Introduction: Portable Skype Phone V2

Picture of Portable Skype Phone V2

Heres an easy way to make your own cordless phone skype ready, Dont need to open your phone, and you can dial from it as well! All for about $5.

Props to Vitali Virulaine at for coming up with, and sam for inspiring me to show him up, I hope you get into the maxim party!!!

Step 1: Parts Needed

Picture of Parts Needed

-2 mini audio plugs 1/8" (buy cheap headphones and cut off the plugs)
-an RJ11 Plug (buy a cheap phone cord and cut off one end)
-2 100OHM resistors
-500OHM variable resistor
-2 3.3uF capacitors
-9V adapter, or USB plug, or use the one currently in your phone.

Step 2: Building

Picture of Building

At first I was a little skeptical whether this would work or not, but I was pleasantly surprised when it did.
Connect the parts according to the schematic.
-I connected the grounds together and both left and right of the stereo plug together, since its going to be mono anyway.
-For the phone line cord, you use the center 2 wires only
-I didnt use a variable resistor, I used a 470OHM and it was loud enough
-Im currently powering it with my power supply, but will likely wire it into the phone's power supply. you could also run the wires to a usb plug and power it from your computer.

Step 3: Finishing.

Picture of Finishing.

If you have the skills you can make this into a nice PCB like Vitali did....

Step 4: Calling

Picture of Calling

Once your adapter is all hooked up, make a call to echo123 and make sure your sound and mic are working.

If you want to be able to dial from your phone, you will need to download the skype pluggin below.

You will need to calibrate this software to recognize your dialing volumes, just follow the wizard.
To make a call, pick up the phone, dial the number 15551234567 and press #
Alternatively, you can dial from skype.

Enjoy the freedom of your cordless phone!
Ive included a video of me calling from the phone as proof that it works!


gomalopa (author)2009-12-21

There is some software like chat cord dialer for MAC or linux, im using Xlite under those systems.

Hextor (author)2009-02-09

I tried the new schematic and it didn't work, I didn't use a pot though so perhaps that why. I agree that it's not to specific about how to connect it.

naoakes416 (author)2008-01-24

I looked up that schematic on google and it said that this particular setup had echo problems... have you experienced that at all? also it shows a slightly different newerversion but it doesnt explain it very well... and i was just wondering what to do. Thank you.

ratgod (author)2007-06-06

If you get an incomming voice chat request, does it allow you to accept it with a button press?

grahamslawson (author)ratgod2007-12-02

nope. Its not connected like that

Squeeto (author)2006-09-22

Thanks for the info. I could sure use one of these and I know I have all the parts. Unfortunately the software doesn't run on Windows 2000. I have read that the earlier beta versions to 1.3 do work for 2000. Any chance you know where I can get it? Chat-Cord@DialerSK 2.1.0 Setup "Chat-Cord@DialerSK runs only on Windows XP or Windows ME"

sagefool1975 (author)2006-08-08

Hmm, so I have made the original and modified circuit and they both seem to work fine, my problem is that the input volume doesn't match the output volume. So if I call the skype test center, leave my message and hear it played back to me, it is incredibly faint. I've tried playing with the gain levels on my input but even maxed out it doesn't get a great signal. Any thoughts?

TABRadi0 (author)2006-07-24

I know that, But I'm really setting this up for my grandparents, that aren't computer literate. I personally built one of these last week with no problems, It works great for me but it will be alot of hassle for them.

sirstargazer (author)TABRadi02006-08-01

do you have the echo problem? I've tried both the old and new version of this and I still get a bad echo

tommiedeboy (author)TABRadi02006-08-01

hey there TABRadiO, i'm dealing with the same problem and i'd like to get this solved. there must be something. i had another program but don't seems to work with my phone. here's the link:

please leave me a note if you've found something

TABRadi0 (author)2006-07-24

The Chat chord software is expired. Is there any other offered software that will work with this particular hardware?

sirstargazer (author)TABRadi02006-07-24

you don't need the software for this to work. the software just lets you dail using the phone's numpad. that's it. you can still use your phoen to talk without the chat cord software.

conalcharles (author)2006-07-01

Where do the guys in the US get electronic components from ? Does RadioShack have it off the rack or do you use some online sites ?

radioshack didn't have the capacitors here so I had to get it from another electronics shop. look in the phone book, i'm sure there are many small electronic shops out there.

tyeo098 (author)2006-06-28

ohh... nvm i get it

tyeo098 (author)2006-06-28

Uhh... Stupit Qwestion here how do u hook it up to the phone and stuff? just email me at (too lazi to chek back)

adoqpweoriuqwer (author)2006-06-21

I'm confused about the phone jack part of the circuit. Which of the pins do I want to connect and what do I want to connect them to? Maybe a picture would help to show the direction the jack is facing? Thanks

sharath (author)2006-06-18

I faced the following problem. I think the circuit is fine. During the installation of the plugin, under phone keys tuning, there was no response even though i pressed the keys. Further if i press the numeric keys on the computer keyboard, the installer recognizes them. Also, the phone display, constantly shows "Line in use", when i connect the ckt. What may be the problem ?

sirstargazer (author)sharath2006-06-20

did you make sure that the circuit really is working? when you use the phone, can you hear music you're playing in winamp or something?

sharath (author)sirstargazer2006-06-20

When i make a call in skype ,by pressing the keys on computer keyboard, i can hear the ringing sound. When the other person recives the call, i cant hear anything. not even noise.

sirstargazer (author)2006-06-20

has anyone tried the new circuit? i'm trying it out but can't seem to get it to work.

macfreak4 (author)2006-06-12

you haven't done anything wrong, according to the author's site. there's a modified circuit that was posted on the original author's site on june 16 -- the mic in audio jack is now connected before the 500 ohm pot instead of after. this is supposedly to eliminate echo, though I have not yet tried it (i built the original circuit listed here)

sirstargazer (author)macfreak42006-06-16

sorry hehe i'm blind or something and can't find the modified circuit you speak of. do you think you could post the link to that modified circuit? :)

the one on is the same one used here

haha oh wait, scratch that, it IS at I just didn't notice the line that says "or MODIFIED version (12 june 2006) (should resolve echo problem)" part way down from the top.

macfreak4 (author)2006-06-12

although, I had to use a 600 ohm resistor instead of the pot to get decent volume output from my wired phone -- go figure :P

sirstargazer (author)2006-05-30

I was under the impression that left and right were tied together and the 2 ground wires from each earpiece is tied together, thus giving you two ends. that's the way I have it built right now. I couldn't find a variable resister so I just use a 10ohm one instead. I was using a 470 one but I could only hear, not speak into the phone. I accedentally switched in a 10 and now I can both hear and speak but the person that i'm talking to on the other end will hear an echo of their voice and they can also somehow hear the speaker out signal comming out of my computer. anyone know what i might have done wrong? I'm going to try and increase the 10 to something closer to 470. maybe 400 or something.

sagefool1975 (author)2006-05-30

So with the mini stero audio plugs, should I just tie the left and the right channel together? As it is I am using left for - and right for + which gives me the fun of being able to adjust the volume by sliding the balance control away from center on my computer - but probably isn't so hot on the components.

tenemag (author)2006-05-29

I'm in the process of building one right now... actually, I'm wondering... What is the purpose of having the pot resistor on there? volume control? also, when I cut the phono wire I had, it had 3 wires inside, a white wire, a red wire, and a silver uncoated wire... which wires do I hook up for mic/spk? thanks!

Irregular Shed (author)2006-05-23

@ Hungry_Myst:

Looking at the way that the circuit uses the two USB ports, it's so as to get a total of 10V instead of 5V for the circuit (which, with the battery, is 9V). I think you could use a single USB port for power if you were willing to build a circuit to up the 5V to 9V... but you might end up going over the 100mA limit that a USB port will give to a device. It's a bit of an ugly hack either way - I'd pull 12V from a spare Molex connector and fiddle with the pot to control the gain.

Last night, when I saw this, I thought of a really neat way to use this circuit - marry it up to one of these cheap USB audio adaptors...
...and hook it up to an internal USB header - taking the power from a spare Molex connector, as mentioned above - and wire up a standard phone jack to a blanking plate - maybe even one stolen from an old modem =)

That would be fab stuff.

matt (author)Irregular Shed2006-05-24

The mini soundcard things, marketted as 5.1 virtual sound they should work fine and YOU CAN USE LESS THAN 9V. mine works fine using 1 USB port, that 5V.... Ive ordered one of these adapters, and am going to trying a run power from it, and hookup the capictors and shit all together inside its case.......
should be custom.

matt (author)2006-05-23

You are pretty much amplifying sound signals, so you dont need to use the exact resistors/capictors recommend, you can get away with 2.2uF or 80OHM resistors, if you cannot hear the sound, or it cant hear you properly, then you need to replace the parts....... As for powering it, you can use a single USB, you may need a transformer, im currently investigating that....... as for using the phone's power, open you phone and try running power off its transformer, if you find the sound is too quiet or you dont get the distance your used to, you may need to upgrade its transformer to one that will pump out more AMPs

DataCrash (author)2006-05-23

Awesome Instructable!!! I went out and got the parts and built it today... my first PC board project box! it works like a charm.... I could only find 4.7uF capacitors, but they seemed to work... the person at the other end of the call (on a land line) tends to hear some echo and slight feedback, not horrible, but a bit annoying... is this due to the change in capacitors, or maybe just my computer and wireless setup? any idea's on refining this would be awesome.... 3 cheers for VoIP!!!

andreq (author)2006-05-22

Are the 3.3uF capacitor really necessary ? Ive built one with 10uF and I get a lot of trouble... for exemple : My friend can hear the sound that the computer is actualy playing (even with Mic input selected...) .. Ill try to find 3.3uF and see if it help...I'll aslo try a 470ohm resistor instead of a pot (of 4kohm...)

wifigod (author)2006-05-22

Where is the best place to get the capacitors from? I tried Radio Shack and Digikey w/o much luck. I've been wanting to do a project like this for some time now, I'm excited somebody has posted instructions on Instructables. :-)

Hungry_Myst (author)2006-05-21

Any tips for using power from the phone? I haven't looked into it mind you, but would it be any more difficult then adding a resistor? Or could I use USB without takeing up 2 USB ports as was shown on the original website?

mikesty (author)2006-05-21

Alright. IIRC the grynx chat cord writeup dealt with euro phones, so I wasn't sure if perhaps you were a euro. I did know that Canada pretty much has the same telecom system as the U.S. - guess I should be more investigative next time :) Thanks! On another note, I think I am actually going to built two of these. One will be a cordless phone for skype as I have planned, but today I also found a broken old cordless phone with what I believe is a fully functional base station - I figure I can use the speakerphone on it while I'm at my desk to make skype phone calls :) If not that I can just use it to chat on vent while I'm in the room :P

matt (author)2006-05-21

The software has a built in speed dial, you just have to add numbers/skype-id...... as far as I know its not open source. Obviously it works with american phones, Im in canada, and we have the same standard of phone. Cheers

sagefool1975 (author)2006-05-21

Is there some source to the Chat-Cord for use non windows users?

sam (author)2006-05-20

i think i just got hustled... i was writing up the same thing...

mikesty (author)2006-05-20

Oh, hm, does this work with phones in America too though?

mikesty (author)2006-05-20

Thank you so much. I was looking to build a chat-cord when it was on GRYNX a long time ago but me being a lazy bum, I never got around to it. This seems like a simple alternative AND you've included circuit diagrams so I practically have to do no thinking. Plus, now with SkypeOut being 100% free I'm good to go :) This is an odd question, but - any chance I can trick the thing into hitting up Speed Dial? That's why I like my nice Skype contacts list. I'm pretty sure it can't be done, but IDK.

About This Instructable




Bio: I liked designing and building things long before I became an engineer, now I get paid to do it!
More by matt:crack and reset an electronic safeThe Original Potato CannonPortable Skype Phone v2
Add instructable to: