UK US Nato headset plug
 

Hi,
Ive been trying to find the wiring diagram for the UK and US Nato headset plug, i know its only a couple of wires switched around but i cant seem to find one.
And the size difference for the two types of heli plug that are available.
Would anyone out there have a link or a diagram they could email me please??
Cheers Lee...

Rather than email, could we post here... :)

I have a perfectly good helmet on which the microphone doesn't work. It'd be useful to know the pin-outs before I wreck the thing with 3rd-rate electronics knowledge... All that google has brought me in the past is endless offers of NATO UK-US adapters and 1 definitely incorrect diagram.:ugh:

Thanks for any pointers.

Hi, Guy's

Pin 1 = Microphone Positive
Pin 2 = Headphone Positive
Pin 3 = Microphone Earth
Pin 4 = Headphone Earth

Pin 1 is the tip of the plug, pin 4 being the base ring.

Will look out a PDF tonight that has all the different versions on it.

Regards

Kevin.

US Nato (silver)
Tip 1 Mic ground
2 Audio +
3 Mic +
4 Audio ground

UK Nato (bronze)
Tip 1 Mic +
2 Mic Ground
3 Audio +
4 Audio ground

http://www.mobileone.com.au/headset/...-174-u-300.jpg
U-174/U (TP-101)
HELICOPTER HEADSET / HELMET PLUG
. This is NOT a NATO plug, it is a NEXUS plug (sometimes referred to as a US NATO plug) and it is not compatible with the UK NATO plug below. TheU-93/A (TP-102)plug is the same mating shaft with a larger back shell for thicker cable. Wiring,
Tip(1) Mic low (2) Ear high (3) Mic high (4) Ear low

http://www.mobileone.com.au/headset/...o-plug-300.jpg
PLUG 671
UK or EUROPEAN NATO PLUG
This plug will not mate with the Nexus range, the mating shaft diameter is 0.4mm bigger. This is a Mil spec brass plug, NSN:5935-99-946-6652. Wiring, Tip Mic, Ring 1 Mic, Ring 2 Ear, Ring 3 Ear, (Ring 1 next to tip) Mating socket, Socket 626, NSN:5935-99-949-1940

Bang on. That's just what I wanted. Thank you very much, everyone. :ok:

Thank you very much..

Lee...

Many years ago when I went to ETPS, I was more than slightly surprised to learn that I couldn't plug my Canadian / US style helmet into a British helicopter. So much for NATO standardization....
Then I went to work at the US Naval Test Pilot School and couldn't plug US Navy helmets into other US Navy helicopters...

Just like there is no NATO definition of what a standard stretcher for medevac is....

Back in the early eighties I recall that a British Army standard GS stretcher only fitted in the Lynx stretcher fit Cradle (I think it could take three, one above the other, diagonally)! If you cut about 3 inches off each stretcher handle!:rolleyes:

Funny about the Lynx - that's where I found out there was no NATO standard stretcher.
Seems like the Army / Navy requirement for the Lynx called for it to be able to carry a NATO standard stretcher. The Lynx dimensions were also being very heavily defined by the military, resulting in a problem. How to get the stretcher into the cabin. Someone clever in Westlands discovered there was no NATO definition - everyone was using the US military stretcher size by default without it being written down, it seems. So they were able to get out of the requirement - a US stretcher will fit diagonally, it seems. The UK then somehow adopted the Neil Robertson (name may be wrong) stretcher, which was basically strengthened cardboard with no bracing to make a flat surface. when you picked someone up, the thing basically curled around the body.
Worked OK unless you had a shoulder or back injury, as happened to the first F-18 accident pilots who happened to land next to Middle Wallop and get picked up in those stretchers...
(sorry - I know this is off-thread, but it shows the issues of interoperability)

Currently fly two different civil machines... one uses a U-174/U into a high-impedance audio system, the other uses a NATO plug into a low-impedance audio system. Try that with a Bose X. This is why the answer to this question was readily available. The complexity'd make you weep, it truly would.:{

Yeah, frustrating,

My helmet works perfectly in two new Canadian Schweizer 300's, but when I plugged into a Canadian H500D, it would not work. I had to have the ramp attendant quickly swap my helmet for a headset, as we were already running.

Pilot DAR

Impedance...
 

Folks,

Regardless of the plug, there are basically two impedances used on audio systems i aircraft. One correpsponds to using a dynamic microphone, one to an elecret type. Best thing to have in your helmet is a dynamic microphone (better sound quality, generally) and a switchable adapter. Apart from the plug diameter, this will make it work in all audio systems. The amplifier is a simple little thingy with one transistor and a few other components.

Dynamic
~ 250 ohm Impedance
Usually differential, which means that it has a natural noise cancellation for sound coming in equally on the front and the mouth end of the membrane.

Elecret
~ 5 ohm impedance
Needs power supply from intercom. Smaller in size. Sharper in sound, rough at the high end.

Also, if you experience problems with sound levels in the passengers' ears, try using exactly the same model headsets for all passengers as they are usually connected in parallel. Good old units like the KMA24-series also run the co-pilot in parallel with the passengers when the pilot isolates himself and the co-pilot ends up chatting with the passengers.

Just my two bucks worth (inflation).

/p

Dynamic to electret amp 1 transistor,
Wont post, back to drawing board so to speak:*

Very old post I know, but I came across it and there are a couple of errors.
There are 3 main microphone types used on aircraft:
1/ Amplified or "carbon compatible". These are used on the majority of light aircraft and civil aircraft. They are replacements for the earliest carbon microphones and require a DC energising voltage (8-15V in series with about 500 ohms)
Headsets with these typically have two separate plugs. Some newer airliners us multipole "XLR" types. The actual microphone element, may be dynamic or electret depending on the design. As it's amplified the system doesn't care. The output voltage is high, hundreds of millivolts
2/ High impedance dynamic. Used on UK / European military aircraft and some North American military. These are dynamic or moving coil microphones with an impedance of around 200 Ohms. Medium output around 100 millivolts. No DC voltage required. Basically the same as used on land radios. Typically a brass 4 conductor "UK" NATO plug.
3/ Low impedance dynamic. Used on North American military aircraft. Impedance is about 5 Ohms. Low output of around 100 microvolts. Not used much elsewhere.
You can adapt a high impedance dynamic microphone to use on a carbon compatible aircraft using a simple 1 transistor amplifier. This is powered by the system.
You can use a high impedance dynamic on a a low impedance system with a transformer or even a resistive attenuator.
You can adapt a low impedance dynamic to work on a carbon or high impedance using an amplifier (different gains for the two systems. This will need external power (batteries) for low impedance and may need the for cabon.
Summary: Low impedance Dynamic is a right pain to work with.