HME 46-3, HMD 46-3
02/2008
5
Testing and fault isolation
5.1
Tools and test equipment
5.2
Operational test of the audio system
References
•
see “Cable connector´s pin alignment”, page 14.
•
see “Wiring diagrams”, page 15 et sqq.
•
see “Printed circuit boards”, page 19.
5.2.1 Audio testing the headset with cable
1. Connect the sine wave generator with the negative and the positive line at the relevant pins of the
connector, see “Cable connector´s pin alignment”, page 14 or see “Wiring diagrams”, page 15 et sqq.
2. Set the sine wave generator to 300 mV eff ± 5 mV with a signal of 1 kHz and switch the generator on.
3. A clear signal without any distortion must be audible in both capsules.
5.2.2 Operational testing of the pre-polarized microphone at the headset with cable
(HME 46-3-x only)
A. Audio testing, see “Cable connector´s pin alignment”, page 14 and see “Wiring diagrams”, page 15
et sqq.
1. Connect the headset with the cable connectors into the intercom.
2. Put on the headset, adjust the microphone to the correct position and talk into the microphone.
3. Listen to the audio output signal. No distortion should be audible.
B. Visual testing
1. For detailed visual testing please use the ossiloscope, see “Microphone test setup according to RTCA/DO-
Description
Specification / Type
Source
Power supply
U: 0-30V DC adjustable
I:
≥
500 mA
eff
Hum: <1%
Commercial
Sine wave generator
AF Level adjustable
Commercial
Multimeter
U: 0-30V DC
I:
≥
500 mA
eff
Resolution
≤
0.1 V
Commercial
Oscilloscope
-
Commercial
Intercom
Audio amplifier
-
Any audio amplifier with
high impedance micro
input
Commercial
Commercial
