Using USB "stick" adapter inside a cantenna

Anyone else doing this? Using a USB "stick" type adapter, the one
piece USB adapter with a USB connection on one end? I am using the
D-link DWL-122.
http://www.d-link.com/products/?pid=175 It comes with a 5-foot USB
extension cable. I paid $31 for it. So connecting in a cantenna was
simply a matter of drilling a hole then using pliers to enlarge it
enough for the USB connector to go through it. I used a 1-lb coffee
can. The USB type A female connector seems to help keep it snug and
upright in the can. I then strung the USB extension cable out the
window and taped it to the back of a plastic porch chair. Adjusting
the chair and tape to get it angled correctly. I may need to do
something more permanent. Suggestions?

What I liked about it was no soldering or connectors to buy.

I now get a signal strength of 2 out of 5 bars. About what I got
before. But now the connection is reliable. And I am consistently
getting 1.2-1.3 Mbps downloads!

Network Stumbler quotes signal to noise difference of -10dBm.

Anyone else done anything similar?

If anyone else tries to do this, look carefully at the "stick" type
USB adapters. Some do not come with a USB extension cable. I guess
they are oriented for use on laptops. The USB extension cable can
cost $20 or more!

How can I measure the effectiveness of the setup other than what I
have already done?

You can contact me directly at:

bobalston9 AT aol D O T c o m

Bob Alston <(E-Mail Removed)> wrote:
> http://www.d-link.com/products/?pid=175 It comes with a 5-foot USB
> extension cable. I paid $31 for it. So connecting in a cantenna was
> simply a matter of drilling a hole then using pliers to enlarge it
> enough for the USB connector to go through it. I used a 1-lb coffee

Tell me more. I have a DWL-122. I have a coffee can.
Did you drill in the bottom, or the side of the can? Where exactly? How
did you decide where to put the mini-USB? How is it oriented inside the
can? Have you tried different positioning and orientation within the can?

Can you put up a photo?

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

On Thu, 8 Jul 2004 21:46:15 +0000 (UTC), (E-Mail Removed)
wrote:

> Bob Alston <(E-Mail Removed)> wrote:
>> http://www.d-link.com/products/?pid=175 It comes with a 5-foot USB
>> extension cable. I paid $31 for it. So connecting in a cantenna was
>> simply a matter of drilling a hole then using pliers to enlarge it
>> enough for the USB connector to go through it. I used a 1-lb coffee
>
> Tell me more. I have a DWL-122. I have a coffee can.
> Did you drill in the bottom, or the side of the can? Where exactly? How
> did you decide where to put the mini-USB? How is it oriented inside the
> can? Have you tried different positioning and orientation within the can?
>
> Can you put up a photo?
>

<aol> me too! </aol>

If Bob wants to play, he might want to cut a slit in the wall of the can
instead of a hole, so he can slide the stick forward and backward to
determine the best position with respect to the back of the can.

I still like the idea of putting the stick in the back of a car headlight
assembly. <g>

--
Barry

(E-Mail Removed) wrote in message news:<cckfb7$g7$(E-Mail Removed)>...
> Bob Alston <(E-Mail Removed)> wrote:
> > http://www.d-link.com/products/?pid=175 It comes with a 5-foot USB
> > extension cable. I paid $31 for it. So connecting in a cantenna was
> > simply a matter of drilling a hole then using pliers to enlarge it
> > enough for the USB connector to go through it. I used a 1-lb coffee
>
> Tell me more. I have a DWL-122. I have a coffee can.
> Did you drill in the bottom, or the side of the can? Where exactly? How
> did you decide where to put the mini-USB? How is it oriented inside the
> can? Have you tried different positioning and orientation within the can?
>
> Can you put up a photo?
>
> ---
> Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8-122.5

A little more info can be found on this posting on my web site:

http://members.cox.net/tulsaalstons/...0Reception.htm

The hole is in the side of the can, at a precise distance from the can
bottom. The flat part of the DWL-122 faces the open end of the can.

Have not tried different positioning as I found the initial one
provided excellent results.

Sorry no pictures available right now.

Bob
Bob

> On Thu, 8 Jul 2004 21:46:15 +0000 (UTC), (E-Mail Removed)
> wrote:
>
> > Bob Alston <(E-Mail Removed)> wrote:
> >> http://www.d-link.com/products/?pid=175 It comes with a 5-foot USB
> >> extension cable. I paid $31 for it. So connecting in a cantenna was
> >> simply a matter of drilling a hole then using pliers to enlarge it
> >> enough for the USB connector to go through it. I used a 1-lb coffee
> >
> > Tell me more. I have a DWL-122. I have a coffee can.
> > Did you drill in the bottom, or the side of the can? Where exactly?
How
> > did you decide where to put the mini-USB? How is it oriented inside the
> > can? Have you tried different positioning and orientation within the
can?
> >
> > Can you put up a photo?
> >
>
> <aol> me too! </aol>
>
> If Bob wants to play, he might want to cut a slit in the wall of the can
> instead of a hole, so he can slide the stick forward and backward to
> determine the best position with respect to the back of the can.
>
> I still like the idea of putting the stick in the back of a car headlight
> assembly. <g>
>
> --
> Barry

Thanks for the suggestions but I do not feel I really need to play with the
placement of the stick. I positioned it based on calculations I found at
http://www.turnpoint.net/wireless/cantennahowto.html

Also, I would expect that the car headlight assembly costs a bit more than
an empty coffee can. However YMMV and IMO ect. There are clearly LOTS of
innovative ways to build "cantennas".

Bob


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Bob Alston <(E-Mail Removed)> wrote:

> http://members.cox.net/tulsaalstons/...0Reception.htm

http://makeashorterlink.com/?Q105513C8 goes to that same place.

> The hole is in the side of the can, at a precise distance from the can
> bottom. The flat part of the DWL-122 faces the open end of the can.

The precise distance is the same as for a bare probe?

I assume that a view into the open end of the can looks like a
keyhole, or the same as a standard cantenna "probe" but thicker.

Did you try reversing the mini-USB? I'm not sure if the can acts as a
waveguide, funnelling the RF to the antenna, or a reflector, where you want
the face of the mini-USB pointing toward the closed end.

How far is the mini-USB sticking up into the can? I presume that the
ceramic patch antenna is very near the top. I might expect to try to
center that in the can, although a normal probe is offset all the way to
one side of the can.

> Have not tried different positioning as I found the initial one
> provided excellent results.

Don't mess with success?

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

> The precise distance is the same as for a bare probe?
>

I believe it is not much different, perhaps by the width of one edge of
the antenna covering, which, when the flat surface is facing the open end of
the can, is not much. Also since the stick is centered in the hole at the
"precise" location, I can ass-ume that the antenna inside the stick is also.


> I assume that a view into the open end of the can looks like a
> keyhole, or the same as a standard cantenna "probe" but thicker.

Yup
>
> Did you try reversing the mini-USB? I'm not sure if the can acts as a
> waveguide, funnelling the RF to the antenna, or a reflector, where you
want
> the face of the mini-USB pointing toward the closed end.

No. As I understand it, the can acts as a waveguide.

>
> How far is the mini-USB sticking up into the can? I presume that the
> ceramic patch antenna is very near the top. I might expect to try to
> center that in the can, although a normal probe is offset all the way to
> one side of the can.

The mini-USB stick (or dongle) sticks up fully into the can. I pulled
the USB connector down thru the can hold until it stopped at the beginning
of the antenna cover.

>
> > Have not tried different positioning as I found the initial one
> > provided excellent results.
>
> Don't mess with success?

Yup.

But would like to find out more how to measure the results. I have
Network Stumbler and see about -10 dB difference between noise and signal.
Also Win XP reports 2 out of 5 bars. Need to be able to monitor packet
loss/resends.
Speed tests consistently show 1.2 Mbps. Which is slightly less than 1.3
Mbps I get from a PC located close to the antenna.

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


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On Fri, 9 Jul 2004 15:39:34 +0000 (UTC), (E-Mail Removed)
wrote:

>Did you try reversing the mini-USB? I'm not sure if the can acts as a
>waveguide, funnelling the RF to the antenna, or a reflector, where you want
>the face of the mini-USB pointing toward the closed end.

It acts a both a waveguide and a reflector. The USB antenna is
approximately 1/4 wavelength from the bottom of the can.

>How far is the mini-USB sticking up into the can? I presume that the
>ceramic patch antenna is very near the top. I might expect to try to
>center that in the can, although a normal probe is offset all the way to
>one side of the can.

Well, I lied. It's not a ceramic patch antenna like in the older
Linksys WUSB11 radios. It's a chunk of high permittivity/permeability
(polysulfone??) circuit board with an etched gold plated antenna.
See:
http://www.LearnByDestroying.com/pic...122/index.html
The antenna is on the top of the USB dongle (the side with the
flashing lights) and at the very end of the board. That means the
bulk of the RF comes out upward from the device. Looks like it was
made in house as it has no manufacturers stamp on the antenna.

It looks like it would be very easy to unsolder this antenna and
attach a pigtail. Just don't tell the FCC that I suggested this.

The FCC ID is KA22002090025-1
Internal Photos:
https://gullfoss2.fcc.gov/prod/oet/f...ive_or_pdf=pdf
Test report:
https://gullfoss2.fcc.gov/prod/oet/f...ive_or_pdf=pdf
From the bottom of the test report:
"4.7.2 ANTENNA CONNECTED CONSTRUCTION
The antenna used in this product is Printed-F Antenna without antenna
connector. And the maximum Gain of this antenna is only –4.56dBi."

Also, If you want (and if I cand find the time), I'll fire up 4NEC2
and conjur an antenna model of the MJB coffee can.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
# (E-Mail Removed)
# 831.421.6491 digital_pager (E-Mail Removed) AE6KS

I wonder then if I constructed my tin cantenna incorrectly. I wrongly
asssssuummed that the antenna was the length of the dongel. Since it is on
the top, perhaps I should lay down the dongle with the top located 1/4
wavelength from the end of the can.

What do you think?



--
Bob Alston

"Jeff Liebermann" <(E-Mail Removed)> wrote in message
news(E-Mail Removed)...
> On Fri, 9 Jul 2004 15:39:34 +0000 (UTC), (E-Mail Removed)
> wrote:
>
> >Did you try reversing the mini-USB? I'm not sure if the can acts as a
> >waveguide, funnelling the RF to the antenna, or a reflector, where you
want
> >the face of the mini-USB pointing toward the closed end.
>
> It acts a both a waveguide and a reflector. The USB antenna is
> approximately 1/4 wavelength from the bottom of the can.
>
> >How far is the mini-USB sticking up into the can? I presume that the
> >ceramic patch antenna is very near the top. I might expect to try to
> >center that in the can, although a normal probe is offset all the way to
> >one side of the can.
>
> Well, I lied. It's not a ceramic patch antenna like in the older
> Linksys WUSB11 radios. It's a chunk of high permittivity/permeability
> (polysulfone??) circuit board with an etched gold plated antenna.
> See:
> http://www.LearnByDestroying.com/pic...122/index.html
> The antenna is on the top of the USB dongle (the side with the
> flashing lights) and at the very end of the board. That means the
> bulk of the RF comes out upward from the device. Looks like it was
> made in house as it has no manufacturers stamp on the antenna.
>
> It looks like it would be very easy to unsolder this antenna and
> attach a pigtail. Just don't tell the FCC that I suggested this.
>
> The FCC ID is KA22002090025-1
> Internal Photos:
>
https://gullfoss2.fcc.gov/prod/oet/f...ive_or_pdf=pdf
> Test report:
>
https://gullfoss2.fcc.gov/prod/oet/f...ive_or_pdf=pdf
> From the bottom of the test report:
> "4.7.2 ANTENNA CONNECTED CONSTRUCTION
> The antenna used in this product is Printed-F Antenna without antenna
> connector. And the maximum Gain of this antenna is only -4.56dBi."
>
> Also, If you want (and if I cand find the time), I'll fire up 4NEC2
> and conjur an antenna model of the MJB coffee can.
>
>
> --
> # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
> # 831.336.2558 voice http://www.LearnByDestroying.com
> # (E-Mail Removed)
> # 831.421.6491 digital_pager (E-Mail Removed) AE6KS

I wonder then if I constructed my tin cantenna incorrectly. I wrongly
asssssuummed that the antenna was the length of the dongel. Since it is on
the top, perhaps I should lay down the dongle with the top located 1/4
wavelength from the end of the can.

What do you think?



--
Bob Alston



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On Fri, 9 Jul 2004 21:22:23 -0500, "Bob Alston" <bobalston AT aol
DOT com> wrote:

>I wonder then if I constructed my tin cantenna incorrectly. I wrongly
>asssssuummed that the antenna was the length of the dongel.

Assumption is the mother of all screwups.

>Since it is on
>the top, perhaps I should lay down the dongle with the top located 1/4
>wavelength from the end of the can.

Yep. That's the way it should be done.

>What do you think?

I think I need a vacation. I just trashed 3 hours tinkering with
4NEC2 antenna modeling software trying to model the coffee can. Let's
just say I have a bit more reading to do. Every time I try to
optimize the design, the coffee can just evaporates leaving only the
feed wire. This is not that way it's suppose to work.

So, I decided that someone must have done an NEC2 model of the can by
now. Googlexcavating, I found:
http://www.nec2.org/wlan.htm (near the bottom of page)
which had a ready to run, nec2 deck for a 100mm dia, 300mm long coffee
can feed. A bit of cut-n-paste resulted in the following pictures:
http://www.LearnByDestroying.com/pic...as/coffee2400/
Note that the feed wire is NOT a simple piece of wire, but a conical
assembly that offers a better match and better bandwidth.

I'm not sure where the optimum location for the USB dongle should be
in the can. My guess(tm) is that dead center, with the flat top of
the dongle (LED lights) facing forward.

However, that's not the way I would do it. The little antenna in the
dongle is inefficient (-4dBi gain) as compared to a simple dipole (or
monopole). I would be tempted to unsolder the antenna, and solder a
1/4wave monopole (or conical feed) to the former "tap" pad on the
board. The metal shield on the back of the board goes flat onto the
can and the monopole (or conical feed) goes through a hole in the side
of the can.

Another way is to build a patch, panel, or biquad antenna assembly
without the coax connector and just attach the USB radio to the back
of the panel, possibly with a very short piece of semi-rigid coax
cable.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
# (E-Mail Removed)
# 831.421.6491 digital_pager (E-Mail Removed) AE6KS