Manual Gain Control; Transmitter Gain Control; Receiver Gain Control; Table 5 - Receiver Rf Signal Voltage - Foxcom Sat-light 7320 Installation And User Manual

7320 IFL Installation and User's Guide

5. Manual Gain Control

All internal adjustments have been set up at the factory; the only user adjustments are input
and output RF signal levels accessible from the front panel and described in the following
sections.

5.1 Transmitter Gain Control

Since MGC sets a constant input gain to the laser, an initial setup is required to ensure
the input signal level is not too high (over-driving the laser) or too low (noisy). These
variations can be caused by changes in dish pointing, rain fade or satellite channel
loading, or any other reason.
To prevent under-driving or over-driving the laser the signal level must be between 2 to
5VDC.
To set the Transmitter MGC:
1. Adjust the MGC potentiometer while monitoring the RF signal voltage. The 7320
IFL is designed to provide optimal output at 2.5V 0.5V. Therefore regardless of
the input the Manual Gain Control should be set to provide this output.
2. If there is input signal level variation expected, it is best to leave some
"headroom" should the signal level become too strong and result in distortion. It is
usually better to adjust the signal lower rather than higher.

5.2 Receiver Gain Control

Receiver Gain Control allows the user to set the output signal levels. The Gain
potentiometer is adjusted while monitoring the voltage of the Receiver "RF Sig."
Monitor (Pin #4 on the 6 Pin Connector). The chart below provides approximate
settings for desired output levels.

Table 5 - Receiver RF Signal Voltage

RF Output Level
-15 dBm
-20 dBm
-30 dBm
-35 dBm
Foxcom Proprietary Information
RF Signal Voltage Setting
9.0V 1
4.0V 0.5
0.75V 0.2
0.225V 0.02
Manual Gain Control
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