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.
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.
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.
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:
formatting link
like a J-pole antenna.
Installing an internal antenna in an IBM A31 laptop:
's fairly generic as 802.11b cards go. If the Toshiba drivers didn't work, try the Intel drivers.
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.
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.
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.
yeah yeah, I think you missed the subtlety of my humour. :)
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. :)
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.
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.
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.
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.
Jeff Liebermann wrote in news: snipped-for-privacy@4ax.com:
I wouldn't say RF is all magic, but can be unpredictable. I do a lot of RF work for narrow-band licensed frequenciew from 100 mhz to 1 ghz and I can tell you, nothing sucks more that to fully align a transeiver out of it's enclosure and then when it goes together, have massive front-end desense because the frequencies 1/4 wavelength is exactly the distance between the 2 mounting screws, or their's some kind of birdie at a certain frequency which causes heavy intermod.
But, by just looking at a schemtaic, it's much easier to decipher analog circuitry and understand it than digital, to me anyway.
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