SCI-S4_SCI-S6 Installation Ins
Sigtronics SCI-S4 / SCI-S6 Installation Instructions
INTRODUCTION
ATTENTION INSTALLER: To assure a trouble free installation, please read the entire instructions through once
before beginning.
SCI-S4/SCI-S6 SYSTEM SPECIFICATIONS
CONFIGURATION - The Sigtronics SCI-S Intercom systems are
specifically designed for permanent, panel mounted installation
in aircraft. Up to four-position intercom is provided with the model
SCI-S4. Model SCI-S6 handles up to six positions. “H” Model
units for use in high noise aircraft.
UPGRADE - An SCI-S4 or SCI-S6 can replace an existing SPA400, SPA-600, ST-400, or ST-600 installation. This requires minor
mounting hole changes and minimal re-wiring.
DUAL STEREO MUSIC INPUTS - Both Crew and Passengers
music inputs accept standard headphone (Walkman) or line level
inputs. Automobile Speaker level outputs can be adapted for use
with the SCI-S systems.
COMPATIBILITY - Sigtronics SCI-S intercoms have been designed to operate with all standard general aviation aircraft radios
and headsets.
SIZE: Panel 1” x 2.5”. Chassis - 1” high x 2.5” wide x 6” deep. Can
be mounted either horizontally or vertically in the aircraft panel.
WEIGHT: 7.3 ounces (SCI-S4 intercom unit with panel and knobs).
Jacks and wiring harness weigh 8.9 ounces. 7.5 ounces (SCI-S6
intercom unit with panel and knobs). Jacks and wiring harness
weigh 10.9 ounces.
INPUT POWER: 11VDC through 32VDC. Maximum current drain
0.2 Amp (SCI-S6)
DISTORTION: Less than 1% total harmonic distortion.
WARRANTY: The SCI-S units are constructed of high quality components and carry a five year parts and labor warranty.
FAA TSO: C-50c
ENVIRONMENTAL: DO-160D
Environmental Catagory:
A1D1XCAAS2MXXXXXXZBBBBXXXXXXXXXXX
MADE IN THE USA
SCI-S4
SCI-S6
Headphone Output Jacks - Accept standard
0.250” aircraft stereo headphone plugs
4
6
Microphone Input Jacks - Accept standard
0.206” aircraft microphone plugs. (U93 plug
compatible jacks can be used in place of the
jacks provided - mono installations only)
4
6
Mic Jack Insulating Washers, Flat
4
6
Mic Jack Insulating Washers, Shoulder
4
6
Intercom Panel - lettered on both sides.
1
1
Intercom Control Knobs
4
4
Mounting Screws 4-40 x 1/2
2
2
Drill Template - Adhesive backed hole size
pattern for drilling aircraft panel
1
1
Intercom/Aircraft Interface Cable (4 feet
long)
1
1
Headphone/Music Interface Cable (4 feet
long)
1
1
Stereo music input jacks 3.5mm
2
2
INTERCOM OPTIONS
The SCI-S intercoms have two options that can be enabled if desired. Installing small jumper wires on the solder side of the circuit
board enables these options. As such they have to be installed
before the unit is installed into the aircraft.
HARDWARE SUPPLIED
Besides the intercom unit and instructions, each SCI-S system
comes with the following hardware:
Specialists in “SOUND” Management
178 East Arrow Highway, San Dimas, CA 91773 ( 909 ) 305-9399
OPTION “A” - FULL MUSIC MUTE DURING ICS - When listening
to music and someone speaks on the intercom the default factory operation is to partially mute the music so you can hear the
conversation. If you prefer however, the music can be completely
muted during intercom if you enable this option. Note - during radio
transmission and reception, the music will always be fully muted
regardless if this option is selected or not. This is for communication safety reasons.
OPTION “B” - PILOT TRANSMIT PRIORITY - If the pilot and the
copilot key at the same time (not a common occurrence) the default
operation is that both microphones will go out the aircraft radio to
the tower. If you prefer only the pilot’s microphone active when both
press their PTT’s simultaneously then enable this option. Note - if
only one of the pilots
presses his PTT only
his mic will go out over
the radio regardless if
this option is selected
or not.
To enable either or
both of these options,
remove the four screws
on the bottom of the
SCI-S unit and remove
the cover. Refer to
Figure 1. To enable option A (full music mute
during ICS), solder a
small jumper from the
pad labeled “A” to the
pad labeled “G”. To enable option B (pilot transmit priority) solder
a small jumper between pad “B” and pad “G”. Replace the cover
and the four screws and tighten. Removing these jumpers will deactivate the options.
CHASSIS INSTALLATION
4. Enlarge two holes to 9/16”, one hole to 7/16”, and two holes to
3/16” per the template.
MOUNTING CHASSIS (See Figure 2)
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1. Remove the knobs from the Volume and Squelch controls using
a 0.050” Allen wrench. NOTE: DO NOT REMOVE the nuts from
the Volume/Squelch, or ALL/ISO/CREW controls.
2. Insert the SCI-S unit from the rear of the aircraft panel with the
appropriate arrow on the unit chassis pointing upwards. Make
sure the squelch indicator lights have unrestricted movement
through aircraft panel.
3. Install the printed SCI-S panel and lightly thread the two 4-40
screws through the holes in intercom panel. The nuts on the
Volume/Squelch and ALL/ISO/CREW controls will fit inside the
9/16” and 7/16” diameter holes.
4. Tighten the two screws.
5. Install the knobs on the Volume (VOL) and Squelch (SQ) control
shafts and tighten the Allen screws.
To upgrade an existing SPA-400 installation to an SCI-S4 or a SPA600 to an SCI-S6 skip to the “UPGRADING A SPA INSTALLATION
TO A SCI-S” section on page 4. For a completely new intercom
installation, continue below.
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UNIT PLACEMENT
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The SCI-S unit has been designed to mount either horizontally or
vertically in your aircraft panel. The location selected for the SCIS unit requires a minimum front panel area of 2 1/2” by 1”. Depth
required behind panel is 6” plus cable access.
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Microphone Jack
CAUTION: Move the aircraft flight controls through the limits of
travel while observing the selected area and making sure that the
rear of the intercom and cable will not interfere with any aircraft
control components.
PANEL PREPARATION:
1. Position the adhesive drill template on the aircraft panel in the
selected area.
2. Center punch each hole at the cross lines. (Five holes are in
a straight line and equally spaced 0.4” apart. The two Squelch
Indicator Light holes are 0.8” apart).
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Figure 3
MOUNTING HEADPHONE AND MICROPHONE JACKS (See
Figure 3)
1. Locate the mounting areas. (One mic and one headphone jack
required for each headset). Again, make sure that the jacks will
not interfere with any aircraft control components. (Note that the
jack contacts will expand when a plug is inserted into the jack.)
2. Drill 3/8” diameter holes for headphone jacks and install.
3. Drill 1/2” diameter holes for the mic jacks and install with the
insulating washers supplied. (See Figure 3)
3. Drill 1/8” pilot holes in all seven places.
page 2
Note: If the aircraft already has pilot headset jacks, the location
can be used for intercom with the following changes. The mic
jack must be re-wired as follows:
TABLE 1 - P1/J1 - See Wiring Instructions
PIN
1. Remove any existing wires from the tip, ring, and barrel connections.
WIRE COLOR
FUNCTION
CONNECT TO
1
White/Black
Pilot Mic Input
Ring Terminal of Pilot Mic Jack
2
White/Red
Pilot Transmit Switch
Input
Pilot Transmit Switch (PTT) (Switch to
Ground to Transmit)
3
Blue
*1
Radio Headphone Input
Radio Headphone Output
*2
Intercom Central
Grounding Point “A”
Aircraft Chassis Ground
2. Connect the intercom white/black wire to the ring terminal.
4
Black
3. Connect one end of a wire to the barrel terminal of the mic jack
and connect the other end to Point “A”.
5
White
Radio Transmit Key
Output
Tip Terminal of Aircraft Hand Mic Jack,
or Key Input of Aircraft Radio or Audio
Panel
6
Brown
Transmit Mic Audio
Output
Ring Terminal of Aircraft Hand Mic
Jack or Mic Input of Aircraft Radio or
Audio Panel
7
Red
*3
12 through 28 VDC
Power Input
Intercom Circuit Breaker
8
Tan
*4
Passenger #1 Mic Input
Ring Terminal of Passenger #1
Intercom Mic Jack
9
Tan
*4
Passenger #2 Mic Input
Ring Terminal of Passenger #2
Intercom Mic Jack
10
White/Blue
Co-Pilot Transmit Switch
Input
Co-Pilot Transmit Switch (PTT) (Switch
to Ground to Transmit)
4. Install insulating washers as necessary if the barrel of the mic
jack is mounted in metal.
For the headphone jack, replace the mono headphone jack with
the stereo headphone jack. Connect the green wire (P2 pin 1) to
the tip connection. Connect the white/green wire (P2 pin 7) to the
ring connection.
WIRING INSTRUCTIONS
Connections should be made as shown in Figure 4 and indicated
in Tables 1 and 2. If longer wire lengths are required, use a good
quality hook-up wire - 22 gauge or larger. Although not necessary,
shielded audio wire can be used if desired. This can simplify the
wiring process.
11
White/Orange
Co-Pilot Mic Input
Ring Terminal of Co-Pilot Mic Jack
12
N/C
None
No Connection
13
Tan
*5
Passenger #3 Mic Input
Ring Terminal of Passenger #3
Intercom Mic Jack
14
Tan
*5
Passenger #4 Mic Input
Ring Terminal of Passenger #4
Intercom Mic Jack
15
N/C
None
No Connection
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page 3
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as shown in Figure 4. Identify the jack terminals using Figure 5.
Connect the White/Brown, White/Violet, and Black wires to the
second jack. Drill a 1/4-inch hole for each jack and mount on the
aircraft panel. To use, connect an adapter cable between the
music input jack and the output of the portable stereo. Suitable
cables are available at your local Stereo or electronics store as
well as from Sigtronics.
TABLE 2 - J2/P2 - See Wiring Instructions
PIN
WIRE COLOR
FUNCTION
CONNECT TO
1
Green
*7
Pilot Intercom Right
Headphone Output
2
Grey
*7
Co-Pilot Intercom Right
Headphone Output
Tip Terminal of Co-Pilot Headphone
Jack
3
Yellow
*7
Passenger Intercom
Right Headphone
Output
Tip Terminal of Passenger
Headphone Jacks
Left Crew Music Source
Hdph/Line Output
Tip Terminal of Pilot Headphone Jack
4
Orange
*6
Crew Music Input
Left Channel
5
Black
*6
Crew Music Input
Common
Crew Music Source
Common Hdph/Line Output
6
Violet
*6
Crew Music Input
Right Channel
Right Crew Music Source Hdph/Line
output
7
White/Green *7
Pilot Intercom Left
Headphone Output
Ring Terminal of Pilot Headphone
Jack
8
White/Grey
Co-Pilot Intercom Left
Headphone Output
Ring Terminal of Co-Pilot Headphone
Jack
9
White/Yellow *7
Passenger Intercom
Left Headphone Output
Ring Terminal of Passenger
Headphone Jacks
10
White/Brown *6
Passenger Music Input
Left Channel
Left Passenger Music Source Hdph/
Line output
11
Black
*6
Passenger Music Input
Common
Passenger Music Source Hdph/Line
Common Output
12
White/Violet *6
Passenger Music Input
Right Channel
Right Passenger Music Source
Hdph/Line Output
*7
If only a single portable music source is to be used there are
two different methods this can be done. The first way and most
flexible is to wire just like the wiring drawing and use a mini-jack
“Y” or splitter (also available at your local Stereo or electronics
store) and dual cables to go from one stereo into both crew and
passenger input jacks. The second way is to use just one of the
supplied music input jacks and connect both inputs to it. Do this
by connecting both the Orange and the White/Brown wire to the
TIP terminal, the Violet and White/Violet to the RING, and both
Blacks to the BARREL.
Speaker level output car stereo music sources can also be used
with the SCI-S system. A Floating Ground Adapter or a four wire
to three wire converter will have to be used between the Stereo
and the SCI-S music inputs. Figure 6 shows such an adapter
and how it is wired into the SCI-S.
1. The blue wire from Pin 3 must be connected to the aircraft radio
headphone output - NOT the speaker output.
2. Connect all intercom mic jack grounds to a single aircraft chassis ground point - Point “A” - as shown in Figure 4. (Use the
black washers supplied to insulate the intercom mic jacks from
aircraft chassis ground). Note this intercom central grounding
point is used to eliminate any unwanted electrical noises, such
as alternator whine or strobe noise, from being induced into the
intercom system through the grounds. All intercom mic jack barrels must be insulated from ground where they are mounted and
connected back to Point “A” on their own individual ground wire.
Similarly, both intercom ground wires (J1 pin 4) and the push-totransmit switch grounds must also be connected back to Point
“A”. It is not necessary, however, to connect the headphone jack
barrels to Point “A”. They can either be grounded where they are
mounted or some place nearby.
7. The Sigtronics SCI-S system can be installed as shown for use
with Stereo headsets. Alternatively, monaural general aviation
type headsets can be used. To use monaural headsets follow
the installation instructions as normal except for the wiring of
the stereo headphone jacks. Use the stereo headphone jacks
supplied with the Sigtronics SCI-S but leave the “RING” connections open. Instead connect both headphone wires to the
“TIP” of the respective jacks. Connect both the WHITE/GREEN
and GREEN on to the TIP of the pilot jack, WHITE/GREY and
GREY on the copilot’s and WHITE/YELLOW and YELLOW on
the passengers.
3. The red wire may be connected to either 12V (14V) or 24V (28V)
power source. No switching or adjustments are required to operate from either source.
5. Tan wires pins 13 and 14 are provided on SCI-S6 units only.
6. The SCI-S system provides two separate music inputs - one
for the crew and the other for the passengers. These music
inputs accept Headphone
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(Walkman) or Line level
music sources. The wiring diagram shows how
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to wire the SCI-S for dual
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music inputs for use with
portable stereo music
sources. Two small stereo ����
input jacks are supplied ������
for this purpose. Connect
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the Orange, Violet, and
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Black wires to one jack
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4. Tan wires (J1 pins 8, 9, 13, 14) are only used on installations that
require extra intercom positions.
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8. Make sure any unused wires are properly insulated and kept
from shorting to any other wires or aircraft ground. Skip down to
the “INSTALLATION CHECK OUT AND ADJUSTMENT” section
on page 5.
UPGRADING A SPA INSTALLATION TO A SCI-S
Chassis Mounting
The SCI-S4 is specifically designed to easily replace a SPA-400.
Similarly, the SCI-S6 can replace a SPA-600. The panels are exactly the same dimensions (1” x 2.5”), however the SCI-S units are
1 3/4” longer than the SPA units. You will have to make sure that
you have the extra depth required behind your panel. Five mounting holes are exactly in the same positions. The center hole will
have to be enlarged from 1/4” to 7/16”, the two outer holes will have
to be enlarged to 9/16”, and two additional holes drilled to 3/16” (As
per template).
page 4
To upgrade, first remove the SPA unit from the aircraft panel. This
is done by unscrewing the two Phillips head screws and the nut on
the ON/OFF switch. Remove the printed SPA panel. Pull the SPA
unit out and unplug the white connector from the wiring harness.
Next, drill the center hole in the aircraft panel out to 7/16”. Then drill
the two outer holes to 9/16”, then use template to mark the position
of the final two holes and drill. Finally mount the SCI-S chassis
(see Figure 2):
1. Remove the knobs from the Volume and Squelch controls using
a 0.050” Allen wrench. NOTE: DO NOT REMOVE the nuts from
the Volume/Squelch (VOL/ SQ) or ALL/ISO/CREW controls.
2. Insert the SCI-S unit from the rear of the aircraft panel with the
appropriate arrow on the unit chassis pointing upwards. The
squelch indicator lights (LED’s) should easily fit through their
respective holes.
3. Install the printed SCI-S panel and lightly thread the two 4-40
screws through the holes in intercom panel. The nuts on the
Volume/Squelch and ALL/ISO/CREW controls should fit inside
the aircraft panel holes.
4. Tighten the two screws. Make sure LED’s have unrestricted
movement in aircraft panel holes.
5. Put the knobs on the Volume and Squelch control shafts and
tighten the Allen screws.
Wiring Change
The wiring changes to an existing SPA installation are as follows.
Re-wire the pilot, co-pilot, and passenger(s) headphone lines. You
will not need the 4-foot Intercom/Aircraft interface cable (12 or 15
pin) that comes with the SCI-S system. You will use the SPA harness already in the aircraft and the 4-foot Headphone/Music interface cable (12 pin).
In a SPA installation, the tip terminals of the pilot, co-pilot, and passenger headphone jacks are wired to the blue wire (pin 3). They
need to be disconnected from there, the mono headphone jacks
need to be replaced with the supplied stereo headphone jacks
and connected to their respective pins on the Headphone/Music
interface harness. (See Figure 4 on page 3) Make sure that the
blue wire (pin 3) is still connected to the tip of the radio headphone
line.
INSTALLATION CHECK-OUT AND ADJUSTMENTS
After the unit is installed, again check that the SCI-S unit chassis,
jacks, and wiring harness are clear of all aircraft operating controls
and cause no interference with them. Next, to check out the SCI-S
unit installation plug in all the headset mic and phone plugs into the
respective intercom jacks. Put on the pilot’s headset and position
the boom mic close to the mouth, as is the practice with a handheld mic. Voice clarity is best when the mic is at one side of the
mouth and 1/4” from the lips.
To assure that the aircraft radios, pilot’s headset, and PTT switch
are connected and functioning properly, remove power to the SCIS by pulling intercom circuit breaker. If applicable, set the aircraft
audio panel to “Headphone” position. Then turn on the aircraft
radio(s) as usual, and verify that the pilot can hear the radios and
can transmit using his push-to-transmit switch and headset. Aircraft
radio(s) and audio panel should operate exactly as they did before
the SCI-S system was installed. Aircraft radio reception should not
be heard in the co-pilot or passenger headsets. There should be
no intercom between headsets without power applied to the SCI-S
unit.
Next restore power to the SCI-S unit. Switch ALL/ISO/CREW
control to the “ALL” position. Set the SCI-S volume controls to
mid-position. Set both SCI-S squelch controls fully clockwise. Pilot
can operate the aircraft radio(s). In this mode all headsets on the
intercom will hear the aircraft radio(s).
It may be necessary at this time to adjust the SCI-S unit mic output
to the aircraft radios. A small adjustable potentiometer is provided
inside the unit for this purpose. It is accessible through a hole in
the side of the SCI-S chassis. It is marked “Mod. Adj.”, and can be
adjusted with a small blade screwdriver. In the event of over-modulation (garbled) or reports of weak transmissions over the aircraft
radio, an appropriate adjustment can be made. Clockwise rotation
increases the output level to the aircraft radio mic input. Counterclockwise rotation decreases modulation level. This adjustment
sometimes needs to be made after the initial installation of the
intercom or if a new radio is installed. (The output is set for unity
gain at Sigtronics).
It may also be necessary to adjust the SCI-S unit radio receive
input from the aircraft radio. A small adjustable potentiometer is
provided inside the unit for this purpose. It is accessible through a
hole in the side of the SCI-S chassis. It is marked “RX Adj.”, and
can be adjusted with a small blade screwdriver. In the event of low
aircraft radio volume in the “ALL” or “CREW” mode relative to “ISO”
mode, an appropriate adjustment can be made. Clockwise rotation
increases the input level to the SCI-S radio receive input. Counterclockwise rotation decreases input level. This adjustment sometimes needs to be made after the initial installation of the intercom
or if a new radio is installed that has a low output impedance or low
output power. The adjustment is best made with the pilot and copilot headsets plugged in. (The input is set full CCW which is unity
gain for 500Ω radios).
You are now ready to check for proper wiring of the music sources.
First, make sure both squelch lights are off and intercom is in ALL
mode. Turn on the crew music source and listen for music through
pilot and co-pilot headsets. There should be music. Then switch to
CREW mode. There should also be music in both pilots’ headsets.
Similarly, turn on the passenger music source. There should be
music in the passenger headsets.
If everything checks out, refer to the MODE SELECTION and
AUDIO PRIORITY TABLES below as well as the separate SCI-S4/
SCI-S6 OPERATING INSTRUCTIONS sheet for proper use and
other operating modes of the Sigtronics SCI-S intercom system.
If something does not work as described, carefully go over the intercom wiring again. If something is still not right or you have any
questions regarding the installation and operation of the Sigtronics
SCI-S intercom or any other Sigtronics product feel free to contact
us directly or email us at [email protected] Technicians are
available Monday though Friday 8 am to 4:30 PM Pacific time.
This concludes the installation check-out.
SCI-S4/SCI-S6 MODE SELECTION TABLE
MODE
PILOT HEARS
CO-PILOT HEARS
PASSENGERS HEAR
ALL
ATC, Crew ICS, Pass ICS,
Crew Music
ATC, Crew ICS, Pass ICS,
Crew Music
ATC, Crew ICS, Pass ICS,
Pass Music
ISO
ATC
Co-pilot ICS, Pass ICS,
Crew Music
Co-pilot ICS, Pass ICS,
Pass Music
CREW
ATC, Crew ICS,
Crew Music
ATC, Crew ICS,
Crew Music
Pass ICS,
Pass Music
page 5
Stereo Headsets
SCI-S4/SCI-S6 AUDIO PRIORITY TABLE
MODE
ALL
AUDIO
ISO
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 modification. Contact Sigtronics for details. In general, headsets with
speakers of high and low impedance and/or unmatched audio efficiencies should not be used together without modifications.
CREW
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
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 enjoyment. 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.
CREW MUSIC **
Pilot PTT, Co-pilot
Co-pilot PTT, Co-pilot
Pilot PTT, Co-pilot
PTT, ATC, Crew ICS,
ICS, or Pass ICS
PTT, ATC, or Crew ICS
or Pass ICS
PASS MUSIC **
Pilot PTT, Co-pilot
Co-pilot PTT, Co-pilot
PTT, ATC, Crew ICS,
ICS, or Pass ICS
or Pass ICS
Passenger ICS
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 performance. 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 headphone plugs. (Only monaural music will be heard.)
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.
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.
** 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 better in this case.
Sigtronics Corporation
178 East Arrow Highway
San Dimas, Ca 91773
(909) 305-9399
www.sigtronics.com
...when it counts!
SCI-S-INSL
page 6
REV C
1-8-2007
P/N 700112
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