ALPS Face mask and the BOSE headset
Nasal-oral facemasks with microphones can now operate properly with the BOSE (6 Pin LEMO) headset. Because both microphones inject into your audio system at once, you will need to switch-out the Bose microphone and switch-in the facemask microphone with this PA-100B microphone switch-over adapter. Without doing this your voice over the intercom and, most importantly, the radio will be degraded to the point that center will have trouble hearing you.
The PA-100B BOSE microphone-only switch-over adapter does nothing to the stereo earphone circuit. The Adapter has a switch (M for Mask, S for headset) that allows you to easily switch between the two microphones without fiddling with connectors.
Electro-Acoustical performance of the Alps Microphone
The Alps microphone is an amplified and buffered noise-canceling electret-condenser type. It is built into our custom housing for the ability to be fitted into the Alps mask as well as many other TSO civilian and Military type face masks. The shielded coaxial cable cable comes standard issue at ~1 Meter long. The connector is the standard ‘PL68 or M642/5-1’and can be fitted to any type of aviation style fixed or rotor-wing microphone connector.
The Alps microphone has a frequency response for voice (300~3 KHz) has a better than 3 dbm variation through out this spectrum into ~600 Ohms. The variation from microphone to microphone is better than 6 dbm.
The noise canceling mechanism is entirely mechanical providing superior reliability and is focused on the energy spectrum where wind and engine noise is most prevalent, and can tolerate a modest amount of misalignment to the mouth.
The internal amplifier and impedance buffer is designed to meet TSO-C58a and is entirely self powered from the current loop provided by any standard aircraft band radio and/or integrated communication system designed to TSO-C139 or equivalent. In many cases the Alps microphone can replace a carbon type microphone. Please email us if you should have any technical questions.