ALPS face mask and the B0se headset.
Nasal-oral face masks 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 face mask 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 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) and has a better than 3 dbm variation throughout 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.
