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Who makes retractable antenna for laptop card?

Last response: in Wireless Networking
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July 4, 2004 6:52:44 PM

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

What manufacturers make a laptop PC-Card that has a retractable antenna,
which otherwise can be dangerous if you move the laptop with a protruding
antenna and forget to pop out the card. A friend once cracked his laptop's
motherboard after hitting a door with the antenna portion of his wireless
card.

If they exist:

Make?

Model?
Anonymous
a b D Laptop
a b F Wireless
July 4, 2004 6:52:45 PM

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

On Sun, 04 Jul 2004 14:52:44 GMT, "Pat" <hotpatpar@hotmail.com> wrote:

>What manufacturers make a laptop PC-Card that has a retractable antenna,
>which otherwise can be dangerous if you move the laptop with a protruding
>antenna and forget to pop out the card. A friend once cracked his laptop's
>motherboard after hitting a door with the antenna portion of his wireless
>card.

Well, they're available for Bluetooth:
http://www.psism.com/pcabt1.htm
but I couldn't find a similar 802.11 wireless card construction.

Many of the older Proxim PCMCIA (Symphony, Rangelan, HomeRF) wireless
devices had removeable antennas. For example:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3490...
However, those antennas tended to disappear, break off, or develop
intermittant connections. Not recommended.


--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558
Anonymous
a b D Laptop
a b F Wireless
July 4, 2004 8:28:25 PM

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

Pat wrote:

> What manufacturers make a laptop PC-Card that has a retractable antenna,
> which otherwise can be dangerous if you move the laptop with a protruding
> antenna and forget to pop out the card. A friend once cracked his laptop's
> motherboard after hitting a door with the antenna portion of his wireless
> card.
>
> If they exist:
>
> Make?
>
> Model?
>
>
>
3Com do some with the "X-Jack" antenna. I have the 11g version, and I'm
very pleased with it. I didn't want to have to remove the card when I
put then laptop in it's bag.

They're a bit pricey compared to linksys etc though.

http://www.3com.com/prod/en_UK_EMEA/detail.jsp?tab=feat...
Related resources
Anonymous
a b D Laptop
a b F Wireless
July 6, 2004 8:14:34 PM

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

"Pat" <hotpatpar@hotmail.com> wrote in message
news:0RUFc.15876$MT5.5868@nwrdny01.gnilink.net...
> What manufacturers make a laptop PC-Card that has a retractable antenna,
> which otherwise can be dangerous if you move the laptop with a protruding
> antenna and forget to pop out the card. A friend once cracked his laptop's
> motherboard after hitting a door with the antenna portion of his wireless
> card.
>
> If they exist:
>
> Make?
>
> Model?
>
>
>


Pat,

There are two 3Com products that use the patented X-Jack antenna that
retracts into the PC Card when not in use. The first is the a/b/g PC Card
($135 List)

http://www.3com.com/products/en_US/detail.jsp?tab=featu...

The second is the .11g card ($76 list)

http://www.3com.com/products/en_US/detail.jsp?tab=featu...

Grant
Anonymous
a b D Laptop
a b F Wireless
July 6, 2004 10:06:47 PM

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

"Grant Jones" <gjones@NOSPAM-utah-inter.net> wrote in message
news:KdAGc.2$9e1.403@news-west.eli.net...
<snip>
> There are two 3Com products that use the patented X-Jack antenna that
> retracts into the PC Card when not in use. The first is the a/b/g PC Card
> ($135 List)
>
>
http://www.3com.com/products/en_US/detail.jsp?tab=featu...
>
> The second is the .11g card ($76 list)
>
>
http://www.3com.com/products/en_US/detail.jsp?tab=featu...
>
> Grant

I had the 3Com 11a/b/g card (3CRPAG175) and had to return it because it was
causing lockups in my Dell Inspiron 8000. Strangely the lockups only
occurred at 11g speeds and not 11b (Win XP Pro) but was fine at any speed
under Win Me.

I also have the 3Com 11b card and have kept that as it works fine. Both have
the retractable antenna. However, I would have to say that the RF
performance is compromised by the retractable antenna design and I get much
better results with my Netgear WG511 that replaced the 3CRPAG175.
July 8, 2004 3:47:16 AM

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

"Tiny Tim" <_tim_dodd@hotmail.com> wrote in message
news:2l04h9F73k33U1@uni-berlin.de...
>
> I also have the 3Com 11b card and have kept that as it works fine. Both
have
> the retractable antenna. However, I would have to say that the RF
> performance is compromised by the retractable antenna design and I get
much
> better results with my Netgear WG511 that replaced the 3CRPAG175.
>
>

Retractable seems like a great idea. So far, I like the Netgear WG511T but
its drawback is a big fat antenna that protrudes.
Anonymous
a b D Laptop
a b F Wireless
July 15, 2004 10:50:27 AM

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

On Thu, 15 Jul 2004 08:11:47 GMT, John S <none@none.none> wrote:

>I have used a ton of the classic Orinocos but never have taken one apart
>so your picture in your other response was interesting. I thought they
>used the dual antenna diversity scheme too but maybe I am wrong.

Dunno. I only take apart the radios that do NOT work well, so I've
never bothered to disassemble an Orinoco radio. If there's a
diversity RF switch, it's on the bottom which is not in the photo. If
I need entertainment, I'll tear one apart.
http://www.geocities.com/lincomatic/orinocoant.html
However, looking at the horizontal antenna pattern, with it's pair of
symmetrical deep nulls, I would guess(tm) that the two PIFA are being
run through some kind of combiner. Difficult to tell.
http://www.proxim.com/support/all/orinoco/technotes/ant...

>I still
>do not understand the circuit though.

Which circuit? The WPC11 schematic is fairly simple if you totally
ignore the use of improper schematic symbols. My guess(tm) is that
it's simply a SPDT (or dual SPST) PIN diode switch. The real question
is what algorithm is used to switch antennas. My guess(tm) is that if
the S/N ratio drops below some level, it switches antennas in the hope
that reception on the other antenna will be better. I've seen some
access points, with diversity antenna systems, that use diversity only
on receive and always transmit into one antenna. That drove me nuts
for about a week trying to setup an access point with one antenna for
outdoors and the other for indoors. I could make one or the other
work, but not both. I'm not convinced that diversity actually works
well enough to justify the efforts.

>And I do not understand how the
>external antenna can be "paralleled" without screwing up the
>VSWR/Pattern etc.

If both antennas can see each other, then running the antennas through
a combiner (resistive, Wilkinson, active mixer, etc) will result in a
conglomerated pattern full of nulls, peaks, and problems. However, if
the antennas are sufficiently separated so that both antennas do not
simultaneous hear the same signals, then the pattern will be the same
as a single antenna. However pattern mangling is not the problem.
It's that two physically diverse antennas are most likely to pickup
additional noise sources without much improvement in signal reception.
The only way around that is to switch antennas as in the various
diversity schemes.

>You sound like an RF circuit design engineer too.

Sorta. I did that full time for about 15 years. These days, I do
computah repair/consulting and RF consulting. I try to keep up to
date on both, but it's rough. Most of the stuff I post in the various
newsgroups and mailing list involve no more than the fundamentals.

>I hated antenna
>design since the final result was hard to test without a chamber.

Antenna design is little better than magic. I've verified some of my
designs and was amazed at the discrepancies between theory and
reality. At 2.4GHz, a relatively small chamber will do the trick.

>And
>back when we used NEC simulator the input modeling was a hassle. Hope it
>is easier to use now.

Oh yes. Things are much easier these days. User hostile NEC2 and
NEC4 Fortran based calculation engines are now the back end
calculators with various user friendlish programs at the front end. I
still recall discussing antenna modeling with one of the luminaries of
NEC modeling at a meeting. He couldn't understand why anyone would
need a 3D visualization of the pattern or a near field pattern. That
was 10 years ago and much has changed since.
http://www.nec2.org
http://www.qsl.net/wb6tpu/swindex.html
http://www.gweep.ca/mailman/listinfo.cgi/nec-list
If you wanna play, I suggest the freeware 4NEC2 software or the EZNEC
demo. Here's some sample output for a 1lb coffee can:
http://www.LearnByDestroying.com/antennas/coffee2400/in...

These daze, everything is first modeled on the the computah. It's too
difficult to do cut-n-try design work. I was quite successful with
cut-n-try 30 years ago, but with todays high density circuits, the
very concept of a "breadboard" is dead issue. If it doesn't first
work on the computah, it probably won't work when it's built.


--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558
Anonymous
a b D Laptop
a b F Wireless
July 16, 2004 10:49:49 AM

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

In article <vtvcf0t8k1lun400h87jpennaktfi0njbd@4ax.com>,
jeffl@comix.santa-cruz.ca.us says...

Top Posted - Thanks - Nothing new to add.

> On Thu, 15 Jul 2004 08:11:47 GMT, John S <none@none.none> wrote:
>
> >I have used a ton of the classic Orinocos but never have taken one apart
> >so your picture in your other response was interesting. I thought they
> >used the dual antenna diversity scheme too but maybe I am wrong.
>
> Dunno. I only take apart the radios that do NOT work well, so I've
> never bothered to disassemble an Orinoco radio. If there's a
> diversity RF switch, it's on the bottom which is not in the photo. If
> I need entertainment, I'll tear one apart.
> http://www.geocities.com/lincomatic/orinocoant.html
> However, looking at the horizontal antenna pattern, with it's pair of
> symmetrical deep nulls, I would guess(tm) that the two PIFA are being
> run through some kind of combiner. Difficult to tell.
> http://www.proxim.com/support/all/orinoco/technotes/ant...
>
> >I still
> >do not understand the circuit though.
>
> Which circuit? The WPC11 schematic is fairly simple if you totally
> ignore the use of improper schematic symbols. My guess(tm) is that
> it's simply a SPDT (or dual SPST) PIN diode switch. The real question
> is what algorithm is used to switch antennas. My guess(tm) is that if
> the S/N ratio drops below some level, it switches antennas in the hope
> that reception on the other antenna will be better. I've seen some
> access points, with diversity antenna systems, that use diversity only
> on receive and always transmit into one antenna. That drove me nuts
> for about a week trying to setup an access point with one antenna for
> outdoors and the other for indoors. I could make one or the other
> work, but not both. I'm not convinced that diversity actually works
> well enough to justify the efforts.
>
> >And I do not understand how the
> >external antenna can be "paralleled" without screwing up the
> >VSWR/Pattern etc.
>
> If both antennas can see each other, then running the antennas through
> a combiner (resistive, Wilkinson, active mixer, etc) will result in a
> conglomerated pattern full of nulls, peaks, and problems. However, if
> the antennas are sufficiently separated so that both antennas do not
> simultaneous hear the same signals, then the pattern will be the same
> as a single antenna. However pattern mangling is not the problem.
> It's that two physically diverse antennas are most likely to pickup
> additional noise sources without much improvement in signal reception.
> The only way around that is to switch antennas as in the various
> diversity schemes.
>
> >You sound like an RF circuit design engineer too.
>
> Sorta. I did that full time for about 15 years. These days, I do
> computah repair/consulting and RF consulting. I try to keep up to
> date on both, but it's rough. Most of the stuff I post in the various
> newsgroups and mailing list involve no more than the fundamentals.
>
> >I hated antenna
> >design since the final result was hard to test without a chamber.
>
> Antenna design is little better than magic. I've verified some of my
> designs and was amazed at the discrepancies between theory and
> reality. At 2.4GHz, a relatively small chamber will do the trick.
>
> >And
> >back when we used NEC simulator the input modeling was a hassle. Hope it
> >is easier to use now.
>
> Oh yes. Things are much easier these days. User hostile NEC2 and
> NEC4 Fortran based calculation engines are now the back end
> calculators with various user friendlish programs at the front end. I
> still recall discussing antenna modeling with one of the luminaries of
> NEC modeling at a meeting. He couldn't understand why anyone would
> need a 3D visualization of the pattern or a near field pattern. That
> was 10 years ago and much has changed since.
> http://www.nec2.org
> http://www.qsl.net/wb6tpu/swindex.html
> http://www.gweep.ca/mailman/listinfo.cgi/nec-list
> If you wanna play, I suggest the freeware 4NEC2 software or the EZNEC
> demo. Here's some sample output for a 1lb coffee can:
> http://www.LearnByDestroying.com/antennas/coffee2400/in...
>
> These daze, everything is first modeled on the the computah. It's too
> difficult to do cut-n-try design work. I was quite successful with
> cut-n-try 30 years ago, but with todays high density circuits, the
> very concept of a "breadboard" is dead issue. If it doesn't first
> work on the computah, it probably won't work when it's built.
>
>
>
!