2 receive audio, 3 emergency switch (emer/norm), 4 ics functions – Northern Airborne Technology N301A User Manual

Page 25

N301A-000 Audio Controller

SM45 Installation and Operation Manual

Section 3 Rev: 1.00

Issue 4

Page 3-2

3.3.2

Receive Audio

TX switches RX switches

COM3

COM4

COM5

COM2

NORM

EMER

ICS

RADIO

ICS

HOT

VOX

DME

MKR

ADF1

ADF2

NAV1

NAV2

RX-ON

AUX

PVT

Emergency switch

Radio volume control

Receive audio is selected by switching any of the RX or TX switches upwards to connect the indicated
radio to the headphones. All radio audio is controlled by the front panel RADIO volume control, and may
be varied to suit conditions.

The six receiver switch bats (NAV1, NAV2, ADF1, ADF2, DME, and MKR) are colour-coded blue. The six
transceiver switch bats (COM1 thru Com5, and AUX) are white.

3.3.3

Emergency Switch (EMER/NORM)

The red emergency switch can be used to route the headset (either high or low impedance) directly to the
COM1 receive audio, allowing passive operation. In units s/n 2000-2052, Direct Audio 1 is also switched
to the headset. In units s/n 2053 and above, Direct Audio 3 is also switched to the headset. The transmit
PTT requires no special switching in the emergency mode and operates as it does in the normal mode.
No intercom operation is possible in EMER mode.

3.3.4

ICS Functions