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KC2UGV
10-11-2010, 05:41 PM
... that I got from my "Mil surplus" storage unit (ie, my closet of stuff I haven't touched since I left the service in 2004).

I happened across lots of goodies. A 12V power supply, a 3-30MHz WSR/Power meter, etc. But, what caught my eye is my old aviation headset.

This is the data sheet on it: http://www.wbparts.com/rfq/5965-01-121-2319.html

I remember wearing that thing for 14 hours a day on end. Comfortable as all hell. But, the question is: Can I use this on my rigs now?

It has a 1/4" TRRS connector. I assume this is a somewhat "standard" plug in aviation. Any tips? How do I wire this thing up? Will it work ok?

NQ6U
10-11-2010, 05:49 PM
But, the question is: Can I use this on my rigs now?

It has a 1/4" TRRS connector. I assume this is a somewhat "standard" plug in aviation. Any tips? How do I wire this thing up? Will it work ok?

There was an article on using aviation headsets in a QST magazine a few months back. I remember it because I have a pair of David Clarks that I'd like to use in my station. According to the article, it's doable with a bit of extra circuitry. I'll try and find it and scan the schematic for you.

WØTKX
10-11-2010, 08:14 PM
Just wire it up to whatever plug is needed, most headphone/speaker jacks will work FB from 4-16 ohms. Unless it's wired weird.

NQ6U
10-11-2010, 08:24 PM
Just wire it up to whatever plug is needed, most headphone/speaker jacks will work FB from 4-16 ohms. Unless it's wired weird.

As I recall, aviation headsets are high-impedence. 600 ohms, I think, although I could be wrong about the actual number.

KG4CGC
10-11-2010, 08:30 PM
As I recall, aviation headsets are high-impedence. 600 ohms, I think, although I could be wrong about the actual number.
I'd look for a simple transformer or op amp.

NQ6U
10-11-2010, 08:31 PM
I'd look for a simple transformer or op amp.

The circuit I was thinking about used an op amp.

KG4CGC
10-11-2010, 08:41 PM
The circuit I was thinking about used an op amp.
Good call!
Mas Tequila?

http://i25.photobucket.com/albums/c79/bebop5/drinks/giant-margarita-glass-70007-1.gif

kb2vxa
10-11-2010, 09:06 PM
No need for fancy stuff, transistors being current devices easily tolerate high impedance loads, even no load won't trouble it. In other words a 600 ohm headset will work just fine, my vintage B-29 headset does. Oh, they hate very low impedance loads being Ohm's Law takes over and excessive current overheats them and POOF, bye bye output stage, the chip is toast.

n0eq
12-25-2010, 02:46 PM
I use a David Clark Helicopter headset with my Yahoo 857.
Replaced the 4 conductor phone plug with a 1/4" TRS.

Earphones work fine with whatever impedance match/mismatch there might be.

The 5 ohm dynamic mic is a little whimpy. I got it to work well with a RatShack
audio transformer which is normally 1000 ohm CT, 8 ohm secondary. I reversed
it and used half of the CT to allow the 8 ohm side to marry the 5 ohm dynamic
element, and the 500 ohm side (1000 ohm CT) to marry the 600 ohm input to the radio.

Even though that worked great, I put a cheap elec condensor mic element
on the surface of the existing headset mic and ran that to a little preamp
to give the condensor some bias. That setup works fabulously. The mic
element is simply held in place by the foam and leather bits on the "Phoenix"
noise reduction parts. And instead of that heavily compressed, close
mic "aviation sound" I get a great, full range, audio Hi Fi sound on
HF and VHF.

Photos on my website -


Craig 'Lumpy' Lemke
www.n0eq.com (http://www.n0eq.com)

WØTKX
12-25-2010, 06:49 PM
Yup, I read 5 Ohms, from the spec sheet.


IMPEDANCE RATING 5.0 OHMS NOMINAL

You could make measurements, and stuff... http://www.cliftonlaboratories.com/headphone_impedance.htm (http://www.cliftonlaboratories.com/headphone_impedance.htm)

kb2vxa
12-26-2010, 06:01 PM
Lumpy has the right idea but I'll add one thing. If you don't want to destroy a perfectly good cord and plug I have the jack for you. An ohm meter will identify the phone, mic and PTT connections, I strongly suspect shell is as usual the common ground.

http://www.edmo.com/index.php?module=products&func=display&prod_id=20220&cat_id=

KC2UGV
12-26-2010, 07:24 PM
Lumpy has the right idea but I'll add one thing. If you don't want to destroy a perfectly good cord and plug I have the jack for you. An ohm meter will identify the phone, mic and PTT connections, I strongly suspect shell is as usual the common ground.

http://www.edmo.com/index.php?module=products&func=display&prod_id=20220&cat_id=

You da man! TP-101 is the jack nomenclature :) Thank you!!

kb2vxa
12-27-2010, 09:01 PM
Oh you're welcome, when I thought you were going to murder an innocent headset I had to do SOME-THING.

KC2UGV
12-27-2010, 09:10 PM
Oh you're welcome, when I thought you were going to murder an innocent headset I had to do SOME-THING.

And, now that I had that information, I pull the headset out of it's case, and lo and behold: The Jack's nomenclature is on a label affixed to the cable :duh: