Nokia 6800 Series - Manual (Page 30)

6800/7000 Series - Distribution and Routing Products Installation and Operation Manual 3
Equalization Adjustment Chapter 1: AES-6880 AES/EBU Digital Audio Distribution Amplifier Module
Equalization Adjustment
The AES-6880 distribution amplifier provides two options for
equalization adjustment: Manual and Automatic. The mode is selected
using jumper J1 near the front edge of the DA card. See Figure 1-3 on
page 4 for jumper location.
Manual Equalization
In Manual adjust mode, a card-edge, multi-turn potentiometer (R19) is
used for adjusting equalization. The Confidence flag warning on the
card-edge LED is used to determine the amount of equalization required
without external test equipment. If the Confidence flag error LED is on,
then more equalization is needed.
To increase the amount of equalization, simply use a screwdriver to turn
the Manual equalization adjustment potentiometer (R19) clockwise until
the Confidence LED indicator turns off. See Figure 1-3 on page 4 for
potentiometer location.
Automatic Equalization
In Automatic adjust mode, the distribution amplifier automatically sets
the amount of cable equalization needed. This mode eliminates the need
to re-adjust equalization if another distribution amplifier is installed or
exchanged, or if the cable length changes.
The equalization is designed for using 2000 ft (600 m) of Belden 8281
cable or the equivalent. In practice, if the incoming signal is a standard
AES signal for coaxial cable systems, this DA can compensate up to 6000
ft (1800 m) of Belden 8281 cable or equivalent.
The factory default
configurations for J1 is in the
“Auto” position, and the
Manual
equalization
adjustment potentiometer
(R19) is set for zero
compensation.