OK cool, thanks every one. Though I'm not hearing the physical reasons for the numbers, this *IS* more or less the data I was looking for. Which is good enough for now. (KeepItSimpleStupid made a notable attempt at explaining the science though, thank you)
So, what would be a good guess at the loss for only about 2 inches or less of AV cable? The problem I have with most coax that I can find or have on hand is the diameter is so big that you can't use short pieces. It becomes physically hard to work with when it starts getting < 3~5". And even though I believe that you all know exactly what your talking about, I still can't imagine AV would be very much loss
IF IT'S VERY VERY VERY SHORT. Of course, the reason to use short pieces is obvious, any loss is a loss
per distance of cable. So no matter what the cable is (with in reason) if you use only a short amount of it you should have little loss. I think at least it would be far better that normal hookup wire would for the same distance
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Right now I am using the coax out of a laptop that was for it's other antenna (post #1). It is made to be used for WiFi applications and is very very small. Which makes soldering it to the USB dongle and bending short amounts of it much easier and cleaner than other coax would be. The following are some pictures of the RSSI graph of my generic RTL8187L USB dongle attached to the latest two antennas I made for it so far with said coax. When I get some more time I'll replace this cable with AV coax and redo the experiment so we can get good data and compare the results. Then after that I will use longer pieces of each coax type on each antenna type and do everything all over again.
This is a three stage (3 cans) cantenna with just the core conductor as the internal radiant element. The green line is an AP at ~250 meters through some pretty thick woods. The yellow is ~25 meters in the opposite direction, to show antenna directivity. And the blue is in the same room as the antenna, just as a control. (it bows down because I sat back in my chair) Notice the directivity gain. . . and apparently the better stability? I don't understand exactly why it has a flatter line than in the next picture or than the other AP's do in this picture. But it could be software so keep that in mind.
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This graph is the same dongle, PC, and coax, but this time with a Bi-Quad/double diamond as the antenna. The green and yellow color/indicators have switched mac addresses (beyond my control). Understand that this is a software or setting issue and not part of the actual experiment or data. They have only switched color, nothing else has changed. Note that I lost some directivity and some signal with the Bi-Quad, but that it is still quite comparable to the cantenna.
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All antennas were built with very strict attention to details and dimensions. Critical measurements should be tolerant down to .25 mm or better. All the data was collected with the best signal I could get from the farthest AP at the time, higher on the graph is better. None of the AP's were moved during the transition from one test to another, and the antennas were mounted on the same tripod in the same exact spot at the same height and pointing the same direction. The software is inSSIDer downloaded form majorgeeks and the host platform is a Windows 7 PC. I will likely provide pictures of the antennas eventually when I get around to it.