background image

TX25/50 FM Broadcast Transmitter

No part of this manual may be re-produced in any form without prior written permission from BW Broadcast. 

The information and specifications contained in this document is subject to change at any time without notice.

Copyright 2009 BW Broadcast

www.bwbroadcast.com

Technical manual

Содержание TX25

Страница 1: ...may be re produced in any form without prior written permission from BW Broadcast The information and specifications contained in this document is subject to change at any time without notice Copyrigh...

Страница 2: ...1 MPX loop through is set to ON If you intend to connect a MPX signal to the MPX input BNC connector you will need to move J1 MPX loop through to the OFF position Examples of configurations requiring...

Страница 3: ...ex Broadband Input 2 53 Stereo With Limiters 2 54 Stereo With Limiters Disabled 2 55 Mono From Two Channels 2 56 Mono From One Channel 2 6 Other Setup Considerations 3 Technical data 3 1 Specification...

Страница 4: ...y normally only found on expensive test equipment Local and remote personal computer control and metering are achievable via RS232 interface and there s an alarm I O as well The FM modulator section e...

Страница 5: ...evice complies with the requirements of the 1995 5 EC Radio and Telecommuni cations Terminal Equipment R TTE The equipment will meet or exceed the following standards EN 60215 1996 Safety Requirements...

Страница 6: ...he left and right program audio signals to the XLR input connectors on the back of the transmit ter Plug in the power cord to the transmitter Once the transmitter is operating set the correct carrier...

Страница 7: ...e RDS encoder Connect the MPX output of the RDS encoder to the MPX input on the back of the transmitter Plug in the power cord to the transmitter Once the transmitter is operating set the correct carr...

Страница 8: ...rrier frequency from the front panel this can also be locked and set internally Adjust the desired power output level using front panel Check reflect ed power is OK Check the modulation level if the m...

Страница 9: ...itter Once the transmitter is operating set the correct carrier frequency from the front panel this can also be locked and set internally Adjust the desired power output level using front panel Check...

Страница 10: ...Plug in the power cord to the transmitter Once the transmitter is operating set the correct carrier frequency from the front panel this can also be locked and set internally Adjust the desired power o...

Страница 11: ...t Pin 1 MOD failure alarm TTL Pin 2 PLL failure alarm TTL Pin 3 RF failure alarm TTL Pin 4 RF Mute Pin 5 18V DC 200mA Pin 6 MOD failure alarm OC Pin 7 PLL failure alarm OC Pin 8 RF failure alarm OC Pi...

Страница 12: ...z frequency steps from 87 5 to 108Mhz if the internal switches are set to 4440 If the frequency is set internally with the rotary switches then the up down buttons will give a not allowed message Peak...

Страница 13: ...8 represents 100 kHz on the 12 5 kHz switch 8 x 0 125MHz 0 1MHz 100kHz The LCD display on the front panel will display the frequency that you have set on the internal switches If you try to adjust th...

Страница 14: ...een to provide adjustment of the R F power down from that maximum power set point This can be desir able in transmitter hire situations where you wish to govern the maximum output to a fixed level but...

Страница 15: ...he fault condition exists for sixty seconds or more You will need to reset the trans mitter to clear the alarm s or you can do it via RS232 connection MODULATION FAILURE The Modulation failure alarm w...

Страница 16: ...our com puter that is running the application Connect a serial cable between the RS232 connector on the rear of the transmitter and one of your computers COM ports If you are using a codec or other ST...

Страница 17: ...response to your function For example If you pressed o for R F Mute you would not see the effect of the R F power change until you refreshed the screen again because the terminal win dow would still b...

Страница 18: ...2 5 MODES OF OPERATION The transmitter is fully configurable and can be set up to support various modes of operation The mode of opera tion is set by the configuration of the internal jumpers This cha...

Страница 19: ...e are two different standards in use worldwide In Europe and Africa the standard is normally 50 s This represents a lift of about 3dB at 3 kHz and 10dB at 10 kHz In the Americas and in Japan more boos...

Страница 20: ...be disabled by putting Jumper 8 in the OFF position This one jumper controls both channels because the gain reduction control voltage which this jumper disables is common to left and right Even with...

Страница 21: ...ation The multiplex signal is then fed through to the exciter module and to the back panel multiplex output BNC socket See loopthrough mode below JUMPERS J1 ON J2 3 50 or 75 J4 5 LOUD or CLARITY J6 7...

Страница 22: ...connect the signal from the internal limiter and stereo encoder to an external piece of equipment before being reinjected back into the transmitter via the multiplex input socket The most common appli...

Страница 23: ...he input drive to the limiter module and can be set so that limiting occurs for a given input level Factory setting is at maximum to enable maximum compression limiting so that a loud commercial sound...

Страница 24: ...vel All that is left to do is to set the input gain controls to your desired settings For most applications where you require a compressed loud competi tive sound we recommend setting the gain control...

Страница 25: ...distortion to a minimum Connect a multimeter set to millivolts to testpoint TP1 which is located next to the right clipper jumper You will also need an earth point for the meter The bolt on REG2 is a...

Страница 26: ...urn the power off to the transmitter connect your external antenna reconnect the power and your on the air 14 Monitor your total peak deviation with your real world audio material and check with the d...

Страница 27: ...bu The limiters inputs will need at least a 0dbu input to achieve limiting even with the rear panel gain controls set at maximum Read the pre emphasis note at the end of the sec tion for more info on...

Страница 28: ...troducing distortion To ensure you can reduce your input level or reduce the rear panel gain controls 15 kHz FILTER CLIPPERS PLEASE NOTE In some situations clipping after 15 kHz filters can cause degr...

Страница 29: ...adjustment of the VCO frequency when locked This will have been adjusted at factory to the correct setting and the transmit ter should remain within 1kHz of the channel required If however the frequen...

Страница 30: ...0W TX50 N type 50 Ohm better than 88 dBc 90 dBc 87 5 108 MHz 100 kHz from LCD or 12 5 kHz from internal switches Internal switches or LCD system Dual speed phase locked loop 500 Hz fine adjustment ava...

Страница 31: ...gnals are applied to balanced input XLR sockets on the back panel The balanced audio signals are fed to IC1 IC4 which are configured as differential amplifiers to convert the balanced inputs to unbal...

Страница 32: ...er is buffered by output op amp IC15 which also provides a fixed output level of 6dBu which is fed to the multiplex output BNC socket on the back panel as well as to one side of the loopthrough jumper...

Страница 33: ...crocontroller has several ports that have various functions and connect to external com ponents PORTA 6 bits is primarily used for the analogue voltage inputs Bit 0 is the limiter gain reduction Bit 1...

Страница 34: ...ng input of side B of the op amp LED3 only allows DC through above a certain level Any DC above this level will increase the output voltage from the op amp and the RF power level will decrease This fo...

Страница 35: ...ferrite ring RFT1 This ring also has 14 turns of wire as a secondary winding IC2 and associated resistors R24 R47 buffer the sensors outputs and provide a level suitable for the control LCD boards mic...

Страница 36: ...BW Broadcast technical manual Page 36 Technical data 3 3 BLOCK DIAGRAM...

Страница 37: ...blue 24 0 2 W brown 24 0 2 W4 red 24 0 2 tri rated W5 yellow 24 0 2 W6 black 24 0 2 tri rated W7 black 24 0 2 W8 red 24 0 2 W6 W4 W1 W6 W4 W5 W7 W8 W1 W3 W2 W4 W5 W8 W6 W7 RF MOD MON BNC s 16 WY RIBBO...

Страница 38: ...7 VR1 VR LEFT IN HOT COLD GND CON4 R44 R50 C46 C45 R45 3 2 1 8 4 IC2 A C 8 R46 R51 5 6 7 IC2 B R5 C42 R52 R6 2 3 4 1 6 5 12 IC5 A C55 C54 R59 R58 R60 3 2 1 8 4 IC7 1 D5 D7 5 6 7 IC7 B D12 C56 5 6 7 IC...

Страница 39: ...3 9 RB4 11 RB5 10 RB7 13 MCLR 4 OSC1 16 RB6 12 GND 5 VCC 14 OSC2 15 IC13 R90 R98 R91 R92 R93 VR6 R102 R101 3 2 6 IC14 R103 C75 R104 R105 C79 C78 C80 C81 82 C83 L1 L2 C84 3 2 6 1 8 IC15 R107 C86 R106 R...

Страница 40: ...4 C16 5V RF OUTPUT 15 VDC 5V R1 R29 D2 15 VDC R 1 X 1 Y 2 C 1 IC19 A R9 10V 10 VDC 5V C12 C6 C9 C8 C17 C18 C1 0 9 8 4 1 2 5 6 7 SW1 0 9 8 4 1 2 5 6 7 SW2 0 9 8 4 1 2 5 6 7 SW C7 RFT1 R12 LED5 VOLT REG...

Страница 41: ...BW Broadcast technical manual Page 41 Technical data 3 52 LCD CONTROL BOARD...

Страница 42: ...1 REG1 C9 C8 18V REG R8 1 2 VR1 CON5 8 CON5 9 C5 C18 C21 C20 C19 L5 C2 C24 L6 C22 C25 C26 C27 C 0 R16 C 2 CON 1 R14 R1 C 4 V V 2 ADJ 1 TS1 C16 R15 C 1 4 2 CON5 1 4 2 CON4 R11 C6 R10 C14 R21 C 1 1 2 4...

Страница 43: ...Series 8 C4 C38 C39 C42 C43 C50 C52 C56 47pF General Purpose Ceramic Disc 2 5mm pitch 2 C73 C94 33pF General Purpose Ceramic Disc 2 5mm pitch 2 C34 C20 47pF Ceramic Plate 2 5mm pitch 680 Series 2 C46...

Страница 44: ...01 xx 12 J1 12 3 pin 3 Pin Jumper Header 2 54mm 3 Way Row 12 J1 12 LINKS n a Jumper Link 2 54mm Protech Easy Pull Style 1 RFT1 1 Turn 1 Complete Turn Ferrite Core 4 SW1 4 Dec Rota Decimal Rotary PCB S...

Страница 45: ...e Tolerance 1 1 R95 4K3 1 4 Watt Metal Oxide Tolerance 1 1 R128 51R 1 4 Watt Metal Oxide Tolerance 1 2 R129 R130 4k7 1 4 Watt Metal Oxide Tolerance 1 3 R133 R134 470R 0 6 Watt Metal Oxide Tolerance 1...

Страница 46: ...Metal Film 1 CR12 6 R3 R7 R8 R9 R10 R11 820R 1 8 W Metal Film 1 CR12 2 R4 R5 390R 1 8 W Metal Film 1 CR12 1 R6 10k 1 8 W Metal Film 1 CR12 1 R21 4k7 1 8 W Metal Film 1 CR12 1 R23 R24 4R7 1 8 W Metal F...

Страница 47: ...stor 1 VR2 10k 63M series Variable Resistor 1 VR3 1k 63M series Variable Resistor 1 VR4 100k 4mm SMT Pot Trimmer 1 D3 n a Green LED 1 J1 2n2 5mm Pitch Ceramic Disc 1 C1 n a Wire Link Resistor leg 1 C2...

Страница 48: ...AIR 0 9mm Silvered wire coil 5 86mm 3 5T 2turn spacing hole through legs 2 L8 L9 High Freq Version 1 L10 IND AIR High Freq Version 2 D1 D2 BAT42 30V SILICON SCHOTTKY DIODE 1 T1 MRF173 RF Transistor 1...

Страница 49: ...www bwbroadcast com...

Отзывы: