter only 0 25 dB 50 Hz 15 kHz Distortion THD Noise Compl...

Page 12: ...mps required for full output power 36 62 volts 48 volts at 5 amps required for full output power 36 62 volts 72 volts at 8 amps required for full output power Note Note We set voltage and ampere requi...

Page 13: ...emphasized 3 5 V for signal to noise 50 dB 12 6 V for signal to noise 60 dB Stereo Sensitivity 19 kHz pilot frequency added 2 8 V for signal to noise 40 dB 8 V for signal to noise 50 dB 31 V for signa...

Page 14: ...GER represents the most severe hazard alert Extreme bodily harm or death will occur if DANGER guidelines are not followed 1 5 2 Warnings WARNING represents hazards which could result in severe injury...

Page 15: ...Installation 2 1 This section provides important guidelines for installing your transmitter Review this information carefully for proper installation...

Page 16: ...with reduced RF output power see section 1 2 In addition the transmitter isolates the AC and DC sources both can be connected at the same time to provide battery backup in the event of an AC power fa...

Page 17: ...Rev 1 0 Installation 2 3 Illustration 2 1 Removing the Power Connector Cover Illustration 2 2 Selecting an AC Line Voltage 120Vac 120Vac 220Vac 240Vac...

Page 18: ...peration 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 Illustration 2...

Page 19: ...ct settings see Section 5 2 2 Composite Output Replace the top cover before operating the transmitter 2 3 2 RF Tuning Adjustments All the RF stages are broadband to cover the 88 to 108 MHz broadcast b...

Page 20: ...ed incoming frequency After setting the frequency return to Section 2 3 1 Modulation Compensator to set the modulation compensator Note If you requested it the FSK chip on the RF Exciter Board has bee...

Page 21: ...4 100 1 3 D 105 1 5 6 90 2 8 B 95 2 A 4 100 2 B D 105 2 D 6 90 3 0 C 95 3 2 5 100 3 3 E 105 3 5 7 90 4 8 C 95 4 A 5 100 4 B E 105 4 D 7 90 5 0 D 95 5 2 6 100 5 3 F 105 5 5 8 90 6 8 D 95 6 A 6 100 6 B...

Page 22: ...or connection Information gained through this connection can supplement that which is available on the transmitter front panel displays If your transmitter is equipped with the receiver option connect...

Page 23: ...hould be grounded to the shield at the source Audio will then connect to the line going to pin 2 By bringing the audio return line back to the program source the balanced differential input of the tra...

Page 24: ...1 2 3 4 8 7 6 5 A501 DIP8 C503 220PF C502 220PF C504 220PF L IN1 12V 12V C3 1 0 C1 100PF C2 100PF R2 1K R3 1K R4 24 9K 1 R5 24 9K 1 R6 24 9K 1 C4 1 0 R7 24 9K 1 2 3 1 8 4 U1A TL072 R8 30 1K 1 C15 R44...

Page 25: ...ter only E version or when using the T version with composite input it is necessary to use the Composite Input section of the transmitter This will feed composite stereo or mono audio directly to the...

Page 26: ...rder to feed the left and right pre emphasized audio directly to the stereo generator The Normal Bypass slide switch is near the left rear corner of the motherboard If the audio source is already proc...

Page 27: ...r turn off is set by a jumper JP701 on the voltage regulator board See Illustration 2 11 Chassis Bottom View for board location Delay Pins to Jumper 30 seconds 1 2 pins closest to edge 2 minutes 3 4 4...

Page 28: ...h a 15 pin D sub connector on the rear panel No connections are required for normal operation Table 2 4 Remote I O Connector summarizes the Remote I O pin connections Illustration 2 12 Remote I O Conn...

Page 29: ...1 volt 100 watts 8 Meter PA Volts 5 volts 50 VDC 9 Ext Enable Pull low to disable internal stereo generator and enable External Composite Input 10 a 38 kHz Out From stereo generator for power supply s...

Page 30: ...Rev 1 0 FMX30 FMX100 FMX250 User s Manual 2 16...

Page 31: ...Operation 3 1 This section provides general operating parameters of your transmitter and a detailed description of its front panel display and controls...

Page 32: ...etting During program pauses the red Low LED will light Modulation DisplayA 20 segment vertical peak and hold bar graph displays the peak modulation percentage A reading of 100 coincides with 75 kHz d...

Page 33: ...nd parameters Use in conjunction with Main Display Main DisplayThe FMX Main Display is a four line alpha numeric display All critical transmitter parameters controls and alarm settings are displayed o...

Page 34: ...etter use the control knob to move a flashing cursor block over characters in the selected line When the cursor is in position push and release the control knob Then turn the knob to scroll through th...

Page 35: ...ge regulators For battery operation this reading is the battery voltage minus a diode drop Voltmeter Displays the voltage at a test point located on the front edge of the motherboard A test lead conne...

Page 36: ...Selects the transmission mode In Stereo Off feed program audio only to the left channel Although right channel audio will not be transmitted as audio modulation it will affect the audio processing RF...

Page 37: ...ent Choose from the visible list or scroll forward or back to find a specific fault The record of each fault includes Event Date Time Value Clear Removes all faults from log Before actual clearing the...

Page 38: ...meters from the Readings primary list RF Power RF Power varies by model 29 33 watts for the FMX30 95 110 watts for the FMX100 250 275 watts for the FMX250 SWR Standing wave ratio should be less than 1...

Page 39: ...lts 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 c...

Page 40: ...Rev 1 0 FMX30 FMX100 FMX250 User s Manual 3 10...

Page 41: ...ha e n ta ci ta ci ue n ha e n ta ci e n ta ci This section discusses the basic circuit principles upon which the transmitter functions This information is not needed for day to day operation of the...

Page 42: ...Rev 1 0 FMX30 FMX100 FMX250 User s Manual 4 2 Illustration 4 1 Block Diagram...

Page 43: ...The output of the buffer amplifiers drive both the front panel indicators and a low pass filter stage on the Stereo Generator board 4 2 2 Audio Processor The audio processor section provides the foll...

Page 44: ...JP1 Controls R29 and R65 are for making fine adjustments to the pre emphasis curve The stereo generator board Illustration 4 3 generates a composite stereo signal from left and right channel audio inp...

Page 45: ...switch at the input of the stereo generator provides selection of left and right audio for stereo and mono modes In the mono mode right channel audio is disabled and the left channel audio is increase...

Page 46: ...r IC where the signal is divided down to 10 KHz The synthesizer also divides the 10 24 MHz crystal frequency to 10 KHz Differences in the two frequencies appear as an error signal at the output of the...

Page 47: ...trols and display 4 5 1 Metering Boards The metering boards provide four functions Scale operating parameters from various points in the transmitter to a propor tional DC voltage Generate the ALC sign...

Page 48: ...ides 12 12 and 24 volts to the transmitter It also contains the program detection and automatic carrier control circuits The 38 kHz sine wave from the stereo generator is used for a synchronization pu...

Page 49: ...age of 28 volts in the FM30 The circuit board has components for input and output coupling and for power supply filtering The RF Driver assembly is mounted on a 100 mm x 100 mm plate in the under side...

Page 50: ...s Switching in the power entry module configures the power transformer for 100 120 220 or 240 VAC see Section 2 2 Power Connections for switching and fuse information A terminal strip with MOV voltage...

Page 51: ...ed RF signal and converts it to composite audio which is then fed into the exciter board Microprocessor controlled phase lock loop technology ensures the received frequency will not drift and multiple...

Page 52: ...ls go to gain amplifiers and then to the RCA jacks on the back of the transmitter These can be used for off air monitoring of the audio signal Incoming frequency can be monitored from the frequency mo...

Page 53: ...ce and Support 5 1 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 scena...

Page 54: ...e Instructions sheet page 7 5 and include it with your returned product In most instances what you need to know about your product can be found in this manual There are times when you may need more in...

Page 55: ...er must bear the expense of shipping the product between any foreign country and the port of entry in the United States and all taxes duties and other custom s fee s for such foreign shipments HOW TO...

Page 56: ...ight or forward your receipt for shipping charges which we will reimburse We do not cover any charges for shipping outside the U S or any of the expenses involved in clearing customs If you have any q...

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