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Flying_Anorak
11th Sep 2018, 22:38
Hi Folks,

I need your advice please, I have acquired a fully serviceable Mk4 Bone Dome for use in my Chipmunk. The helmet has RAF avionics and is fitted with a brass coloured NATO plug. What adapter would I need please?

I see that various aviation suppliers offer various adapter leads, but I have also seen one that includes some form of amplifier which I'm told I would need to use to make the boom mike on the helmet work, otherwise the adapter leads would just allow me to receive but not transmit.

Anyone else out there using an RAF bone dome with standard GA avionics please?

Cheers

Paul.

Whopity
11th Sep 2018, 23:08
The RAF bone dome uses a dynamic microphone wheras the standard GA microphone is based upon the use of a carbon mic which has a DC feed. The output from a moving coil dynamic mic is considerably less than the carbon type and therefore requires amplification as well as a blocking capacitor to prevent the bone dome mic from shorting out the microphone line. A straight adapter will not work, it needs to be designed to adapt the two different types of microphone. I have a circuit diagram for an adapter if you have the ability to make one up.

Pontius
12th Sep 2018, 04:32
Talk to these people; they know their stuff:

Headset Services (http://www.headsetservices.com/gaadaptors.html)

ChickenHouse
12th Sep 2018, 09:58
You need a sufficient and adapted pre-amplifier to get a RAF bone to GA equipment and the results are highly dependent on your specific equipment and the skill of the avionics master doing the work. I have done the connection several times for warbirds, but would advice to not spend your nerves on trying to. Buy a GA headset and radio happily ever after ...

360BakTrak
12th Sep 2018, 19:19
I use this (http://www.flyingshop.com/adams-emcc-mkii-adaptor-for-matching-military-headsets-with-civil-radios/) ; expensive but great quality and does the job perfectly.

HamishDylan
30th Sep 2018, 21:06
I would try Microavionics - if they don't have something on the shelf, they are great at coming up with reasonably priced bespoke solutions.