I needed a corded telephone with a corded headset for a part time job I was starting to work for.“ I didn’t want to spend very much money for one, as I wasn’t sure how good a fit the job would be with my schedule and was a little leery about actually getting paid (it is a work at home gig).“ So I decided to see what I could do on the cheap.“ We already had a pair of computer headphones with a built in microphone for use with the computers, and I figured I’d make them the center of my home brew setup.
I bought a cheap phone for $2 at the second hand store.“ Amazingly it worked great when I got it home, and I started putting phase two of my plan in place.
I bought a pair of headphone jacks for $2.99 at Radio Shack, and found an old computer network cable that I cut up to get some small cables for making the connections.
I found the cabling layout for the phone handset cord, and cracked the old phone open by removing thee screws:
(Click on the picture for a larger view -thanks to Pedro Rebello de Andrade for the original picture)
Tracing the cables back from the handset jack on the phone, I could see where the jack connected to the circuit board of the phone.“ I got lucky that my phone used the colors referenced above – you may have to use the numbered sequence of pins on the jack soldered to the circuit board.
I made two small holes in the case of the phone (using a kitchen knife, much to my wife’s chagrin) where there was empty space so I could close it up again with no problems, and screwed the two jacks into them.
Then, I soldered the Black and Yellow (#1 and #4) two one of the jacks and labeled it “Mic” and made it pink with a red Sharpie I had to match the color on the plug.“ Red and Green (#2 and #3) were connected to the other jack with a 470 Ohm resistor in-line.“ I used a 470 resistor as that’s all Radio Shack had in stock – I figured it was close enough and at $0.09 for five, I could afford to make a mistake. The jack was then labeled “Phones” and colored Green (also with a Sharpie) to match the color on the plug of the headphones.
The phone was put back together, and the headphones/mic were plugged onto the jack.“ I had sound in the headphones, and my test caller said my voice was coming through nice and clear.
My total cost: $5.98 – not bad, considering the cheapest phone at Wal Mart was $9.99, and it didn’t even have a handset jack at all being an all-in one phone.“ If you need a headset for this, WalMart has one for under $5, so your total outlay would be $7.96 if you can find an old/used phone for the same price.
You do have to be a comfortable with a soldering iron, but if you’ve got any kind of basic soldering skills, this should be a breeze for you.