Related Manuals for Cable AML ITX21-100
Summary of Contents for Cable AML ITX21-100
- Page 1 Cable AML Installation Maintenance Manual Indoor Broadband Transmitter Model: ITX21-100...
- Page 2 INSTALLATION AND MAINTENANCE MANUAL Indoor Broadband Transmitter Model: ITX21-100 Cable AML, Inc. 3427 W. Lomita Boulevard Torrance, California 90505 USA TEL 310 517-8888 or 702 363-5660 FAX 310 517-8555 or 702 363-2960 Copyright ©2004 Cable AML, Inc. IM4030013-1 Rev – 20040713...
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Page 3: Table Of Contents
Indoor Broadband Transmitter – ITX21-100 TABLE OF CONTENTS Section Page 1.0 INTRODUCTION ...................... 1 2.0 CIRCUIT DESCRIPTION..................7 2.1 Upconverter Section....................... 7 2.2 Power Amplifier Chains ....................7 2.3 Power Supply Assembly....................8 2.4 Diagnostic Circuits ......................8 2.5 On-Delay Timer Assembly ..................... 8 3.0 INSTALLATION ....................... - Page 4 ITX21-100 Block Diagram................5 DC Diagnostics Switch Positions..............8 Front Panel Connection Points..............10 Rear Panel Connection Points..............11 Output Level Adjustment................13 LIST OF TABLES Table Page Typical Channel Loading for ITX21-100 Input/Output Levels ......10 IM4030013-1 Rev –...
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Page 5: Introduction
Indoor Broadband Transmitter – ITX21-100 1.0 INTRODUCTION The ITX21-100 shown in Figure 1 is a solid-state broadband transmitter that converts a VHF input signal of 119 MHz to a microwave signal of 2.159 GHz. The ITX21-100transmitter consists of the following assemblies (refer to Figure 2). -
Page 6: Itx21-100 Broadband Transmitter
Indoor Broadband Transmitter – ITX21-100 Figure 1. ITX21-100 Broadband Transmitter. IM4030013-1 Rev –... -
Page 7: Itx21-100 Component Layout
Indoor Broadband Transmitter – ITX21-100 Local Oscillator Local Filter Oscillator Meter On- Delay Timer Circuit VHF Processor +12 VDC Fan Upconverter (Power Amp Test-Point Underneath) +12 VDC Power Supply +24 VDC Power Supply Output Circulator Figure 2. ITX21-100 Component Layout. - Page 8 Indoor Broadband Transmitter – ITX21-100 This Page Intentionally Left Blank.) IM4030013-1 Rev –...
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Page 9: Itx21-100 Block Diagram
Indoor Broadband Transmitter – ITX21-100 87194-000 G=12 dB VHF PROCESSOR FILTER NOTCH DIR COUPLER MIXER ISOLATOR FILTER BPF COAX F 42106-001 87103-221 87112-013 87102-210 87202-019 87110-005 G= -8 dB VHF INPUT 116-128 MHz 25 dBmV/Ch 2 Channels ISOL DIR COUPLER... - Page 10 Indoor Broadband Transmitter – ITX21-100 (This Page Intentionally Left Blank) IM4030013-1 Rev ––...
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Page 11: Circuit Description
Indoor Broadband Transmitter – ITX21-100 2.0 CIRCUIT DESCRIPTION The ITX21-100Transmitter consists of the following circuits or modules: Upconverter Section Power Amplifier Power Supply System Monitoring and Diagnostic Circuits - connectors and switches. On-Delay Timer Assembly. In addition, microwave isolators and filters are used as necessary to ensure the stability and purity of transmitted signals. -
Page 12: Power Supply Assembly
Indoor Broadband Transmitter – ITX21-100 2.3 Power Supply Assembly Two +12 VDC and one +24 VDC power supplies are used to provide the DC voltage. A +12 VDC linear power supply is used to provide power to the internal downconverter and Local Oscillator. -
Page 13: Installation
It should be placed near the rear of the transmitter. 3.3 Input Voltage Requirements Cable AML transmitters can be equipped to operate on either 120 or 240 VAC at either 50 or 60 Hz. This option is specified by customer request, and each unit is shipped according to this specification. -
Page 14: Front Panel Connection Points
Indoor Broadband Transmitter – ITX21-100 Table 1. Typical Channel Loading for ITX21-100 Input/Output Levels Number Of Output Level From Input Level To Transmitter Channels Transmitter 31.5 dBmV/Channel 27.5 dBm/Channel 30.0 dBmV/Channel 26.0 dBm/Channel 28.0 dBmV/Channel 24.0 dBm/Channel 26.0 dBmV/Channel 22.0 dBm/Channel 25.0 dBmV/Channel... -
Page 15: Rear Panel Connection Points
Indoor Broadband Transmitter – ITX21-100 Figure 6. Rear Panel Connection Points. IM4030013-1 Rev –... - Page 16 Indoor Broadband Transmitter – ITX21-100 (This Page Intentionally Left Black.) IM4030013-1 Rev –...
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Page 17: Operation
4.1 Output Level Setting The output power for each ITX21-100 Transmitter Unit depends entirely on the input level. If the input level at VHF is higher than the recommended value, both the output power and the CTB (Composite Triple Beat) distortion will increase. -
Page 18: Ambient Conditions
Indoor Broadband Transmitter – ITX21-100 4.2 Ambient Conditions The ITX21-100 transmitter is designed to operate with no external cooling devices. Internal cooling fans maintain component temperatures at desirable levels when ambient conditions are in the range specified in Section 6.0 - Specifications. -
Page 19: Maintenance And Troubleshooting
Indoor Broadband Transmitter – ITX21-100 5.0 MAINTENANCE AND TROUBLESHOOTING 5.1 Maintenance Maintenance is not normally required for the ITX21-100 after initial installation. However input and output power levels should be measured periodically and adjustments made if necessary. The output power level should be measured and adjusted as described in Section 4.0 of this manual. -
Page 20: Internal Troubleshooting
Indoor Broadband Transmitter – ITX21-100 5.3 Internal Troubleshooting Remove the cover of the transmitter. WARNING Internal troubleshooting requires that: Power remains on. Transmitter cover is removed. CONTACT WITH LINE VOLTAGE CAN BE FATAL! It is recommended that internal troubleshooting be limited to personnel skilled in maintenance of microwave transmitters or receivers. - Page 21 Indoor Broadband Transmitter – ITX21-100 Power Amplifiers not Warm If the amplifier fins are cool, then check for AC at the input to the amplifier power supply. If AC is present at the input to the power supply and the amplifier is cool then replace the amplifier.
- Page 22 Indoor Broadband Transmitter – ITX21-100 This Page Intentionally Left Blank.) IM4030013-1 Rev –...
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Page 23: Specifications
Indoor Broadband Transmitter – ITX21-100 6.0 SPECIFICATIONS ITX21-100 Transmitter Input Frequency 119 MHz Nominal Input Level for 1 TV: +40 dBmV Output Frequency 2.159 GHz Average Power Peak Power Channels C/N (dB) dBm/Channel dBm/Channel Output Level for 50 dB C/IM: 37.5...