10
All of the E.I. Instruments listed in the AV-17 16-Pin Connector Chart have an External Warning Control
Line. This line is a white/yellow wire. This wire pulls to ground when a specific condition occures, thereby
activating the appropriate AV-17 Voice Warning. For more information regarding conditions which activate the
External Control Line on a specific E.I. Instrument, please refer to the appropriate Instrument Operating Manual.
Note:
The Check Bus Voltage control line is built into the AV-17 (i.e., the AV-17 does not need to connect to
the VA-1A Volt/Amp Instrument).
All of the AV-17 control lines have high input resistance and will not affect any device to which they are
connected. To activate a specific AV-17 voice warning, the appropriate control line must be pulled to ground
(grounded). If a positive voltage is required to activate a specific voice warning, an AVI-1 Inverter must be wired
in series with the appropriate AV-17 Control Line as shown below.
Connect to
Warning Device
(positive when
alarm is activated)
Black Wire
Brown Wire
White Wire
Connect to appropriate
AV-17 Control Line.
Connect to ground.
AVI-1
F. AV-17 Check-out and Volume Adjustment:
1. Apply power to the AV-17. Each time the AV-17 Control Panel Switch is placed in the momentary
ACK position a Beep can be heard in the headset. If a Beep cannot be heard, perform the following:
A. Insert a small flat tip screwdriver in the hole on the side of the AV-17 Control Box and adjust the AV-
17 volume to maximum (full clockwise adjustment). The AV-17 Control Box is mounted under the
instrument panel.
B. Verify that the AV-17s ground and power wires are connected properly.
C. Verify that the orange wire (AV-17 Voice Warning Output) is connected properly. The orange wire
may be connected directly to the headset. Disconnect all other wires on the headset female connector
(tip) and connect only the orange wire. Make sure the headset female connector (barrel) is grounded.
If the AV-17 works properly, replace each disconnected wire until you find the wire which causes the
AV-17 to function improperly.
Note:
If any paralleled device or radio has a low output resistance, the AV-17 volume will be very
low. If this is the case, place a 330 ohm 1/4 watt 5% resistor in series with the output of the low
resistance warning device. This will allow both devices to operate properly.
2. Adjust the volume on the side of the AV-17 Control Box. Do not make the AV-17 volume too loud. Keep
in mind that it is possible for an AV-17 voice warning to occur at the same time the pilot is listening to a
radio message. The AV-17 Control Box is mounted under the instrument panel. Insert a screwdriver in the
hole on the side of the AV-17 Control Box to adjust the volume.
When the AV-17 is set from the OFF to the ON position, the AV-17 will announce Voice Annuncia-
tor enabled. You may want to listen to this announcement when adjusting the AV-17 volume.
