External antennae for notebooks and others...

Hi,

I have seen a lot of discussion about this, and have seen a number of
offerings, all of which seem to involve lots of "bodges" ... with pigtails,
and replacement connectors.... etc etc ...

Given that the radio signal appears to be the critical part, and the more
connectors / adapters you add the greater the signal loss, is it possible to
use a USB wifi "dongle" with a metal mesh reflector, and rely on the USB
cable to carry the digital signal ...

Would there be any snags to this approach?

What would be the maximum length of USB cable? And could a Powered USB Hub
increase this ?

Regards

John



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> Given that the radio signal appears to be the critical part, and the more
> connectors / adapters you add the greater the signal loss, is it possible to
> use a USB wifi "dongle" with a metal mesh reflector, and rely on the USB
> cable to carry the digital signal ...

You mean something like this?

http://www.nodomainname.co.uk/cantenna/IMG_0384s.jpg

http://www.nodomainname.co.uk/cantenna3/cantenna3.htm



> Would there be any snags to this approach?

Not really

> What would be the maximum length of USB cable? And could a Powered USB Hub
> increase this ?

USB cable length is 5m max, you can string 5 active cables together so
lets call that 25m.

David.

John Beeston wrote:
> Hi,
>
> I have seen a lot of discussion about this, and have seen a number of
> offerings, all of which seem to involve lots of "bodges" ... with
> pigtails, and replacement connectors.... etc etc ...
>
> Given that the radio signal appears to be the critical part, and the
> more connectors / adapters you add the greater the signal loss, is it
> possible to use a USB wifi "dongle" with a metal mesh reflector, and
> rely on the USB cable to carry the digital signal ...
>
> Would there be any snags to this approach?
>
> What would be the maximum length of USB cable? And could a Powered
> USB Hub increase this ?
>
> Regards
>
> John
>
would this be any good?

http://www.linksys.com/products/prod...id=36&prid=612




--
Mike E

"David Taylor" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ...
> > Given that the radio signal appears to be the critical part, and the
more
> > connectors / adapters you add the greater the signal loss, is it
possible to
> > use a USB wifi "dongle" with a metal mesh reflector, and rely on the USB
> > cable to carry the digital signal ...
>
> You mean something like this?
>
> http://www.nodomainname.co.uk/cantenna/IMG_0384s.jpg
>
> http://www.nodomainname.co.uk/cantenna3/cantenna3.htm
>
>
>
> > Would there be any snags to this approach?
>
> Not really
>

Very impressive, but I was thinking of something far simpler ... this
approach still has mentions of brass bits, solder, and pigtails...

But there again, perhaps I do not understand the full complexities...

I was thinking more of a small self contained USB device such as the
linksys WUSB12 or D-Link DWL122 being placed at the focus of a suitable
dish and connected back to the PC using a standard USB extension cable (or
cables)

For the reflector I had something like a SKY satellite dish in mind, as
these are cheap, and easy to install.

John




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John Beeston <(E-Mail Removed)> wrote:
> I was thinking more of a small self contained USB device such as the
> linksys WUSB12 or D-Link DWL122 being placed at the focus of a suitable
> dish and connected back to the PC using a standard USB extension cable (or
> cables)

> For the reflector I had something like a SKY satellite dish in mind, as
> these are cheap, and easy to install.

The mini-USB won't properly paint a satellite dish. It might work in a
small can, like the one on David's page.
I used a DWL-122 witha 9" pie plate pretty effectively. I'm going to mount
it in the bottom of a coffee can next.

You need two coffee cans soldered together and cut off to about 6 inches,
and then mount the USB mini about half inch from the bottom end.

http://www.turnpoint.net/wireless/cantennahowto.html provides the
calculator and ideas. I was going to put the miniUSB in there, although
some experimentation to find the right focus and orientation.



--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8-122.5

On Fri, 2 Jul 2004 12:01:29 +0100, "John Beeston"
<(E-Mail Removed)> wrote:

>Given that the radio signal appears to be the critical part, and the more
>connectors / adapters you add the greater the signal loss, is it possible to
>use a USB wifi "dongle" with a metal mesh reflector, and rely on the USB
>cable to carry the digital signal ...

http://www.freeantennas.com
http://www.freeantennas.com/projects/Ez-10/

The nice part is that it doesn't require an pigtails. A USB radio
should work as well. I'll leave it to your ingenuity to figure out
how to do it with a PCMCIA card in a laptop. (ribbon cable
extension?)

>Would there be any snags to this approach?

That depends on your construction abilities. There have been
aluminium foil and cardboard corner reflectors built, that I consider
to be marginal and unstable, but it can't be any worse than a
cardboard pringles can antenna.

>What would be the maximum length of USB cable? And could a Powered USB Hub
>increase this ?

16ft for USB.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

Clarence, I am interested in your pie plate ... how / where did you mount
the DWL-122?

John


<(E-Mail Removed)> wrote in message
news:cc40h9$ajh$(E-Mail Removed)...
>
> The mini-USB won't properly paint a satellite dish. It might work in a
> small can, like the one on David's page.
> I used a DWL-122 witha 9" pie plate pretty effectively. I'm going to
mount
> it in the bottom of a coffee can next.
>
> You need two coffee cans soldered together and cut off to about 6 inches,
> and then mount the USB mini about half inch from the bottom end.
>
> http://www.turnpoint.net/wireless/cantennahowto.html provides the
> calculator and ideas. I was going to put the miniUSB in there, although
> some experimentation to find the right focus and orientation.
>
>




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> Very impressive, but I was thinking of something far simpler ... this
> approach still has mentions of brass bits, solder, and pigtails...

Not in the first picture I linked you to. All that's going on there is
a the antenna from a Netgear USB NIC poked up into the cardboard tube
(foil lined).

> I was thinking more of a small self contained USB device such as the
> linksys WUSB12 or D-Link DWL122 being placed at the focus of a suitable
> dish and connected back to the PC using a standard USB extension cable (or
> cables)
> For the reflector I had something like a SKY satellite dish in mind, as
> these are cheap, and easy to install.

It has been done before but it's just as easy to stuff the antenna into
a can and use the can in the place of the LNB.

David.

> 16ft for USB.

or 5 active cables strung together.

Jeff Liebermann <(E-Mail Removed)> wrote:
> The nice part is that it doesn't require an pigtails. A USB radio
> should work as well. I'll leave it to your ingenuity to figure out
> how to do it with a PCMCIA card in a laptop. (ribbon cable
> extension?)

I used a reflector with an Orinoco PCMCIA card.
I was holding the reflector with one hand, and the laptop with the other,
so it wasn't very useful, but NetStumbler definitely showed the effects of
the reflector being in place.
"I'll leave it to your ingenuity to figure out how to do it" in some
worthwhile fashion ;-)

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8-122.5