Saw first field around here tasseling(no not sweet corn), crazy for this area and 4th of July...
Erich Kaiser North Central Tower [email protected] Office: 630-621-4804 Cell: 630-777-9291 On Sat, Jul 4, 2015 at 3:58 PM, Ken Hohhof <[email protected]> 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 <[email protected]> > *Sent:* Saturday, July 04, 2015 3:15 PM > *To:* [email protected] > *Cc:* [email protected] > *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 <[email protected]> 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> > > >
