Helicopter plug issue

[Escape Path]

Hello.

I bought a Bose A20 headset with a U-174/U plug. Although my aircraft is a Twin Otter it has a helicopter socket, the U-92A/U. The thing is, though, when I plugged it in this morning, I couldn't get any sound off the mic; not on the PA, not to ATC either. The airplane's DC headset worked with no problem (for the whole 7:31 I flew :* ). The headset seems to be receiving sound though, as I could hear the other pilot through the headset.

The question is: What am I doing wrong? What am I missing? Do the plugs match or do I need an adapter?

Thanks in advance

[rjtjrt]

I am electronically illiterate so this may be totally wrong.
Could it be the difference between US NATO plug/socket vs UK NATO plug/socket?
See http://www.pprune.org/rotorheads/303546-uk-us-nato-headset-plug.html

John
PS Could there be a more blatant example of bloody useless national bloody mindedness than the US vs UK NATO plugs being wired differently! (I obviously like the word bloody!).

[IntheTin]

I think the low impedance doesn't come with the Bluetooth feature like the high impedance.

[Escape Path]

Hi all.

Thanks for the replies. I didn't get the bluetooth option.

What does that means then? Do I need to change the boom? :confused:

EDIT: By the way, the David Clark headset plug fits perfectly into the socket, but somehow my headset plug seems to pull back just a little bit and if I held the plug and the socket together, the mic still doesn't work.

Regards

[Senior Pilot]

Escape Path,

Maybe a read of these threads may help?

What impedance is best is best for what aircraft? (http://www.pprune.org/rotorheads/279205-what-impedance-best-what-aircraft.html)

This post (http://www.pprune.org/6069061-post358.html) in the Helmets thread

Impedance matching (http://www.pprune.org/rotorheads/431884-impedance-matching.html)

Or search "Bose":

New Bose A20 headset (http://www.pprune.org/rotorheads/422854-new-bose-a20-aviation-headset.html) :ok:

[Escape Path]

Thanks all for the replies.

@Um...Lifting...: I removed the foam cover and I couldn't find any figure about the impedance. The mic shape however, matches your description of a low impedance mic.

I just talked to the guy who does the avionics at my airline (there are a handful of pilots with the same headset, different plug though) and he says the mic is the correct one (impedance-wise) and that the problem might be the polarity. He reckons (by verbal diagnosis though) that by inverting the polarity of the mic the problem will be solved. I'm gonna see him tomorrow and hopefully he'll get them working. I'm dead tired of flying with those knackered DC's :*