The H-143 type, Dynamic Earphone is a moving coil type earphone designed for use in a headband type headset or specific flight helmets, it also has ground crew support applications. The intended use is to provide audio communications under high noise conditions found in military, civilian and general aviation environments.
It is designed and constructed from quality durable high strength Polycarbonate plastic as well as corrosion resistant metals meeting or exceeding the environmental.
Baseline Performance Characteristics:
Frequency response range
100 to 5000Hz
Sound pressure level
91± 3db SPL /0.1W/10cm at 1KHz,Input 1.378Vrms
19 ohms or 300 ohms ±15％ohms @1KHz 1Vrms
-20℃ to + 60℃
-20℃ Duration: 96 hours
+60℃ Duration: 96 hours
Less than 5％ at 1KHz 0.1W/10cm
Input power 0.8W pink noise 48 hours
Humidity test: Temperature
90% ~ 95%
48 hours (recovery 6 hours)
Drop it no to concrete surface in 3 directions
Cycle: 10 cycles
Frequency: 1800 cycles/min.
Duration: 1 hour in each of 3axes
Terminal strength test
Load 1.5 Kg
Duration: 15sec (shall be normal)