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 |

| . 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 | | 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"

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.

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.

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:

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.

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'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.

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

Metal frame instead of wood. Aluminium sputtered coating.

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.

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

- 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.