Sigtronics SCI-S6 Installation Instructions - Manual (Page 6)

SCI-S4/SCI-S6 AUDIO PRIORITY TABLE
MODE ALL ISO CREW
AUDIO AUDIO IS MUTED BY:
PILOT MIC Co-pilot PTT* Never Muted Co-pilot PTT*
CO-PILOT MIC Pilot PTT* Co-pilot PTT Pilot PTT*
PASSENGER MICS
Pilot PTT or
Co-pilot PTT
Never Muted Never Muted
PILOT
ATC RADIO
Pilot PTT or
Co-pilot PTT
Never Muted
Pilot PTT or
Co-pilot PTT
CO-PILOT
ATC RADIO
Pilot PTT or
Co-pilot PTT
Always Muted
Pilot PTT or
Co-pilot PTT
PASSENGER
ATC RADIO
Pilot PTT or
Co-pilot PTT
Always Muted Always Muted
CREW MUSIC **
Pilot PTT, Co-pilot
PTT, ATC, Crew ICS,
or Pass ICS
Co-pilot PTT, Co-pilot
ICS, or Pass ICS
Pilot PTT, Co-pilot
PTT, ATC, or Crew ICS
PASS MUSIC **
Pilot PTT, Co-pilot
PTT, ATC, Crew ICS,
or Pass ICS
Co-pilot PTT, Co-pilot
ICS, or Pass ICS
Passenger ICS
NOTES:
ATC - Aircraft VHF Radio.
Crew - Pilot and Co-pilot.
ICS - Intercom Audio.
PTT - Push-To-Transmit Switch.
* Pilot Mic will always go out over the VHF radio when his PTT
is keyed. Co-pilot Mic will also go out when both PTT’s are
pressed, unless the “Pilot Transmit Priority” option is enabled.
** Music sources will partial mute on ICS, unless the “Full Music
Mute During ICS” option is enabled.
Stereo Music Systems
Most automotive stereo units operate from 12V-14V sources. If
you want to use these in a 28 volt aircraft do not connect them
directly to power. Regulators or converters are available to permit
operation from 24V-28V sources.
Some AM-FM music receivers are capable of causing interference
with aircraft COM and NAV receivers. The aircraft panel should be
placarded accordingly. Most player only units (cassette or CD) do
not cause interference with aircraft receivers.
Line level stereo music outputs can also be used into the SCI-S
system. Some line level outputs however, are a fixed level and are
not adjusted by the devices volume control. If this is the case you
will not be able to change the volume of the music you hear in the
headsets. Headphone level or Speaker level outputs would be bet-
ter in this case.
Stereo Headsets
The Sigtronics SCI-S systems are designed for use with general
aviation Stereo headsets with high impedance speakers (300 to
600 ohms). Headsets with low impedance (less than 100 ohms)
speakers should not be used with SCI-S systems without modi-
fication. Contact Sigtronics for details. In general, headsets with
speakers of high and low impedance and/or unmatched audio ef-
ficiencies should not be used together without modifications.
Sigtronics stereo headsets are specifically designed for the aircraft
high noise environment and give excellent noise attenuation. They
also provide full frequency response stereo for maximum enjoy-
ment. They are compatible with aircraft mic circuits and can be
used as general aviation headsets in aircraft that are not equipped
with stereo headphone jacks. This is because they include a switch
to change from “Stereo” to “Monaural”. No adapters required.
NOTE: General aviation headset (monaural) phone plugs should
not be plugged into SCI-S stereo phone jacks. A monaural plug
in a stereo jack shorts out one of the audio channels. This will not
damage the SCI-S system in any way but will cause reduced per-
formance. General aviation headsets may be used only if one of
the following three changes are made:
1. Monaural to stereo adapters are used on the headset head-
phone plugs. (Only monaural music will be heard.)
2. The general aviation headsets are re-wired for stereo reception.
3. Install the Sigtronics SCI-S system for monaural operation. See
note 6 on page 4 in the “WIRING INSTRUCTIONS” section.
See the separate SCI-S4/SCI-S6 OPERATING INSTRUCTIONS
sheet for complete operation information.
Sigtronics Corporation
178 East Arrow Highway
San Dimas, Ca 91773
(909) 305-9399
www.sigtronics.com
...when it counts!
SCI-S-INSL REV C 1-8-2007 P/N 700112
page 6