gadgeto

Hi folks,
I'm trying to build an adaptor for my nokia (cable) headset to work with my x51v. (from 2.5mm to 3.5mm)
I've got all the material (at last) but I need to know the precise pinout of the 4-contact headphone jack in the Axim.
Can anyone help me? Any pointer?
(I also need the Nokia part but I guess that will be easier...)

Thanks a lot.
Gadgeto

AKAJohnDoe

4-contacts? Really? I hadn't looked lately, but did not think that headphones had changed much since stereo was introduced in the 1950's with the 3-contact 1/4" phone plug. I would expect that Radio Shack would have the adapter in stock.

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gadgeto

Yep, 4-contact
I haven't found it at Radio Shack's site, furthermore I have not found a spare 2.5mm 4-contact female jack, So I have taken one from an old nokia phone...

AKAJohnDoe

I suppose a headset would have the need to be bisync (to avoid the old walkie-talkie effect of only having one person being able to speak at once), plus the microphone and speaker circuitry. Could add up to 4. You should be able to isolate the mike and leave it unconnected.

I used a set of old Koss headphones as a microphone once in the early 1970's out of neccessity.

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bigbop

Originally Posted by AKAJohnDoe

4-contacts? Really? I hadn't looked lately, but did not think that headphones had changed much since stereo was introduced in the 1950's with the 3-contact 1/4" phone plug. I would expect that Radio Shack would have the adapter in stock.

Looking at the picture above, instead of Left, Right, Ground, you will have Left, Right, Mic, Ground.

I already built an adapter using the 4 circuit plug and it works fine.

Typically on a computer mic, it may have a stereo plug but the two circuits for L & R are usually connected, so you will need to make sure that you use a stereo jack for the mic and connect the L & R together.

tancerman

Originally Posted by AKAJohnDoe

4-contacts? Really? I hadn't looked lately, but did not think that headphones had changed much since stereo was introduced in the 1950's with the 3-contact 1/4" phone plug. I would expect that Radio Shack would have the adapter in stock.

Yes they do have these at radioshack. I am thinking of buying it so I can use my sch-a970 with regular headphones. http://www.radioshack.com/product/in...entPage=family

puntloos

Any update on this? As long as you can find a 4-pin connector Im sure any amateur techie can wire this up him/herself.

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aNTiCRoMBie

Originally Posted by bigbop

Looking at the picture above, instead of Left, Right, Ground, you will have Left, Right, Mic, Ground. I already built an adapter using the 4 circuit plug and it works fine. Typically on a computer mic, it may have a stereo plug but the two circuits for L & R are usually connected, so you will need to make sure that you use a stereo jack for the mic and connect the L & R together.

Did you build an adapter that would include stereo out and mono mic in? I am trying to build such an adapter for my pda/phone, and am having trouble finding a pinout for standard 3.5mm stereo plugs. Any suggestions on where to look?

bigbop

Originally Posted by aNTiCRoMBie

Did you build an adapter that would include stereo out and mono mic in? I am trying to build such an adapter for my pda/phone, and am having trouble finding a pinout for standard 3.5mm stereo plugs. Any suggestions on where to look?

There's only 3 connections; gnd, left & right
Your problem is that you need to find out what your specific pda has for an output. If the jack has mic input, then does it use mono out or does it have a 4 circuit jack like the x50?

rickdm

Originally Posted by gadgeto

Yep, 4-contact I haven't found it at Radio Shack's site, furthermore I have not found a spare 2.5mm 4-contact female jack, So I have taken one from an old nokia phone...

Here is a site that will have the 4 position plug that you a re looking for. You are going to have to do some pretty fine soldering and make your own "molded connector" when done. These are generally used by manufactures who will then make a olded cable from them.

I purchased some of the 2.5 mm extended plugs (the type used on frs radios for the headsets) last year and they are of excellent quality. I made the solder connections to the jacks and plugs and then molded the connections in some 2-part epoxy for both insulation purposes and to hold it all together.

http://www.connect-tech-products.com...m%20Plugs&id=2

Check out this site. They were the only place after about a month of searching the web that had what I needed. You're not going to find a 4 position plug at :scratch_h "You've got questions? We've got blank stares!":scratch_h Radio Shack.

Hope this helps
Rick

dschmider

http://pc-mobile.net/ax50.htm

code: PX50MS (2nd from bottom)

gadgeto

Originally Posted by dschmider

http://pc-mobile.net/ax50.htm code: PX50MS (2nd from bottom)

Thanks dschmider,
but what I was looking for was a one-jack adaptor from 4-contact 2.5mm female to 3.5mm male, in order to use my cell phone's headset.

regards,
Gadgeto