Telex AIRMAN 8+ - Speaker Sensitivity and Frequency Response Verification; Validate Continuity from Plug to Boom-Side PCBA; Validate the PCBA

20 en | Maintenance AIRMAN 8+
2024-11 | 07 | F.01U.387.060
Customer Maintenance Manual
Bosch Security Systems, LLC
5.4.1 Speaker sensitivity and frequency response verification
i
Notice!
This headset was designed, tested, and approved to FAA TSO C139a. The TSO requires the
headset meet the minimum performance specifications as defined in RTCA DO-214A. This
document and specifications listed here reference the test procedures, product settings,
and equipment used as defined in these standards. Refer to the standard for details on how
to perform individual tests.
All models tested, unless noted otherwise.
Transducer Type: Dynamic
Impedance (at the earphone plug): 600 Ω ±20% @ 1kHz
Sensitivity: 92 dB ±5 dB SPL (normal)
98 dB ±5 dB SPL (high)
Frequency Response: < 15 dB max. to min. over the range 315 to 3150 Hz
Volume Adjustment Setting Normal
Table5.2: Speaker sensitivity and frequency response
5.4.2 Validate continuity from plug to boom-side PCBA
To validate continuity from the plug to the boom-side PCBA, do the following:
1. Using an Ohmmeter, place one probe on the tip terminal of the PJ-055 plug or pin 1 of
the XLR plug.
2. Place the other probe at J5 on the PCBA.
3. Record the measurement.
4. Using an Ohmmeter, place one probe on the sleeve terminal of the PJ-055 or pin 2 of
the XLR plug.
5. Place the other probe at J2 on the PCBA for models -0210 and -0211 or on J6 on the
PCBA for models -0212 and -0214.
6. Record the measurement.
– If the reading is approximately zero, continuity is good.
– If any other reading is seen, the continuity is bad. Replace the cable.
5.4.3 Validate the PCBA
To validate the PCBA, do the following:
1. On the boom side PCBA, supply a 1 kHz sine wave, 1Vrms signal between J5 and J2 for
-0210 and -0211, J5 and J6 for -0212 and -0214.
2. Verify the ANR switch is in the off position.
– If a signal is heard from both speakers, the boards, speakers and wiring are good.
If no sound is heard from one or both speakers, a speaker or the wiring is bad.
Determine if a speaker needs to be replaced or the wires need re-soldering.
– If no sound is heard from one or both speakers after the above step, one or both
boards are not good and should be replaced.