User's Manual

AT7120 Owner Manual Rev. 1.1 – March 2009 22/76
Section 3 – 8VSB Modulator and Master
Clock
Module 4549
Introduction
The Module 4549 is composed by an 8VSB MODULATOR including an IF pre-correction circuit board
(CIM3510) and the MASTER CLOCK UNIT, CIP8358.
Each one of these printed circuit boards are located below one of the two lateral covers of module 4549,
as it shows the drawing of external connections of this module.
(a)
(b)
Fig.3.1: Module 4549, (a) top view, (b) connectors, from rear panel
Internal 10MHz TCXO ref. input
10MHz OCXO ref. output to Up Converter
172MHz Master Clock
8VSB IF Modulated - 18.8339 MHz
IF (I) carrier
IF (Q) carrier
8VSB Modulator
Section
Master Clock
Section
Transport Stream Input
10MHz External Reference Input