Sigtronics SRE-4 - Manual (Page 2)

INSTALLATION INSTRUCTIONS: Please read the following instructions carefully
PLUG
PIN NO.
WIRE
COLOR
FUNCTION CONNECT TO:
PLUG
PIN NO.
WIRE
COLOR
FUNCTION CONNECT TO:
1 White/Black Left Mike Input
Ring Terminal of Intercom Left
Mike Input Jack
11 White/Orange Right Mike Input
Ring Terminal of Intercom Right
Mike Input Jack
2 White/Red Left Transmit Switch Input Left Transmit Switch 12 No Connection
3 Violet Squelch Control Input
Clockwise Pin of Squelch
Control
13 Gray Headphone Output All Intercom Headphone Jacks
4 Black Ground Aircraft Chassis Ground 14 Blue Radio Headphone Input
Aircraft Radio Headphone Output
Jack
5 White
Transmit Relay Control
Output Tip Terminal of Aircraft Mike
Input Jack
15 Tan Rear Mic Jack Ring Terminal of Rear Mic Jack
6 Brown Mike Output Ring of Aircraft Mike Input Jack 16 Tan Rear Mic Jack Ring Terminal of Rear Mic Jack
7 Red Power Input Radio Circuit Breaker
8 Orange Volume Control Output Volume Control Wiper
9 Yellow Volume Control Output Volume Control Clockwise Pin
10 White/Blue Right Transmit Switch Input Right Transmit Switch
NOTE: Connect the CCW Pin of the Volume Control to Intercom System Ground.
Connect the CCW Pin and Wiper of Squelch Control to Intercom System Ground.
Connect one terminal of push-to-talk switch to Aircraft Chassis or Intercom System Ground.
Aircraft Chassis Ground.
Intercom System Ground.
TABLE 1
CHASSIS INSTALLATION
Your TRANSCOM has been supplied with the necessary
hardware to mount the Chassis to the aircraft.
Four grommets are installed in the Chassis bottom, in-
tended for mounting.
Four 6/32” screws with self-locking nuts have been pro-
vided for mounting.
1. Remove the four corner panel screws from the unit.
2. Remove the unit from the case.
3. After selecting a suitable mounting location in the aircraft,
drill aircraft with the same hole pattern as in the intercom case.
Use a No. 27 drill (Clearance drill for 6/32”).
4. Secure case to the aircraft with the screw heads inside inter-
com case for circuit board clearance. (Care should be taken not
to crush the grommets while applying torque to the screws.)
5. Replace the unit in the case and secure.
WIRING INSTRUCTIONS
Your TRANSCOM has been supplied with four feet of cable
to connect the unit to the aircraft.
Figure 2 illustrates the connection to be made.
Table 1 lists the connector plug pin numbers, the color, function,
and destination of each wire connected to those pins.
Connections should be made as shown in Figure 2 and as indi-
cated in Table 1. Sigtronics should be contacted if other means of
connecting the unit are contemplated.
NOTE:
1. Care should be taken to verify that the aircraft radio wiring
conforms to the standard color code.
2. The Squelch and Volume Control shafts should be cut to
length after installation plan is complete.
3. To avoid ground loop induced noise, the microphone,
volume control and squelch control grounds should be floated and
returned to the unit ground. The unit ground, in turn, should be
carried close to the aircraft mike input jack ground.
4. A small, square, white or gray trimmer potentiometer is
provided inside the unit for adjusting the mike input level to the
radio. In the event of overmodulation or reports of weak trans-
missions, an appropriate adjustment can be made. Clockwise
rotation of the screwdriver adjustment increases the mike output
level.
REM 1027A
REAR
HDPH
JACKS
REAR
MIC
JACKS
TAN
TAN