Connect with us

cellphone question

Discussion in 'Electronic Repair' started by Mike Muderick, Mar 17, 2006.

Scroll to continue with content
  1. If I leave my cell phone near my computer speakers I will hear occasional
    buzzing, clicking, etc. Before the phone begins to ring, I hear a
    dah..dah.daahhhhh. I know this is RF interference being picked up by the
    amplifier in the speaker. If one were to record this sound with a
    microphone at 11 or 22Khz, would it be possible to obtain any information
    (usable signal) from the recorded audio?
  2. Arfa Daily

    Arfa Daily Guest

    If you could then clean up the audio into a reasonable digital waveform, in
    the right format, and somehow then get it into a cellphone provider's
    software package, then I guess that you could, but I'm not sure that it
    would tell you anything useful. AFAIK, it's just a response from the phone,
    to the question
    " OI !! Are you still there ? Yes ? OK, let's set up a channel 'cause I'm
    about to ring you " or something along those lines, sent by the last cell
    that the phone had become registered on. Perhaps others on here know a lot
    more about it, but I think that's something like I remember reading it.

    Of course, what you're hearing may not be a data stream as such, at all. It
    may just be as a result of the phone's RF output frequency hopping about all
    over the place on some kind of spread spectrum scheme. Again, others here
    might be able to give a better answer on that.

Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day