RJ10 output from Cordless Phone's Handset Unit!

Discussion in 'General Electronics Chat' started by tgotwalt1158, Sep 19, 2011.

  1. tgotwalt1158

    Thread Starter Member

    Feb 28, 2011
    111
    18
    Dear friends!
    I was just wondering that could it be possible to take a RJ11 normal telephone jack connection output from wireless handset unit of a cordless mobile phone. If yes, is it straightforward or much modification would be required, or not possible at all. Any response shall be highly appreciated.
    Regards.
     
    Last edited: Sep 19, 2011
  2. Externet

    AAC Fanatic!

    Nov 29, 2005
    758
    57
    It is very simple. Straight connections.
    I believe it is called RJ22 instead, but besides that; the central pair is one direction, the outer pair is the opposite direction.

    If your mobile telephone has microphone in and earphone out connections, just route them to the corresponding pair of the RJ22 typically coiled cord for a 'standard' handset.
    Most of the cords conductors are not solderable, you should build an adapter from your mobile to a RJ22 jack.

    Did that many years ago, connected a standard telephone handset to a sound card to use the early days of telephony software, it was called Dialpad then.

    Some mobile units may work better with a 'standard' handset with magnetic microphone, some may prefer an electret type.
     
  3. tgotwalt1158

    Thread Starter Member

    Feb 28, 2011
    111
    18
    Hi Externet! Thanx. O.K. I checked it out its RJ11 not RJ10, but I think you did not get my question. You know the cordless phones, in which there are 2 units, one is base unit connected to the wall outlet of telephone exchange by an RJ11 connector and the other is wireless handset unit which you could take around wirelessly and could talk. They come with different ranges normally from 100 to 300 metres. I am talking about this wireless handset unit, it has a mouth piece and headphone to speak and listen respectively and there are no other connectors at all. My question, is there a way to open this handset and attach one RJ11 inside to the PCB of the unit and use it for other things, lets say to attach to a computer modem.
     
  4. colinb

    Active Member

    Jun 15, 2011
    351
    35
    Note that telephone handsets usually use a 4P4C plug (aka RJ22), but the connection to the phone network uses a larger 6P2C RJ11 (single line) or 6P4C RJ14 (two-line) plug.

    See registered jack on Wikipedia for lots of information on this confusing topic. Simply figuring out the precise terminology to use for these things is the first step!
     
  5. colinb

    Active Member

    Jun 15, 2011
    351
    35
    It could be done—you can probably find the physical space for an RJ11 jack, but if you want to connect to a computer modem or other device that expects a phone network line connection (that is what RJ11 is for), you will need some electrical interface. The microphone and speaker on the handset would be separate signals, and you need to interface both to the single RJ11 circuit.

    You would probably have an easier time making the handset function as a plug-in handset to a phone unit with the 4P4C plug/jack, where the speaker and microphone have separate circuits. There is still the voltage level question, since the audio signal voltage you tap into might not be right for the phone unit.

    Personally, it doesn't sound worth the effort to me since plain plug-in phone handsets are nearly free. But, if it interests you, go for it.
     
  6. Externet

    AAC Fanatic!

    Nov 29, 2005
    758
    57
    If what you want is a wireless remote telephone jack, you need what is called rural telephone.
    It will replicate the functionality of a home landline telco jack, as example, on your yacht miles offshore.
    Not many in the market lately, since the cellular expansion worldwide.

    But : http://alconphones.com/new/index.ph...7455d2d736a3=e79ad91950fb6ec297fdaee2efeb4bbf

    There is better ways to obtain data comunication to a computer. It is WLAN - wireless local area networking- which is not really restricted to nearby range; with the proper equipment many miles range is not difficult at all.

    This post is placed wirelessly that way. I have no telephone company service. WLAN from a miles away serving my computer at home in the middle of a national forest, no wires :

    ------> http://s588.photobucket.com/albums/ss323/Innernet/?action=view&current=HFuWave.jpg

    Edited : The range of this ex-satellite TV discarded antenna I put together above is supposed to be about 50 miles line-of-sight, the transceiver is 2 Watts, USB + CAT5 adapter to reach inside the house PC. Cost was minimal and works beautifully.
     
    Last edited: Sep 19, 2011
  7. tgotwalt1158

    Thread Starter Member

    Feb 28, 2011
    111
    18
    Hi gentlemen! thanks to you both! I know about WLAN and other LAN systems, like Power LAN etc but they are quite expensive and I don't need very high bandwidth too. Further, quite few used cordless mobile are lying around uselessly. I have telephone connection in my home and want to relay this to a nearby (within 300 metres) friend's location. Having said that all, the project in itself is very fascinating and I will enjoy to build. So, you are telling that the headphone and mike wires are needed to connect to the RJ11 connector, that is usual 1 metre extension cable with 2 RJ11 male connectors on both sides, I have to cut-off one connector and sold the wires to the phone and mike respectively and the other side intact RJ11 connector then could be plugged in to the computer modem. Actually, connectors type is not important at all. I could use any connector. What is important is to make correct connections so that finally it could work successfully. You have mentioned that there are some difficulties depending upon model to model, like separate mike and headphone connections, magnetic or electret mike, separate headphone/mike circuits and electrical interface etc. This is why it is challenging and hence interesting and in the end useful too. Anyway, Externet and Collinb, thank you again to both of you and I am attaching schematic of one handset unit, please throw some light where to solder wires of RJ11 in this particular circuit.You could point out by arrows by MS Paint program.
    Regards
     
  8. Externet

    AAC Fanatic!

    Nov 29, 2005
    758
    57
    No. A modem needs other signals, not only audio in and out.

    Needs to recognize DC presence on telco; needs to recognize ringing AC, needs to seize the line by placing ~200Ω across the line...
     
  9. tgotwalt1158

    Thread Starter Member

    Feb 28, 2011
    111
    18
    So, you mean its a deadlock and it cannot be done! But the question is, the cordless is having both the signals i.e. Tx & Rc, only we have to do to pick from suitable place on the pcb of the handset unit, carryout some signal conditioning if necessary depending upon particular model, and that's it. Any comments?
     
Loading...