Table 1 pin wire color function connection – Sigtronics SDB-800 User Manual

Page 3

WIRING INSTRUCTIONS

Figure 4 and Table 1 show how to make the wiring connections.
If you need longer wire lengths, use good quality hook-up wire,
22 gauge or larger. Shielded audio wire can be used, however, it
is not necessary. This can simplify the wiring process.

*1. The blue wire from Pin 3 must be connected to the aircraft

radio headphone output - NOT the speaker output.

*2. Connect all intercom mike jack grounds to a single aircraft

chassis ground point - Point “A” - See Figure 4. (Use the
black washers supplied to insulate intercom mike jacks
from aircraft chassis ground).”

*3. Do NOT connect transmit switches to white (key) wire.

*4. Red wire may be connected to either 12V (I 4V) or 24V (28V)

power source. No switching or adjustments are necessary
to operate from either source.

*5. Tan wires (pins 8 and 9) and white / orange wires (pin 10)

are only used on installations that require extra intercom
positions.

**NOTE: Use this intercom central grounding point so that no unwanted
electrical noise, such as alternator whine or strobe noise, will be induced into
the intercom system through the grounds. Each intercom mike jack barrel
should be insulated from ground and connected back to Point ”A” on its
individual ground wire. Similarly, both intercom ground wires (pin 4) and the
push-to-talk switch grounds should be connected back to Point “A”. It is not
necessary, however, to connect the headphone jack barrels to Point “A”. They
can be grounded where you mount them or some place nearby.

Table 1

Wire Color

Function

Connection

White / Black

Pilot Mic Input

Ring Terminal of Pilot Intercom Mic Jack

White / Red

Pilot Transmit Switch Input

Pilot Transmit Switch (PTT) (Switch to Ground to Transmit)

Blue *1

Headphone–Radio & Intercom Output

Radio Headphone Output & Intercom Headphone Jacks

Black **2

Intercom Central Grounding Point

Aircraft Chassis Ground

White *3

Radio Transmit Key Control Output

Tip Terminal of A/C Hand Mic Jack or Key Input of Audio Panel

Brown

Transmit Mic Audio Output

Ring Terminal of A/C Hand Mic Jack or Mic Input of Audio Panel

Red *4

12 thorough 24 VDC Power Input

Intercom Circuit Breaker

Tan *5

Passenger Mic Input

Ring Terminal of Passenger Intercom Mic Jack

Tan *5

Passenger Mic Input

Ring Terminal of Passenger Intercom Mic Jack

White / Blue

No Connection

White / Orange

Passenger Mic Input

Ring Terminal of Passenger Intercom Mic Jack

Yellow

Bidirectional Intercom Link

To Other Intercom Yellow Wire

* See Wiring Instructions

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