JA98-001 Remote Mount Audio Controller
Installation and Operating Manual
Rev A
Page 7
MIL-C-27500 shielded wire with tag ring or equivalent (for shield terminations) to make the most compact and easily
terminated interconnect. Follow the Connector Map in Appendix A of this manual.
Allow 3” from the end of the shielded wiring to the shield termination to allow the connector hood to be easily installed.
Refer to the Interconnect drawing in Appendix A of this manual for shield termination details. Note that this unit has a
‘clamshell’ hood that is installed after the wiring is complete.
Maintain wire segregation and route wiring in accordance with the original aircraft manufacturer’s maintenance
instructions.
Unless otherwise noted, all wiring shall be a minimum of 24 AWG, except power and ground lines, which shall be a
minimum of 22 AWG. Refer to the Interconnect drawing for additional specifications. Check that the ground
connection is clean and well secured, and that it shares no path with any electrically noisy aircraft accessories such
as blowers, turn-and-bank instruments, or similar loads.
2.4.3
Mechanical Installation
The JA98-001 can be mounted in any attitude and location with sufficient clearance for the connector and wiring
harness. It requires no direct cooling.
2.4.4
In-Line PTT Cordsets
If in-line PTT cordsets (drop cords) are used, be aware that incorrectly configured or improperly shielded in-line PTT
cordsets can lead to significant audio problems.
2.4.5
Post Installation Checks
2.4.5.1
Voltage/Resistance checks.
Do not attach this unit until the following conditions are met:
a) Check P2 pin
17
for +28 Vdc or +14 Vdc relative to ground.
b) Check P2 pin
34
for continuity to ground (less than 0.5
Ω
).
c) Check P2 pins
6 thru 1
2
for continuity to ground (less than 0.5
Ω
) when the relevant switch is closed.
d) Check P12 pins
6
for continuity to ground (less than 0.5
Ω
).
e) Check all pins for shorts to ground or adjacent pins.
2.4.5.2
Configuration
Ensure that the JA98-001 contains the correct configuration settings. This may be done at the factory, on the
maintenance bench or in the aircraft before the power on checks are performed. Refer to
section 2.5
.
2.4.5.3
Power on Checks.
Power up the aircraft’s systems and confirm normal operation of all functions of the JA98. Refer to
Section 3 (Operation) for specific operational details.
a) Begin with only the pilot’s headset attached. Confirm correct ICS and radio operation for both receive and
transmit. Check yoke or cyclic switch action. Check the radio selection and inputs. Do not proceed until the
radios are functioning correctly.
b) If there is a music source in the system, turn it on and check for proper mute operation.
c) Unusual buzzes, hums or other background audio are symptomatic of multiple grounds, or noisy external
systems such as blowers or pumps sharing wiring with the audio system. If a transmitter fails to key or
correctly modulate it is often the result of not connecting all required grounds to the radio or external audio
system.
d) Check the ICS operation and Emergency operation.
e) Plug in the co-pilot’s headset. Check for correct ICS operation. Check yoke or cyclic switch functions.
