Installation
SV-INTERCOM-2S Installation and User Guide - Revision A
2-7
Using Dim Input (Pin 5) Without SkyView Displays
Using Dim Input (Pin 5) Without SkyView
If you are using the SV-INTERCOM-2S without a SkyView system, and want to vary
the brightness of the SV-INTERCOM-2S’ backlighting, you must dim this using a
PWM dimmer that switches the ground side of the lighting circuit. A varying voltage
or resistance will not work.
Hook pin 5 to the negative terminal of your dimmer and the transmit/power LED
will dim with your dim control. This input may be connected in parallel with other
loads that are dimmed by the dimmer
Audio output from multiple SkyView displays must be connected together
The audio outputs from all SkyView displays must be connected together before
connection to their respective pins of the SV-INTERCOM-2S. More detail is available
in the SkyView System Installation Guide.
Allow sufficient room behind the SV-INTERCOM-2S for connector and cables
Audio wiring typically uses shielded cables, which can be stiffer, and larger, than DC
or data communications wiring typically used for avionics. It is recommended to
leave ample room beyond the connector for stiff, shielded wires to exit the
connector AND to form a large-enough “service loop” to allow the SV-INTERCOM-
2S to be removed from the panel with the connector for service and/or updates to
the audio wiring if needed.
Shielded audio cable is required
In an audio system such as the SV-INTERCOM-2S, it is required to use
separate
shielded cables for microphone and other input signals, and headphone and other
output signals. If separate shielded cables are not used, squealing, hum, and other
undesirable audio will likely be heard. To reduce electrical noise from being induced
into audio circuits, separate the audio wiring as much as possible from other
electrical wiring.
Audio cable shields must terminate at a common point
A ground loop is more than one electrical path to ground. Ground loops are a
common source of noise with audio systems. Because other electrical loads can
cause large current flows in a ground path, audio system grounds should be
isolated as much as possible from electrical ground. Except where specifically
directed in the diagrams above, the shields for all audio cables should terminate at
