Functional Test; Functional Test Of The Headphones; Functional Test Of The Microphone - Sennheiser HME 26-600 Service Manual

6

Functional test

See also:
- See "Cable and connector assignment", page 21.
- See "PCB of the acoustic units of the HMDC 26", page 22.
- See "PCB of the acoustic units of the HMD/HME 26", page 23.
6.1

Functional test of the headphones

STEP
Via AF generator supply 1 kHz/100 mV eff ± 5 mV
to the related pins of the cable´s connector.
See "Cable and connector assignment", page 21.
Put on the headset
6.2

Functional test of the microphone

Audio amplifier
OUT IN
Signal Signal
HEADPHONE MIC
Power supply
8 to 16 V DC
STEP
When testing with pre-polarized microphone of the HME 26:
Suppy the additional P48 voltage (48 V
Connect the headphone connector of the headset´s connecting
cable to an output of the audio amplifier.
Connect the microphone connector of the headset´s connecting
cable to an input of the audio amplifier.
Connect the oscilloscope´s test cable to an high impedance output
of the audio amplifier.
Put on the headset, adjust the microphone to the correct position
and speak into the microphone
Oscilloscope
Multimeter
25 µF
220 Ω
470 Ω
Microphone +
Microphone -
Headphone +
Headphone -
).
DC
RESULT
You can hear the clear 1 kHz signal without any distortions
at the left and right capsule.
2.54 cm
(1" )
RESULT
You can hear your speech without any distortion at the left and
right capsule.
The amplified audio signal of your voice will be displayed at the
oscilloscope. This visualization is helpfully for the functional test
of the microphone, e.g. trouble shooting.
HMD/HMDC/HME 26 Broadcast
08/2011 19/23