any comments? any ideas?

I have setup a 802.11b wireless bridge between two buildings - use the first
generation Linksys WAP11 access points (the ones with the USB port).

- I used the hack and boosted the signal to 100% on each.
- The one unit is sitting in a basement window. The antenna's were replaced
with the radio shack 6db "duck" ones.
- The other unit is sitting below a window on a shelf, and I put a single
Hawking "high gain 6db" on it ...because it had a 2 ft cable - allowing me
to put it antenna on the sill.
- The two have clear line of site and are about 75' apart

Everything worked great for 2 years. Now the interesting part......

The one building had the windows replaced with new Andersen windows. That's
the window with the 10" high Hawking H-AI6SIP antenna
(http://www.amazon.com/exec/obidos/AS...160163-9816714)
.. The bridge now would no longer work. When the window was open - it
worked. When the window was closed, it would not. FYI - the original
window was a standard wood frame, single pane of glass, not metal or
plastic - all wood window.

I was going to look at getting an outside antenna and run a wire into the
house, etc .... but I had a spare Belkin F5D6900 antenna
(http://www.amazon.com/exec/obidos/tg...&s=electronics)
that is supposed to be used with a PCI desktop card. It is much shorter -
about 3 inches high and just clears the bottom part of the window frame.
The Belkin antenna is not a "high gain" antenna.

Once I swapped the Hawking with the Belkin - the connection re-established
and all is well - when the window is open and closed.

Anyone have any ideas on why it ..

1) the Andersen window blocked the signal, and

2) why the Belkin antenna worked when the Hawking would not?

--

<riggor9999>
| I have setup a 802.11b wireless bridge between two buildings - use the
first
| generation Linksys WAP11 access points (the ones with the USB port).
|
| - I used the hack and boosted the signal to 100% on each.
| - The one unit is sitting in a basement window. The antenna's were
replaced
| with the radio shack 6db "duck" ones.
| - The other unit is sitting below a window on a shelf, and I put a single
| Hawking "high gain 6db" on it ...because it had a 2 ft cable - allowing me
| to put it antenna on the sill.
| - The two have clear line of site and are about 75' apart
|
| Everything worked great for 2 years. Now the interesting part......
|
| The one building had the windows replaced with new Andersen windows.
That's
| the window with the 10" high Hawking H-AI6SIP antenna
|
(http://www.amazon.com/exec/obidos/AS...elt_l1/104-916
0163-9816714)
| . The bridge now would no longer work. When the window was open - it
| worked. When the window was closed, it would not. FYI - the original
| window was a standard wood frame, single pane of glass, not metal or
| plastic - all wood window.
|
| I was going to look at getting an outside antenna and run a wire into the
| house, etc .... but I had a spare Belkin F5D6900 antenna
|
(http://www.amazon.com/exec/obidos/tg...pd_sxp_f/104-9
160163-9816714?v=glance&s=electronics)
| that is supposed to be used with a PCI desktop card. It is much shorter -
| about 3 inches high and just clears the bottom part of the window frame.
| The Belkin antenna is not a "high gain" antenna.
|
| Once I swapped the Hawking with the Belkin - the connection re-established
| and all is well - when the window is open and closed.
|
| Anyone have any ideas on why it ..
|
| 1) the Andersen window blocked the signal, and
|
| 2) why the Belkin antenna worked when the Hawking would not?
|
|

1 the Andersen windows likely have a metalized thermal insulation.

2 the link budget on the hawking was lower the belkin and in the original
case made no difference (like the military definition of rape 'penetration
however slight is sufficient to complete the act"

On Sat, 16 Jul 2005 15:16:22 -0400, <riggor9999> wrote:

>I have setup a 802.11b wireless bridge between two buildings - use the first
>generation Linksys WAP11 access points (the ones with the USB port).

I have about 5 of those pieces of junk in a pile somewhere. They were
the first cheap transparent bridge radios in their day. After about 5
major revisions of the Atmel firmware, and the pieces of junk were
still locking up all the time, I gave up on them. I'm glad you got
them working.

Incidentally 1.0 and 1.1 had the USB port. 2.2, 2.6 and 2.8 did not
have the USB port. 1.0 was junk. 1.1 is improved junk that didn't
lockup as much. 2.2 and above are fine.

>- I used the hack and boosted the signal to 100% on each.

Good for you. I wonder if the FCC offers a reward for turning in
spectrum polluters? The problem is that cranking up the power beyond
the rated and tested levels causes the tx amplifier to spray garbage
beyond the typical 26MHz of occupied bandwidth for 802.11b. It also
creates amplitude (envelope) distortion which severely affects the
ability of the receiver to extract the data. You may crank out more
RF, but how much of it is in the receiver bandpass, and how much of it
can be used by the receiver is questionable.

As I recall, the WAP11 running DWL-900AP+ firmware, which is what I
guess you were doing, doesn't really increase the tx power enough to
cause a problem. However, if you find that you are running a system
sufficiently marginal that you need the extra power, methinks you
should look instead for a better antenna pair or better line of sight,
as such a marginal system is sure to eventually fail when something
changes.

>- The one unit is sitting in a basement window. The antenna's were replaced
>with the radio shack 6db "duck" ones.
>- The other unit is sitting below a window on a shelf, and I put a single
>Hawking "high gain 6db" on it ...because it had a 2 ft cable - allowing me
>to put it antenna on the sill.
>- The two have clear line of site and are about 75' apart

Are the at the same vertical elevation? If not, the omni antennas
should be parallel to each other for best performance. I would NOT
use omni antennas for such a point to point link. The WAP11's have
RP-TNC connectors and decent antennas are easy to build or buy. My
version of the common biquad in an outdoor box:
http://802.11junk.com/jeffl/pics/antennas/biquad2/

>Everything worked great for 2 years. Now the interesting part......
>
>The one building had the windows replaced with new Andersen windows. That's
>the window with the 10" high Hawking H-AI6SIP antenna
>(http://www.amazon.com/exec/obidos/AS...160163-9816714)

6dBi of antenna gain (maybe) with about 3ft of RG-316 for a loss of
1dB. Net gain is about 5dBi if you ignore connector and adapter
losses.

>. The bridge now would no longer work. When the window was open - it
>worked. When the window was closed, it would not. FYI - the original
>window was a standard wood frame, single pane of glass, not metal or
>plastic - all wood window.

It's difficult to tell without seeing the window. Many windows have a
sputtered aluminium coating to improve insulation qualities. Most
double pane windows do this. Blocks RF quite nicely. The new science
building at the local university (UCSC) has windows almost impervious
to RF which is causing problems using cell phones inside the building.

Another possiblity is a vertical difference in elevation as I
previously asked. The Hawking antenna tend to radiate most of its RF
near the base of the antenna. If the base was partially obstructed by
a metal frame window, then you will have some signal loss. Similarly,
the wooden frame window will pass more RF throught the wooden frame.

>I was going to look at getting an outside antenna and run a wire into the
>house, etc .... but I had a spare Belkin F5D6900 antenna
>(http://www.amazon.com/exec/obidos/tg...&s=electronics)
>that is supposed to be used with a PCI desktop card. It is much shorter -
>about 3 inches high and just clears the bottom part of the window frame.
>The Belkin antenna is not a "high gain" antenna.

I'm not sure I would even call it an antenna. Zero specifications on
the Belkin web pile. No clue as to the gain, length of cable, or type
of cable. My guess is a simple vertical coaxial antenna with a
theoretical gain of 2dBi, perhaps 3ft of cheap non-PTFE coax for a
loss of about 1.6dB, with a net gain of 0.4dBi. Don't bother.

What part of the antenna "just clears" the window frame? This is
critical as the entire antenna, including parts of the base, must
clear the window frame. If not, and you get too close to the metal
frame, you end up detuneing the antenna, creating VSWR, havoc, etc.

>Once I swapped the Hawking with the Belkin - the connection re-established
>and all is well - when the window is open and closed.

Well, I'm suprised as I would think the Hawking antenna would have
more gain than the Belkin. Elevation difference (tilt angle) again?

>Anyone have any ideas on why it ..
>1) the Andersen window blocked the signal, and

Metal frame instead of wood. Aluminium sputtered coating.

>2) why the Belkin antenna worked when the Hawking would not?

Dunno. Many such antennas have a tendency to place much of their RF
in the upwards direction. Uptilt is more of a problem with high gain
omni antennas, where you could easily send the signal over everyone's
heads or to the sky instead of the ground. However, on all counts, I
would have expected the Belkin antenna to be far worse than the
Hawking. Assuming everything is working properly, I'm guessing that
you have a really marginal link, where any small changes in position
or antenna location will cause difficult to predict changes in antenna
patterns. For example, reflections from the window frames or other
objects in the path. Is your system *VERY* sensitive to exact antenna
location?

However, you're doing this all wrong. Omni antennas are not a good
idea for a point to point link. Use directional gain antennas. Even
two coffee can antennas would be a major improvement. Coffee can
antennas are about 8dBi gain. Single panel antennas are about the
same. Biquad's can go up to 10dBi gain. Assuming your existing pair
of omnis each has a gain of 2dBi, a pair of biquads will yield a 16dBi
increase in fade margin, which is a *HUGE* improvement. Maybe then
you might turn down the RF power to normal levels and not trash the
neighborhood.


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

To answer your questions / address your concerns:

- I am using several of the Linksys WAP11 ver 1.1 without any problems at
all. I have been for years.

- I realize this is not a perfect setup / not optimal....but this is a
light use / occasional use link. Not a commercial use / link. I set it up
with what I had on hand - trying not to spend any extra time or money. Just
put the units behind some windows / curtains, and tried not to be and eye
sore.

- The link is not and has not been sensitive to antenna placement at all.
The antenna sits on a window sill and is moved every so often for various
reasons.

- I used the Atmel utilities to increase the power
(http://www.seattlewireless.net/index.cgi/Wap11Hack) - not the D-Link
firmware hack.

- I have NEVER had a problem with this bridge in 2 years. All this started
when the windows were replaced - the antenna and signal strength and
connection was ALWAYS rock solid before the windows were changed.

- I got the all omni antennas for free - and since they are on 75 feet with
clear line of site - I don't think it matters for this short distance ...
omni versus directional.

- The window I am talking about with the Hawking / Belkin antenna is about
4 feet higher than the other WAP11 unit with the Radio Shack
antenna.....with a 75 foot clear line of sight distance.

- Once the Hawking stopped working with the window closed - I figured I
would get a directional outdoor antenna, or put the antennas outside is some
sort of weather proof case. I had the Belkin so I tried it just for grins.
It worked. I am good.

- The Hawking antenna (including the base) clears the window frame. Only
the top 1.5 inch of the Belkin antenna now clears the frame.

- It's now working - no drop offs, no signal loss. I have been running
continuous ping tests, data transfer tests, etc - all is solid. I am not
going to chase this down anymore since it's working. Clearly opening and
closing the window would break the connection when the cheap Hawking antenna
was at the window. The Belkin stays up with the window closed. That's all
I wanted.

- The Belkin is not supposed to be a high gain antenna - but just an
antenna to a desktop PCI card. It has about 3 foot of wire between the
antenna to the Linksys unit, compared to the 2 foot wire of the Belkin.

- This setup is in the middle of nowhere - no neighbors - no wireless
pollution affecting anyone. Thanks for your concern.

- These are setup as point to point bridge, so they can only talk to each
other's MAC address. SSID broadcast is off and WEP 128 is on.

- The post was to try to figure out the RF and window issues, and why in
theory, a sub-optimal the Belkin el cheapo antenna is working better than
the original Hawking el cheapo "high gain" antenna...not a plea for how to
setup a better directional link. The only reason I went that way is because
I did not have the space to put the Linksys on the sill...so I put the unit
near the window and used an antenna that would sit on the sill.


"Jeff Liebermann" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On Sat, 16 Jul 2005 15:16:22 -0400, <riggor9999> wrote:
>
>>I have setup a 802.11b wireless bridge between two buildings - use the
>>first
>>generation Linksys WAP11 access points (the ones with the USB port).
>
> I have about 5 of those pieces of junk in a pile somewhere. They were
> the first cheap transparent bridge radios in their day. After about 5
> major revisions of the Atmel firmware, and the pieces of junk were
> still locking up all the time, I gave up on them. I'm glad you got
> them working.
>
> Incidentally 1.0 and 1.1 had the USB port. 2.2, 2.6 and 2.8 did not
> have the USB port. 1.0 was junk. 1.1 is improved junk that didn't
> lockup as much. 2.2 and above are fine.
>
>>- I used the hack and boosted the signal to 100% on each.
>
> Good for you. I wonder if the FCC offers a reward for turning in
> spectrum polluters? The problem is that cranking up the power beyond
> the rated and tested levels causes the tx amplifier to spray garbage
> beyond the typical 26MHz of occupied bandwidth for 802.11b. It also
> creates amplitude (envelope) distortion which severely affects the
> ability of the receiver to extract the data. You may crank out more
> RF, but how much of it is in the receiver bandpass, and how much of it
> can be used by the receiver is questionable.
>
> As I recall, the WAP11 running DWL-900AP+ firmware, which is what I
> guess you were doing, doesn't really increase the tx power enough to
> cause a problem. However, if you find that you are running a system
> sufficiently marginal that you need the extra power, methinks you
> should look instead for a better antenna pair or better line of sight,
> as such a marginal system is sure to eventually fail when something
> changes.
>
>>- The one unit is sitting in a basement window. The antenna's were
>>replaced
>>with the radio shack 6db "duck" ones.
>>- The other unit is sitting below a window on a shelf, and I put a single
>>Hawking "high gain 6db" on it ...because it had a 2 ft cable - allowing me
>>to put it antenna on the sill.
>>- The two have clear line of site and are about 75' apart
>
> Are the at the same vertical elevation? If not, the omni antennas
> should be parallel to each other for best performance. I would NOT
> use omni antennas for such a point to point link. The WAP11's have
> RP-TNC connectors and decent antennas are easy to build or buy. My
> version of the common biquad in an outdoor box:
> http://802.11junk.com/jeffl/pics/antennas/biquad2/
>
>>Everything worked great for 2 years. Now the interesting part......
>>
>>The one building had the windows replaced with new Andersen windows.
>>That's
>>the window with the 10" high Hawking H-AI6SIP antenna
>>(http://www.amazon.com/exec/obidos/AS...160163-9816714)
>
> 6dBi of antenna gain (maybe) with about 3ft of RG-316 for a loss of
> 1dB. Net gain is about 5dBi if you ignore connector and adapter
> losses.
>
>>. The bridge now would no longer work. When the window was open - it
>>worked. When the window was closed, it would not. FYI - the original
>>window was a standard wood frame, single pane of glass, not metal or
>>plastic - all wood window.
>
> It's difficult to tell without seeing the window. Many windows have a
> sputtered aluminium coating to improve insulation qualities. Most
> double pane windows do this. Blocks RF quite nicely. The new science
> building at the local university (UCSC) has windows almost impervious
> to RF which is causing problems using cell phones inside the building.
>
> Another possiblity is a vertical difference in elevation as I
> previously asked. The Hawking antenna tend to radiate most of its RF
> near the base of the antenna. If the base was partially obstructed by
> a metal frame window, then you will have some signal loss. Similarly,
> the wooden frame window will pass more RF throught the wooden frame.
>
>>I was going to look at getting an outside antenna and run a wire into the
>>house, etc .... but I had a spare Belkin F5D6900 antenna
>>(http://www.amazon.com/exec/obidos/tg...&s=electronics)
>>that is supposed to be used with a PCI desktop card. It is much shorter -
>>about 3 inches high and just clears the bottom part of the window frame.
>>The Belkin antenna is not a "high gain" antenna.
>
> I'm not sure I would even call it an antenna. Zero specifications on
> the Belkin web pile. No clue as to the gain, length of cable, or type
> of cable. My guess is a simple vertical coaxial antenna with a
> theoretical gain of 2dBi, perhaps 3ft of cheap non-PTFE coax for a
> loss of about 1.6dB, with a net gain of 0.4dBi. Don't bother.
>
> What part of the antenna "just clears" the window frame? This is
> critical as the entire antenna, including parts of the base, must
> clear the window frame. If not, and you get too close to the metal
> frame, you end up detuneing the antenna, creating VSWR, havoc, etc.
>
>>Once I swapped the Hawking with the Belkin - the connection re-established
>>and all is well - when the window is open and closed.
>
> Well, I'm suprised as I would think the Hawking antenna would have
> more gain than the Belkin. Elevation difference (tilt angle) again?
>
>>Anyone have any ideas on why it ..
>>1) the Andersen window blocked the signal, and
>
> Metal frame instead of wood. Aluminium sputtered coating.
>
>>2) why the Belkin antenna worked when the Hawking would not?
>
> Dunno. Many such antennas have a tendency to place much of their RF
> in the upwards direction. Uptilt is more of a problem with high gain
> omni antennas, where you could easily send the signal over everyone's
> heads or to the sky instead of the ground. However, on all counts, I
> would have expected the Belkin antenna to be far worse than the
> Hawking. Assuming everything is working properly, I'm guessing that
> you have a really marginal link, where any small changes in position
> or antenna location will cause difficult to predict changes in antenna
> patterns. For example, reflections from the window frames or other
> objects in the path. Is your system *VERY* sensitive to exact antenna
> location?
>
> However, you're doing this all wrong. Omni antennas are not a good
> idea for a point to point link. Use directional gain antennas. Even
> two coffee can antennas would be a major improvement. Coffee can
> antennas are about 8dBi gain. Single panel antennas are about the
> same. Biquad's can go up to 10dBi gain. Assuming your existing pair
> of omnis each has a gain of 2dBi, a pair of biquads will yield a 16dBi
> increase in fade margin, which is a *HUGE* improvement. Maybe then
> you might turn down the RF power to normal levels and not trash the
> neighborhood.
>
>
> --
> Jeff Liebermann (E-Mail Removed)
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 AE6KS 831-336-2558