Specifications

Table of Contents
2
DUC/RTAC or UDC Output Status Screen. . . . 3-84
Transmitter I/O Status screen . . . . . . . . . . . . . . 3-85
PFRU Status Screens. . . . . . . . . . . . . . . . . . . . . 3-87
Battery Backup Status Screen . . . . . . . . . . . . . . 3-90
Revisions Status Screens (1 & 2) . . . . . . . . . . . 3-91
Status Screens - ATSC Modulation . . . . . . . . . . 3-92
Status Screens - CTTB/CMMB Modulation . . . 3-97
Status Screens - ISDB-T Modulation . . . . . . . . 3-102
Status Screens - DVB-T Modulation . . . . . . . . 3-106
Status Screens - DVB-T2 Modulation . . . . . . . . 3-109
Status Screens - DAB Modulator. . . . . . . . . . . . 3-111
Section 4
Theory of Operation
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Active Logic Symbols . . . . . . . . . . . . . . . . . . . . . . 4-1
Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Modulator Overview . . . . . . . . . . . . . . . . . . . . . . . 4-4
Signal Processor Board Overview . . . . . . . . . . . 4-6
The Modulation Process . . . . . . . . . . . . . . . . . . . 4-7
RF Sample Processing. . . . . . . . . . . . . . . . . . . . . 4-7
Low Voltage Power Supply Board . . . . . . . . . . . 4-8
Battery Backup Option . . . . . . . . . . . . . . . . . . . . 4-9
ASI / SMPTE 310 Inputs / Output . . . . . . . . . . 4-11
PFRU (Precise Frequency Reference Unit) Board4-12
PFRU Board 1st LO PLL for the DAC Clock Circuit4-12
PFRU Board Local Oscillator-2 Circuit, For UDC 4-14
PFRU Board Reference Oscillator Circuit . . . . . . . 4-15
PFRU Board GPS Circuit . . . . . . . . . . . . . . . . . . . . 4-16
Up/Downconverter Board . . . . . . . . . . . . . . . . . 4-16
Upconverter Major Specifications . . . . . . . . . . . . . 4-16
Functional Description of Upconverter . . . . . . . . . 4-17
Downconverter Major Specifications . . . . . . . . . . . 4-18
Downconverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
LO Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
VAX-C Transmitter PAs . . . . . . . . . . . . . . . . . . . 4-21
Fault Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
RF Power Detection and Calibration . . . . . . . . . . . 4-21
+50 VDC Power Supply Interface . . . . . . . . . . . . . 4-22
Section 5
Maintenance and Alignments
Technical Assistance . . . . . . . . . . . . . . . . . . . . . . . 5-1
PA Module Removal and Replacement . . . . . . . . . 5-2
PA Module Removal . . . . . . . . . . . . . . . . . . . . . . 5-2
PA Module Installation . . . . . . . . . . . . . . . . . . . . 5-6
PS Module Removal/Replacement . . . . . . . . . . . . 5-8
Power Calibrations . . . . . . . . . . . . . . . . . . . . . . . 5-10
System Factory Fwd/Rfld Calibration . . . . . . . 5-12
Calibration Errors . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
Field Fwd/Rfld Calibration. . . . . . . . . . . . . . . . 5-14
Calibration Errors . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Pre-correction for Digital TV & DAB. . . . . . . . . 5-17
Precorrection Setup Procedure . . . . . . . . . . . . . 5-17
Troubleshooting Precorrection . . . . . . . . . . . . . . . . 5-18
Storing Precorrection . . . . . . . . . . . . . . . . . . . . 5-18
Changing Frequency . . . . . . . . . . . . . . . . . . . . . . 5-20
Fan Replacement . . . . . . . . . . . . . . . . . . . . . . . . 5-23
Air Filter Replacement . . . . . . . . . . . . . . . . . . . . 5-24
Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
Changing Date and Time Battery . . . . . . . . . . . . 5-26
Setting VAX-C Date and Time . . . . . . . . . . . . . 5-27
Battery Backup (UPS) Option . . . . . . . . . . . . . 5-27
Changing Feature Key. . . . . . . . . . . . . . . . . . . . . 5-29
Connecting To The VAX-C . . . . . . . . . . . . . . . . . 5-31
VAX-C Front and Rear RJ45 Connectors . . . . 5-31
Log- In Authorization Levels & Passwords . . . 5-32
Changing Passwords . . . . . . . . . . . . . . . . . . . . . 5-33
Connection Via Front Ethernet Connector . . . . 5-34
Assigning Computer IP Address in DHCP Client Mode5-35
Assigning Computer IP Address Without Rebooting5-35
Making the Connection to the VAX-C . . . . . . . . . . 5-36
Obtaining Rear Ethernet Connector Address . . . . . 5-36
Connecting Via VAX-C Rear Panel Ethernet Connector5-
37
Connecting To VAX-C Via Existing Ethernet Network5-37
Direct Connection, Computer To VAX-C Rear Ethernet Con-
nector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-38
Changing PC Operating Mode Static/DHCP . . 5-38
Verifying The Computer IP Address . . . . . . . . . . . 5-39
VAX-C Screen Captures . . . . . . . . . . . . . . . . . . . . . 5-40
Updating VAX-C Software . . . . . . . . . . . . . . . . . 5-41
Saving and Recalling Settings . . . . . . . . . . . . . 5-46
Web Browser Screen Captures . . . . . . . . . . . . . 5-47
Bootloader Recovery Procedure . . . . . . . . . . . . . 5-48
Connecting to the VAX via SNMP . . . . . . . . . . . 5-52
SNMP Configuration . . . . . . . . . . . . . . . . . . . . 5-52
Supported MIBs . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Harris Base MIB Description . . . . . . . . . . . . . . 5-53
Shortcuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Harris SMI (Structure of Managed Information)5-54
DAB Single Frequency Network (SFN) Setup . 5-56
Dynamic Delay . . . . . . . . . . . . . . . . . . . . . . . . . 5-56
Static Delay. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-56