Cisco Cisco 1 GHz GainMaker Amplifier Guía De Instalación
2
4015992 Rev D
Overview
System Requirements
As its name implies, the QAM AGC is intended to operate with a QAM carrier
serving as the pilot carrier. While the QAM AGC operates similarly to the
standard single pilot AGCs (which required either a CW or NTSC modulated
carrier as the pilot), optimum system performance is achieved when the following
guidelines are followed:
The pilot carrier must be a QAM carrier. (Typically 64QAM or 256QAM -
with approximately 6 MHz occupied bandwidth.)
The QAM pilot carrier's RF level must be set properly at the headend or hub
site.
The QAM pilot carrier should always be modulated. (If changed to CW mode,
the AGC may detect a slight power change and alter RF levels.)
Channels adjacent to the pilot should also be present. (If they are empty
channel slots that are filled later, the AGC may detect a slight power change
and alter RF levels.)