| Author | Message | ||
     Ryan Somebody |
I thought it would be a good idea (albeit a little simple) to build a cordless telephone. But this is besides my point, I am trying to create a cordless phone that I can use with my laptop to dial in to the internet (I don't think this is illegal, I'm still paying for my ISP, as long as it complies with FCC regulations). Do you know of a cordless phone that features a phone jack in the headset? For me this is just a cheap alternative to 802.11b/g and I like dynamic IP addresses. So far I have *ahem* "deconstructed" a 2.4 ghz analog cordless phone and found the main parts. My plan is to wire a phone cord into the speaker/microphone setup. Here are a few questions: can a use a modular cord (2 wires) or should I use a normal cord (4 wires)? Also, the phone has two seperate systems: a speaker,and a microphone; since most modems dont require 4 wires, can I just use the 2 wires from the speaker and tie them into the phone cord? The two wires have 1.5 volts of current running through them. I'm afraid that there may be a one-way diode and I will only be able to recieve data ,if I hook it up in this manner, not transmit. All I need is a dialtone- I have no need for the keypad, volume, etc... There must be a good reason for this not to have been done before (or at least for me to never had heard about it). What voltage does a standard phone line run at? I know how to make a phone-to-phone system with a 9 volt battery... Once again, have you ever heard of a handset that features a phone jack? I was also experimenting with this idea: using the mini-jack output from the handset and wiring it to a phone cord. Would this work? For some reason I don't like this concept. Lastly, is there any way to boost the range of my phone? I was wondering if a coil/antenna like used in the radio projects would work, but wouldn't that mess with the frequency? Here is the equipment I am using: BellSouth 2.4 GHZ Analog Cordless Phone and Xircom 10/100 ethernet 56 kbps modem on a Gateway 2000 Pentium 266 w/ Windows 2000 Pro. Keep in mind I have essentially no budget but ample access to electronics. Thanks for the feedback, and keep up the good work with the site! P.S. - do you know of an easy way to convert my Bell bike pump (not foot pump, the tall version) into a vacuum pump? It has some kind of one way valve that I can't find! | ||
| Simon Quellen Field (Sfield) |
Most modern cordless phones have a jack for connecting a hands-free headset. This jack has a matching 3 conductor plug. A normal phone jack and plug have only two wires per telephone. The three wires in the hands-free jack and plug are microphone, earphone, and common. Converting this half-duplex system to full duplex may be as simple as connecting the microphone and earphone wires together. Of course an 802.11b is 196 times faster... Don't bother trying to convert the bicycle pump. See my section on making a vacuum pump from cheap PVC parts. Boosting the range of the phone is not legal, and would cause interference with neighboring phones. | ||
| Ryan Somebody |
I bought a 2.5 mm minijack headset for $3 at RadioShack. I cut and stripped the wire,and found the three wires you mentioned. Green, Red, and a third bare copper. What do you mean by common? Is it another word for ground? The green and red wires correspond with the two wires on the phone cord I am using. I'm a little confused now though, the red wire from the miniplug is giving off a negative charge and the green a positive. The current is 3 volts. The wires are hard to join, they are very small and fray easily. What are the charges coming out of a phonejack? What are the polarity of the two middle wires (red and green). I think I may have to hook them up in reverse. When you said to connect the microphone and earphone wires (green adn red)together you mean to the phone jack right? I don't connect the "common" wire? I was never good with electricity and please excuse my misunderstanding. Thanks alot. | ||
| Simon Quellen Field (Sfield) |
Two circuits can share a wire "in common". This is often connected to ground, in which case they are the same thing. The bare wire is most likely the common connection. Since I have no schematic for your phone, anything I say about it will be simply guesswork. What I suggest is to simply experiment with it. If the phone cord has a red and a green wire, connect the bare wire from the phone jack to one of them (red or green), and connect the other two phone jack wires to the other. Then see if you get a dial tone. If you don't, then I am out of suggestions, and some other reader will have to help out. | ||
| Anonymous |
sorry about my spelling i was trying to type quicly | ||
| Anonymous |
I though of that idea too what you have to is take apart the phone as you mentioned there are 4 wires what you have to is conect the wires from the speaker to the wires fromk the mic but make sure u use something to lower the power coming into the mic because the phone amplifies the singal coming from the mic then u conect the 2 wires you have (well acullay 4 joined join together) to a conector then inot ur laptop's modem. In fact there is a divice you can buy to save you all the troubl but it costs $300 you can buy a cheap cordless phone for $60 and everything else for about $10 and don't worry this IS legal well unless the place where you live has laws on using moblie phones or radio deices. anyway if a corless phone extends the range of a phone line legaly what so different about hocking it up with a laptop? and to your other qusestion a standard phone line (where i life as least) runs at 33v in standby mode and 80v when in use. | ||
| Anonymous |
Can anybody help ? I have bought a cordless phone with two hand sets PANASONIC MODEL : KX-TG2382 (IT HAS 2 HAND SETS MODEL: KX-TGA230B) . It is my wish to use these hand sets at a distance of a 1 mile from each other. I wonder if anybody knows of a manufacturer or a way to sort this issue out. Where could I order an antennae which would boost the signal between these 2 handsets. May I point out that one of the hand sets would be used near to the base ( 20 yards or so) Thanks for all info From sunny Rio de Janeiro | ||
| Anonymous |
I don't think u could exend the ran that far maybe 1 km though | ||
| Anonymous |
The quesion I would add is how do you convert the modular handset phone output (4-wires) to a 2.5mm (3-wires) config so you can use a common 2.5mm plug headset-w-mic on the phone. Dont bother lookin for an adapter to do this, there isn't one (plantronics, corp saw to this). | ||
| curious |
What is the story behind Plantronics? Anyone have any details? | ||
| Anonymous |
Also Curious... I'd like to know the political/legal stuff that makes this sort of information amazingly difficult to find. I mean, really, it is not beyond most basic knowledge of electronics - using a common conductor to serve as the ground for signals going in opposite directions. So, why is it tough to find the 'standard' for the 4-conductor wire/3-conductor jack found on most headset devices. I have also found that the 'standard' Motorola jack (2.5mm, 3-cond) used for their walkie-talkies is apparently wired differently than the Plantronics mobile/cordless headset varieties. I've been looking into knowing what to swap (and adding any additional signal-regulating electronics if need be... caps, diodes, resistors) in order to make this work with my cellular and cordless jacks. Looks like I'll be following the 'try it and see' path. | ||
| Jules Unregistered guest |
I have a cordless telephone Panasonic model : KT-TC910C-B. My volume set on the handset does not work . I can hardly listen even in its higher level. What should I change? Please email me Thanks. | ||
| Simon Quellen Field (sfield) New member Username: sfield Post Number: 51 Registered: 12-2004 |
Just buy a new phone. Seriously, the price of a new phone is less than your time is worth. | ||
| MadScientist (madscientist) New member Username: madscientist Post Number: 1 Registered: 4-2005 |
Not sure about the plantronics issue specifically, but (digging in the archives here) it seems to me, that using an audio isolation transformer (could be cannibalized from an old modem) could solve your connection problem. As Simon said, connecting the mic and speaker wires together may work, but it also could form a feedback loop, causing oscillation. If this is the case, the ground could be connected to the center tap of an appropriate transformer, with the mic and speaker lines connected on either side. I havent tried this, but in theory, it would invert the phase, cancelling out oscillations. Then the 'line' could be tapped from the other side of the transformer, in full duplex. Keep in mind, the impedances of the transformer would have to be right. Chances are, since the question was posted 4 months ago, you have either solved it or abandoned the project, but I post anyway. Good luck. | ||
| Nick Kropelnicki (Unregistered Guest) Unregistered guest Posted From: 207.200.116.71 |
Don't forget that most likely, the wires on a 2.5 mm are coated to prevent shortage, so strip the wire about 2 - 3 inches, and burn about an inch. it's simple and goes very fast, so watch it. once you burn the coating, and blow it out, it will leave the bare wire exposed. I say this because with the red and green coating (even common is coated), no matter how much you splice it, there will be none exposed, so be sure to burn the coating off |
