internal wifi antenna

Archived from groups: alt.internet.wireless (More info?)

I just installed a mini PCI wifi (802.11b) card in my TP600X and also
installed a pair of internal antenna routed just below the keyboard.
The signal received is very weak (one bar). So I disconnected that
antenna pair and hook up a spare and route that one outside if the
laptop. Same weak signal. Looking at the antenna wire, it looked like a
very small coax cable, terminated at one end on a small coax type
connector (center pin and snap ring on the ground side. What bothers me
is the other end. both the center wire and ground is soldered to a thin
metal bracket. So how does this antenna work when resistance wise it is
a short ?
Thanks.
13 answers Last reply
More about internal wifi antenna
  1. Archived from groups: alt.internet.wireless (More info?)

    juliuslr@gmail.com wrote:
    > I just installed a mini PCI wifi (802.11b) card in my TP600X and also
    > installed a pair of internal antenna routed just below the keyboard.
    > The signal received is very weak (one bar). So I disconnected that
    > antenna pair and hook up a spare and route that one outside if the
    > laptop. Same weak signal. Looking at the antenna wire, it looked like a
    > very small coax cable, terminated at one end on a small coax type
    > connector (center pin and snap ring on the ground side. What bothers me
    > is the other end. both the center wire and ground is soldered to a thin
    > metal bracket. So how does this antenna work when resistance wise it is
    > a short ?

    It won't work if it's as you described. Would it be too painful to you
    to mention the brand/model of the wireless gear?
  2. Archived from groups: alt.internet.wireless (More info?)

    The mini PCI is a Toshiba PA3272U-1MPC, with marking that says Intel
    WM3B2100. The driver is from Toshiba website intwlan2100ssox.exe

    My AP is a D-Link, and worked fine using my 600E and PCMCIA wifi card.
  3. Archived from groups: alt.internet.wireless (More info?)

    On 14 Aug 2005 19:52:16 -0700, juliuslr@gmail.com wrote:

    >I just installed a mini PCI wifi (802.11b) card in my TP600X and also
    >installed a pair of internal antenna routed just below the keyboard.

    Ummm, most of the laptop internal antennas are routed up to the top or
    side of the display section. It won't work very well with the
    radiating part of the antenna down low, near the RFI sources, under
    the shielded keyboard, etc.

    >The signal received is very weak (one bar). So I disconnected that
    >antenna pair and hook up a spare and route that one outside if the
    >laptop. Same weak signal.

    Good thinking. That should have made and antenna work better. Did
    waveing the antenna around change the signal level? It's not the
    greatest way to tell if it's working, but if the RF is coming from the
    antenna, you should see a change.

    >Looking at the antenna wire, it looked like a
    >very small coax cable, terminated at one end on a small coax type
    >connector (center pin and snap ring on the ground side. What bothers me
    >is the other end. both the center wire and ground is soldered to a thin
    >metal bracket. So how does this antenna work when resistance wise it is
    >a short ?

    Oh, that's easy. Any antenna that's 1/2 wavelength long is an open
    circuit at the resonant frequency. That's about 6mm at 2.4Ghz. To
    get 50 ohms, the coax cable is connected to a "tap" that's about
    10-20% of the distance from the ground (shield) end of the antenna to
    the grounded end point. There are also "slot" antennas, that are a
    piece of sheet metal with a 1/2 wave slot and the coax connected
    across the slot. Some antennas are "J-poles" which are either 1/2 or
    5/8 wavelength long, with a 1/4 wave driven element. Everything is
    grounded. There are also ceramic substrate tuned line antennas, which
    shrink the wavelength dimensions down to miniature size similar to
    what's used inside some cellphones.

    Be careful with the u-FL connectors. They are very flimsy, do not
    tolerate any abuse, and will break at the slightest provocation. If
    your antenna assembly was not designed specifically for your
    unspecified MiniPCI card, there may be a connector problem, or you may
    have trashed the connector if you forced it. Did it go "click" when
    you attached the connectors? That's a good sign that it fits.

    Antenna for IBM laptop with some nifty references:
    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5230419854
    Looks like a J-pole antenna.

    Installing an internal antenna in an IBM A31 laptop:
    http://www.jordanautomations.com/tpa31-internal-wifi-upgrade.html

    Ceramic antennas:
    http://www.gigaant.com/

    Some good stuff on antenna basics and theory:
    http://www.gigaant.com/?id=246&lang=1&state=1
    (see links in the right window).




    --
    Jeff Liebermann jeffl@comix.santa-cruz.ca.us
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    AE6KS 831-336-2558
  4. Archived from groups: alt.internet.wireless (More info?)

    On 15 Aug 2005 05:01:23 -0700, juliuslr@gmail.com wrote:

    >The mini PCI is a Toshiba PA3272U-1MPC, with marking that says Intel
    >WM3B2100. The driver is from Toshiba website intwlan2100ssox.exe

    That an Intel 2100 card:
    http://support.intel.com/support/wireless/wlan/pro2100/
    It's fairly generic as 802.11b cards go. If the Toshiba drivers
    didn't work, try the Intel drivers.

    >My AP is a D-Link, and worked fine using my 600E and PCMCIA wifi card.

    That means your unspecified model[1] of DLink wireless router works
    with your IBM 600E laptop and unspecified[1] wi-fi card and is
    probably not the source of the problem.

    [1] Kindly disclose the make and manufacturer of *ALL* your hardware
    or answers to your questions will tend to be vague and general. It is
    also a good idea to mention your exact operating system as driver
    issues tend to related to the OS.

    --
    Jeff Liebermann jeffl@comix.santa-cruz.ca.us
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    AE6KS 831-336-2558
  5. Archived from groups: alt.internet.wireless (More info?)

    It's RF - lots of RF antennae look like a short... at RF frequencies they
    are not - back EMF and all that stuff... ;-)

    Guy


    <juliuslr@gmail.com> wrote in message
    news:1124074336.200946.269540@g14g2000cwa.googlegroups.com...
    >I just installed a mini PCI wifi (802.11b) card in my TP600X and also
    > installed a pair of internal antenna routed just below the keyboard.
    > The signal received is very weak (one bar). So I disconnected that
    > antenna pair and hook up a spare and route that one outside if the
    > laptop. Same weak signal. Looking at the antenna wire, it looked like a
    > very small coax cable, terminated at one end on a small coax type
    > connector (center pin and snap ring on the ground side. What bothers me
    > is the other end. both the center wire and ground is soldered to a thin
    > metal bracket. So how does this antenna work when resistance wise it is
    > a short ?
    > Thanks.
    >
  6. Archived from groups: alt.internet.wireless (More info?)

    Hey, it's not worth a pie..........
    Go get a card to pop in the slot.
    They work better anyway.
    I got the top of the range Toshiba & ended up doing that & never regretted
    it.


    "Rôgêr" <abuse@your.isp.com> wrote in message
    news:5sudnZ2dnZ1GsmaHnZ2dnZyFnd6dnZ2dRVn-yJ2dnZ0@pghconnect.com...
    > juliuslr@gmail.com wrote:
    >> I just installed a mini PCI wifi (802.11b) card in my TP600X and also
    >> installed a pair of internal antenna routed just below the keyboard.
    >> The signal received is very weak (one bar). So I disconnected that
    >> antenna pair and hook up a spare and route that one outside if the
    >> laptop. Same weak signal. Looking at the antenna wire, it looked like a
    >> very small coax cable, terminated at one end on a small coax type
    >> connector (center pin and snap ring on the ground side. What bothers me
    >> is the other end. both the center wire and ground is soldered to a thin
    >> metal bracket. So how does this antenna work when resistance wise it is
    >> a short ?
    >
    > It won't work if it's as you described. Would it be too painful to you to
    > mention the brand/model of the wireless gear?
  7. Archived from groups: alt.internet.wireless (More info?)

    > Oh, that's easy. Any antenna that's 1/2 wavelength long is an open
    > circuit at the resonant frequency. That's about 6mm at 2.4Ghz. To
    > get 50 ohms, the coax cable is connected to a "tap" that's about
    > 10-20% of the distance from the ground (shield) end of the antenna to
    > the grounded end point. There are also "slot" antennas, that are a

    etc etc which is why I like digital electronics, there are two states:-

    1) it works
    2) it doesn't

    :)

    David.
  8. Archived from groups: alt.internet.wireless (More info?)

    On Mon, 15 Aug 2005 16:39:10 GMT, David Taylor <djtaylor@bigfoot.com>
    wrote:

    >> Oh, that's easy. Any antenna that's 1/2 wavelength long is an open
    >> circuit at the resonant frequency. That's about 6mm at 2.4Ghz. To
    >> get 50 ohms, the coax cable is connected to a "tap" that's about
    >> 10-20% of the distance from the ground (shield) end of the antenna to
    >> the grounded end point. There are also "slot" antennas, that are a

    >etc etc which is why I like digital electronics, there are two states:-
    >1) it works
    >2) it doesn't

    Wrong. Race states, hazards, timing issues, glitches, and state
    dependent software bugs makes digital electronics mimic the real world
    of analog electronics. Given a sufficiently complex digital system,
    the symptoms of digital failure are almost identical to the equivalent
    analog contraption.

    I like RF because it's all magic. Nothing is consistent, predictable,
    or definitive. I can wave my magic wand and make things work one day.
    The next day, nothing I do will make it work. The basic problem with
    RF (and all electronics) is that you can't see the electrons moving
    around. We're basically blind and have to rely on artificial means
    (i.e. test equipment) to see what's happening. At best, it's a rather
    poor visulization of reality. Computer simulations help but they are
    at best science fiction. Anyway, it's fun being a magician. I get to
    wear the pointed hat with the stars and crescents, wave a magic wand,
    and mutter 4 letter magic phrases over the circuitry. I can also
    dispense truly amazing explanations of what was wrong, which takes
    care of my science fiction addiction. Frankly, methinks that digital
    is boring, where everything is easily predictable, and totally devoid
    of entertainment value and magic.


    --
    Jeff Liebermann jeffl@comix.santa-cruz.ca.us
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    AE6KS 831-336-2558
  9. Archived from groups: alt.internet.wireless (More info?)

    > Wrong. Race states, hazards, timing issues, glitches, and state

    yeah yeah, I think you missed the subtlety of my humour. :)

    > I like RF because it's all magic. Nothing is consistent, predictable,

    A friend of mine built a spectrum analyser, it looked more like meccano
    with bits of PCB and ground plane stuff all over the place. Don't know
    if it ever worked or how. :)

    David.
  10. Archived from groups: alt.internet.wireless (More info?)

    David Taylor wrote:

    > etc etc which is why I like digital electronics, there are two states:-
    >
    > 1) it works
    > 2) it doesn't

    ROTFLMAO!
  11. Archived from groups: alt.internet.wireless (More info?)

    juliuslr@gmail.com wrote:
    > I just installed a mini PCI wifi (802.11b) card in my TP600X and also
    > installed a pair of internal antenna routed just below the keyboard.

    Bad idea. On notebook PCs, the antennas are placed at the top right and
    left corners of the display part of the notebook, with antenna cables
    routed up through the hinges. Even before wireless was standard, many
    notebooks included the antenna and the wires on every one, but the
    TP600X is pretty ancient.
  12. Archived from groups: alt.internet.wireless (More info?)

    On Mon, 15 Aug 2005 22:08:33 GMT, David Taylor <djtaylor@bigfoot.com>
    wrote:

    >> Wrong. Race states, hazards, timing issues, glitches, and state
    >
    >yeah yeah, I think you missed the subtlety of my humour. :)

    That's the problem with digital people. Everything has to be on/off,
    one/zero, funny/not-funny. Us analog types have in between states
    such as half funny.

    >> I like RF because it's all magic. Nothing is consistent, predictable,
    >
    >A friend of mine built a spectrum analyser, it looked more like meccano
    >with bits of PCB and ground plane stuff all over the place. Don't know
    >if it ever worked or how. :)

    The uglier it is, the better it works. That's true for RF, antennas,
    and network wiring. I'm always suspicious of anything that is neat,
    organized, or properly labeled. Anything that nice looking can't
    possibly work right. That's also why "ship the breadboard", and "no
    user serviceable parts inside" are popular. If the spectrum analyzer
    is as ugly as you indicate, it probably works just fine.

    Incidentally, the problem with RF test equipment is that it always has
    to be better than the radios that it's testing. That's not easy when
    the major limitations of the components and design are approaching
    physical limits (i.e. noise floor). That's why test equipment tends
    to be rather complex, exotic, and ugly.


    --
    Jeff Liebermann jeffl@comix.santa-cruz.ca.us
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    AE6KS 831-336-2558
  13. Archived from groups: alt.internet.wireless (More info?)

    > That's the problem with digital people. Everything has to be on/off,
    > one/zero, funny/not-funny. Us analog types have in between states
    > such as half funny.

    On the contrary, we just use more bits to represent those states and as
    long as you're not worried about a little quantisation error, it's close
    enough. At the end of the day, men only need about 2 bits for emotions
    anyway, it's the full 1024 bits that get implemented in women.

    David.
Ask a new question

Read More

WiFi Wireless Networking Product