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Hello,<br>
<br>
Today I participated in a HamWAN field test for the upcoming Field
Day event @ Luther Burbank park. During the testing, a couple very
interesting working RF paths surfaced. Here is the most impressive
one:<br>
<br>
<img src="cid:part1.09060607.05070900@bartk.us" alt=""><br>
<br>
We had setup a dish at the northern tip of Luther Burbank Park, and
aimed it at downtown Seattle (around Columbia Tower). We picked up
a signal from Baldi-S1! The measured distance (time of flight
measurement) was 67km. This means the RF was bouncing off of
downtown Seattle and heading all the way out to Baldi by Enumclaw!
The data throughput measured was about 1.2Mbit each way average,
peaking at 1.5Mbit.<br>
<br>
We moved the dish atop the hill at the park, pointed it at Baldi
through a narrow opening in the closer hill ridges, and did a
follow-up test. The measured distance (time of flight measurement)
in that direct test was 56km: an 11km difference! The measures
aren't very accurate, so the 3km error compared to real physical
distance is within the expected error range. Keep in mind that 3km
is only 10 microseconds in terms of RF signal flight.<br>
<br>
Feeling inspired by this astounding Baldi result, we decided to test
a reflected RF path to the Capitol Park cell site:<br>
<br>
<img src="cid:part2.00080905.03050807@bartk.us" alt=""><br>
<br>
We pointed the dish at a random hillside across the water from
Luther Burbank, and picked up Capitol Park @ up to -73dBm. Bouncing
off this hillside we got 3.5Mbit download and 5Mbit upload speeds to
the Internet.<br>
<br>
I guess the lesson here is: If you don't have a direct path to a
HamWAN cell site, perhaps you can try playing with some indirect
reflected paths to get connected!<br>
<br>
--Bart<br>
<br>
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