Crown FM250G User Manual Download Page 14

Rev A

FM250G User’s Manual

I

1—8

1.4

Receiver Specifications

Operating Environment

Temperature (0

o

 C -50

o

 C) 

Humidity (0-80% at 20

o

 C) 

Maximum Altitude (3,000 meters; 9843 
feet)

AC Power

90-264 volts; 650 VA at 120 or 240 volts 
AC

Note:

Note:  We set voltage and ampere requirements to assist you in 
designing your system.  Depending on your operating frequency, 
actual requirements for maximum voltage and current readings are 
10-15% lower than stated.

Regulatory

 Meets CE and TUV requirements

Dimensions

13.5 x 41.9 x 44.5 cm

(5.25 x 16.5 x 17.5 inches)

Weight

13.6 kg (30 lbs) shipping weight

Monaural Sensitivity  
(demodulated, de-emphasized)

3.5 

µ

V for signal-to-noise > 50 dB

12.6 

µ

V for signal-to-noise > 60 dB

Stereo Sensitivity 
(19–kHz pilot frequency added)

2.8 

µ

V for signal-to-noise > 40 dB

µ

V for signal-to-noise > 50 dB

31 

µ

V for signal-to-noise > 60 dB

Connector

Standard type N, 50 

Shipping Weight

1 lb

Summary of Contents for FM250G

Page 1: ...FM250G Broadcast Transmitter User s Manual 2002 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: ...ted transcribed stored in a retrieval system or translated into any language in any form by any means without the written permission of Crown International Inc Printed in U S A Sony and RCA are tradem...

Page 3: ...2 3 1 Modulation Compensator 2 5 2 3 2 RF Tuning Adjustments 2 5 2 4 Receiver Frequency Selection 2 6 2 5 RF Connections 2 8 2 6 Audio Input Connections 2 9 2 7 SCA Input Connections 2 10 2 8 Composit...

Page 4: ...Pre Emphasis Selection 5 2 5 1 2 Pre Emphasis Fine Adjustment 5 2 5 2 Stereo Generator Adjustments 5 2 5 2 1 Separation 5 2 5 2 2 Composite Output 5 2 5 2 2 1 Using a Modulation Monitor 5 2 5 2 2 2 Us...

Page 5: ...ion 5 8 5 20 Additional Checks 5 8 Section 6 Reference Drawings 6 1 Views 6 2 6 2 Board Layouts and Schematics 6 4 Audio Processor 6 5 Stereo Generator 6 7 RF Exciter 6 9 Metering 6 11 Motherboard 6 1...

Page 6: ...Rev A FM250G User s Manual vi...

Page 7: ...TION Section 1 Getting Acquainted This section provides a general description of the FM250G transmitter and introduces you to safety conventions used within this document Review this material before i...

Page 8: ...procedure Simply select your operating frequency add an audio source attach an antenna and connect AC power and you re ready to broadcast Of course the FM series of transmitters also feature more soph...

Page 9: ...er which you can expect The number portion of each name represents the maximum RF output power The FM250G for example can generate up to 250 watts of RF output power Suffix letters describe the config...

Page 10: ...uration Crown transmitters have been used as booster transmitters Booster applications typically involve certain geographic factors which prevent your system from broadcasting to the full coverage are...

Page 11: ...ransmitters 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 retransmis...

Page 12: ...s the rest shifting the frequency in a manner that is unnoticeable to the listener 1 2 7 Nearcasting Some Crown units function as nearcast transmitters Their low power output is not designed for broad...

Page 13: ...0 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 Com...

Page 14: ...requency actual requirements for maximum voltage and current readings are 10 15 lower than stated Regulatory Meets CE and TUV requirements Dimensions 13 5 x 41 9 x 44 5 cm 5 25 x 16 5 x 17 5 inches We...

Page 15: ...DANGER 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 inju...

Page 16: ...Rev A FM250G User s Manual I 1 10...

Page 17: ...Installation 2 1 Section 2 Installation This section provides important guidelines for installing your transmitter Review this information carefully for proper installation fi...

Page 18: ...ke any changes To operate the FM250G at 120 volts make the following changes To change the voltage setting perform the following steps 1 Disconnect the power cord if it is attached 2 Open the cover of...

Page 19: ...nnect the AC power cord Illustration 2 1 Opening the Power Connector Cover Illustration 2 2 Removing the Voltage Selection red Assembly Input Power Fuze Size 120 VAC 10 ampere 240 VAC 4 ampere Table 2...

Page 20: ...ge the setting See Illustration 2 3 Top Cover Removed and Illustration 2 4 RF Exciter Board Frequency Selector Switches 3 Use small flat blade screwdriver or another suitable device to rotate the swit...

Page 21: ...nts All the RF stages are broadband to cover the 88 to 108 MHz broadcast band The RF amplifier stages require no tuning Note If you requested it the FSK chip on the RF Exciter Board has been pre progr...

Page 22: ...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 Boar...

Page 23: ...B 95 1 2 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...

Page 24: ...itor 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 conne...

Page 25: ...ly the one connecting to pin 3 should 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 balanc...

Page 26: ...generator To 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 Input section of the transmitter This will...

Page 27: ...tional information 2 11 Processor Bypass Option You may bypass the audio processor in order to feed the left and right pre emphasized audio directly to the stereo generator The Normal Bypass slide swi...

Page 28: ...4 Chassis Bottom View for board location 2 13 Remote I O Connector Remote control and remote metering of the transmitter is made possible through a 15 pin D sub connector on the rear panel No connecti...

Page 29: ...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 sy...

Page 30: ...Rev A FM250G User s Manual 2 14...

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