SkyTrac Systems Ltd.
Document Rev. 02.010
ISAT-100-OPD-SOI
Page 18 of 26
Restricted Proprietary and Confidential Information
4.7 Audio Installation:
4.7.1 Cautions:
Do not bundle ISAT audio wiring with 400 hz syncro wiring or AC power lines. Use
shielded cabling and apply ground exactly as indicated or significant audio interference can
result.
If connected directly to a headset, headset jacks should be isolated from airframe ground.
4.7.2 AUDIO LEVEL Adjustment
The Audio Output is short circuit protected.
When the ISAT-100 powers up, a tone will be played on the ISAT-100 Audio Output.
The AUDIO LEVEL can be adjusted via the AUDIO LEVEL potentiometer accessible via the
top of the ISAT.
To configure the AUDIO LEVEL, follow the below procedure:
1. Adjust ISAT-100 to minimum AUDIO LEVEL.
2. Establish a phone call.
3. Slowly increase the AUDIO LEVEL until desired volume is heard.
If audio signal quality begins to degrade while increasing AUDIO
LEVEL (power output limit reached), decrease level until signal quality
is good.
4.7.3 Audio Output Impedance Selection
The Audio Output impedance is selectable between 300 and 600 ohms via the selector
switch on the top of the ISAT.
4.7.4 MIC DC BIAS Selection
To provide a DC bias for microphone excitation place the MIC DC BIAS selector switch in
the ON position. To place a blocking capacitor in series, place the MIC DC BIAS selector
switch in the OFF position.
The MIC DC BIAS selector switch is accessible via the top of the ISAT.
The document reference is online, please check the correspondence between the online documentation and the printed version.
