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<div class="moz-cite-prefix">Yeah, signal levels bounce around quite
a lot. I see swings much larger than 5dB on my link, and I
attribute that to the trees I'm shooting through.<br>
<br>
We did a few calibrated signal level measures once, from Cougar to
a couple remote spots. The levels did not match theory. We
didn't use the modems, but a proper sine wave signal source and
spectrum analyzer on the receive. To this day, I don't have an
explanation for the deviation from theory. It would be good to
graph your signal levels and see if they're related to anything.
Wind, traffic, temperature, time of day, etc.<br>
<br>
If you wanna get really fancy, you can find a 2nd spot that's
workable somewhere on your property, install a 2nd dish, replace
the modem with a 2-channel one, and start doing spatial
diversity. I don't think anyone's done that yet, although we have
done polarity diversity. You can log the signal strengths from
each channel independently with such a setup, and see if there's
some correlation over time.<br>
<br>
Science!<br>
<br>
--Bart<br>
<br>
<br>
On 04/18/2014 03:19 PM, Dean Gibson AE7Q wrote:<br>
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Prior details in the eMails below ...<br>
<br>
Shortly after the -75dBm report below, I started to see the value
drop to a usual range of -77-80dBm, with occasional excursions
down to -83dBm. I spent three long sessions (one getting wet) out
on the roof, to no avail (I carry an Android tablet logged into
the MikroTik radio, to observe the effects of small adjustments).
The variations did not seem related to rain, although a wet
antenna seems to drop the signal about 2dB. Interestingly, during
the night there was little change, but the commute hours seemed to
generate the most fluctuations. I think that's because the
line-of-sight path runs about 20ft above 132nd St SE, a busy
street connecting I-5 and Highway 9 at the north end of Mill
Creek. Perhaps the signal is bouncing off of vehicles?<br>
<br>
I originally thought that perhaps the decrease from the initial
-75dBm to -78dBm was perhaps due to foliage growth (this is
Spring, after all). However, in the last week I've seen a very
slight increase (1-2dB) in the average signal level, so I don't
know what to make of that. Perhaps someone has been picking
flowers, or Bart has been climbing the SnoCo DEM antenna tower and
making adjustments (just joking)?<br>
<br>
Anyway, the reason for this idle posting is just to record my
observations for others to consider. I have thought of raising my
antenna a couple feet using a similar gutter mount. I then
considered that would probably place the center-of-mass above the
gutter, which would make the whole thing unstable in a strong wind
without a 3rd attachment point. What appears to be the lower
"attachment point" in the images, is in fact just contact bracing,
with gravity providing a constant contact. That's nice when the
whole thing is stable with regard to pivoting around the gutter
axis (as it is now), not so nice otherwise. Yes, I could weight
the lower end down to lower the center of mass, but right now the
weight is enough to make hanging the thing on the gutter
difficult, when standing on a slanted roof ...<br>
<br>
-- Dean<br>
<br>
<div class="moz-cite-prefix">On 2014-03-29 08:09, Dean Gibson AE7Q
wrote:<br>
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Antenna inside (-89dBm), to test the site: <br>
<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.ae7q.com/misc/media/5.9GHz-1.jpg">http://www.ae7q.com/misc/media/5.9GHz-1.jpg</a><br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.ae7q.com/misc/media/5.9GHz-2.jpg">http://www.ae7q.com/misc/media/5.9GHz-2.jpg</a><br>
<br>
Antenna just outside the window (-84dBm), from inside:<br>
<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.ae7q.com/misc/media/5.9GHz-3.jpg">http://www.ae7q.com/misc/media/5.9GHz-3.jpg</a><br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.ae7q.com/misc/media/5.9GHz-4.jpg">http://www.ae7q.com/misc/media/5.9GHz-4.jpg</a>
-- God left a gap in the (many) trees, right in the path to
Paine field ... <br>
<br>
... and from outside ...<br>
<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.ae7q.com/misc/media/5.9GHz-5.jpg">http://www.ae7q.com/misc/media/5.9GHz-5.jpg</a>
-- frontal view<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.ae7q.com/misc/media/5.9GHz-6.jpg">http://www.ae7q.com/misc/media/5.9GHz-6.jpg</a>
-- in the line of fire ...<br>
<br>
Move the antenna 8 feet east for a 9dB signal strength increase
(-75dBm = three green lights (power/Ethernet + two signal
"bars") ...<br>
<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.ae7q.com/misc/media/5.9GHz-7.jpg">http://www.ae7q.com/misc/media/5.9GHz-7.jpg</a>
-- frontal view<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.ae7q.com/misc/media/5.9GHz-8.jpg">http://www.ae7q.com/misc/media/5.9GHz-8.jpg</a>
-- in the line of fire ...<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.ae7q.com/misc/media/5.9GHz-9.jpg">http://www.ae7q.com/misc/media/5.9GHz-9.jpg</a>
-- side view<br>
<br>
The nice thing about the mounting, is that there is NO
attachment to the house, which makes adjustment trivial (sliding
the mounting hooks in the rain gutter). Even the Ethernet cable
goes through pre-existing screening in attic vents. The whole
thing can be removed from the house without a trace in 20
minutes (10 minutes, if one is young and agile, which I am
neither). It's (reasonably) light-weight (another plus, for the
same personal reasons).<br>
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