The past two nights have been fade hell. I'm sure tonight will be worse
since it's a little warmer today.
I really like those installs where we get -65 and then end up with -55
when the corn grows in. We get those that go from -60 to -80 over 4-5
weeks too. Oh, and last winter when 12-14" of snow fell in a day or two.
I swear, snow and ice over a nearly flat path creates many more peaks
and nulls.
On 7/4/2015 3:58 PM, Ken Hohhof wrote:
This isn’t corn blocking LOS, it is multipath due to reflections. We
get peaks and valleys >20dB variation and unfortunately they move as
the crops grow. I used to think going higher was the answer, our
typical install height is 15 feet AGL, but even at 25+ feet we see
this. In many cases we get better results going lower, if we can get
below the last null. At the point marked “A” on the graph we lowered
the dish at the customer end, but there was another null below it and
as the corn grew the null moved up.
Best situation is a hill, ridge, or line of trees in the distance so
there is no reflected path.
We’ve had a lot of rain this June so there’s a lot of moisture in the
crops. Usually things get a little better when the soybeans turn
brown or the corn tassels out and starts to dry up.
*From:* Work <mailto:timothy.pct...@gmail.com>
*Sent:* Saturday, July 04, 2015 3:15 PM
*To:* af@afmug.com <mailto:af@afmug.com>
*Cc:* af@afmug.com <mailto:af@afmug.com>
*Subject:* Re: [AFMUG] see crops grow on signal graph
If install by farm scope 9ft or higher if it only works lower then
that don't install it
—
Sent from Mailbox <https://www.dropbox.com/mailbox>
On Sat, Jul 4, 2015 at 3:41 PM, Ken Hohhof <af...@kwisp.com
<mailto:af...@kwisp.com>> wrote:
I would almost say the #1 problem we face is reflections off
cropland,
primarily on 5 GHz customer links. One set of problems occur at
sundown
with no wind. Another occurs as the crops grow. And with crop
rotation, we
might have problems at a customer location where we had none the year
before.
Here is an example where you can literally watch the crops grow
day by day
on the signal graph. Notice the nice roller coaster shaped graph.
There are a couple other things going on at this location. At
point A we
moved the customer's antenna 1-2 feet lower, and changed the mount
to a pipe
with one of the KPP brackets that lets us slide it up and down on
the pipe.
Less than a month later, we're in trouble again. At point B a
storm damaged
the AP omni and the top was open to rain and hornets, it was
replaced a
couple days later.
Strange I don't hear much discussion about this problem, we
probably have it
at 5% of our customers. Maybe most of you don't have flat land and
row
crops.
<crops_growing.png>
<crops_growing.png>
